I am working in Eclipse, My app edit two integers and click the button so the app will show the average, but when i operate the app in my device, when i click the button it stop working and show message "application has been stopped"
XML File :
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:ems="10" />
<EditText
android:id="#+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginTop="22dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="28dp"
android:text="Button" />
<TextView
android:id="#+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="#+id/button1"
android:layout_below="#+id/button1"
android:layout_marginTop="72dp"
/>
</RelativeLayout>
JAVA File :
package com.example.mine;
//import com.example.mine.R;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
EditText num1, num2;
Button count;
TextView text;
String e1, e2;
int q, i, r;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
count = (Button) findViewById(R.id.button1);
num1 = (EditText) findViewById(R.id.editText1);
num1 = (EditText) findViewById(R.id.editText2);
text = (TextView) findViewById(R.id.text);
count.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
// TODO Auto-generated method stub
e1 = num1.getText().toString();
e2 = num2.getText().toString();
q = Integer.parseInt(e1);
i = Integer.parseInt(e2);
r = (i + q) / 2;
text.setText("the average is " + r);
// text.setText(Integer.toString(r));
// text.setText(r+"");
}
});
}
}
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mine"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.mine.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Logcat is empty
Look at these two lines:
q = Integer.parseInt(e1);
i = Integer.parseInt(e2);
If e1 or e2 is not a number, parseInt will throw an IllegalArgument exception. In general, you should always expect parseInt has potential to throw an exception with user input - so a try/catch block is almost always warranted.
I don't seen any default text being set for edit1 or edit2, so without a logcat dump of the exception crash, that's my best guess.
Related
This question already has answers here:
Unfortunately MyApp has stopped. How can I solve this?
(23 answers)
findViewById() returns null when I call it in onCreate()
(3 answers)
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 1 year ago.
I am trying to open up the second activity (MainActivity2) via a button but the application crashes every time, I am not quite sure how to solve this. I want to be able to open to the second screen to use the second activity. Thank you for your help. (Having trouble with separating the code, so I have used lines)
Activity main xml + Main activity
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="241dp"
android:text="Activity1"
android:id="#+id/textView"/>
<Button
android:id="#+id/button"
android:layout_width="375dp"
android:layout_height="101dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="275dp"
android:text="open password generator" />
</RelativeLayout>
**Main activity**
package com.example.menutest;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
private Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openActivity2();
}
});
}
public void openActivity2() {
Intent intent = new Intent(this, MainActivity2.class);
startActivity(intent);
}
}
activity main2 + activity main 2 XML + manifest
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity2">
<TextView
android:id="#+id/textView3"
android:layout_width="203dp"
android:layout_height="85dp"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginStart="67dp"
android:layout_marginLeft="67dp"
android:layout_marginTop="264dp"
android:hapticFeedbackEnabled="false"
android:textColor="#070505"
android:textSize="18sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.653"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="19dp"
android:layout_marginLeft="19dp"
android:layout_marginBottom="304dp"
android:hapticFeedbackEnabled="true"
android:soundEffectsEnabled="false"
android:text="Generate strong password"
android:textSize="18sp"
android:textStyle="bold"
app:backgroundTint="#36A13A"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.59" />
</RelativeLayout>
***Mainactivity2***
package com.example.menutest;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.Random;
public class MainActivity2 extends AppCompatActivity {
Button button;
TextView textView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
button = (Button)findViewById(R.id.button);
textView = (TextView)findViewById(R.id.textView);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(generateString(16));
}
});
}
private String generateString(int length) {
char[] chars ="/.,MNBVCXZ;LKJHGFDSAPOIUYTREWQ[]#=-)0987654321!£$*&qwertyuiopzxcvbnmasdfghjkl(".toCharArray();
StringBuilder stringBuilder = new StringBuilder();
Random random = new Random();
for ( int i=0; i<length;i++)
{
char c = chars[random.nextInt(chars.length)];
stringBuilder.append(c);
}
return stringBuilder.toString();
}
}
***AndroidManifest xml***
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.menutest">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.MENUTEST">
<activity android:name=".MainActivity2"></activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
..........................................................................
Mainactivity2
button = (Button)findViewById(R.id.button4);
textView = (TextView)findViewById(R.id.textView3);
I was trying to use user input name for later use but Once i run the app this is closed by saying unfortunately your app has stopped. I have provided Main activity,Layout xml and android manifest codes. Please anyone answer this . I am newbie in android and cant figure out the error.
Main_activity
package rupakthapa.droiddynasty.com.interactivestory2;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import static android.R.attr.duration;
import static android.R.attr.name;
public class MainActivity extends AppCompatActivity {
private EditText mNameField;
private Button mButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNameField = (EditText) findViewById(R.id.nameField);
mButton = (Button) findViewById(R.id.startButton);
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String a= mNameField.getText().toString();
Context context = getApplicationContext();
int length = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(context, a, length);
toast.show();
}
});
}
}
XML
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_main"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="rupakthapa.droiddynasty.com.interactivestory2.MainActivity">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#mipmap/ic_launcher"
android:id="#+id/imageView"
android:adjustViewBounds="true"
android:scaleType="fitXY"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="149dp"
android:contentDescription="startImage"/>
<TextView
android:layout_width="match_parent"
android:id="#+id/nameField"
android:hint="Enter YOur Name"
android:layout_above="#+id/startButton"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="11dp"
android:maxLength="30"
android:layout_marginLeft="10dp"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_height="wrap_content"
android:textSize="16sp"/>
<Button
android:text="Start your adventure"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/startButton"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
</RelativeLayout>
Android Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest package="rupakthapa.droiddynasty.com.interactivestory2"
xmlns:android="http://schemas.android.com/apk/res/android">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
There is a problem here. You dont have EditText in your layout.
mNameField = (EditText) findViewById(R.id.nameField);
In your layout you should change TextView to EditText
<EditText
android:layout_width="match_parent"
android:id="#+id/nameField"
android:hint="Enter YOur Name"
android:layout_above="#+id/startButton"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginBottom="11dp"
android:maxLength="30"
android:layout_marginLeft="10dp"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_height="wrap_content"
android:textSize="16sp"/>
The Start class:
It as a very simple program, i designed two screen, and by pressing a button on the main screen i wanted the app to open the second screen, but unfortunately its not happening, the app keeps crushing over and over again.
package com.example.snakesnladders;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class Start extends Activity implements OnClickListener {
Button start, settings;
TextView snakes, and, ladders;
ImageView snakePic;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mainscreen);
init();
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
}
private void init() {
start = (Button) findViewById(R.id.btStart);
settings = (Button) findViewById(R.id.btSettings);
snakes = (TextView) findViewById(R.id.tvSnakes);
and = (TextView) findViewById(R.id.tvAnd);
ladders = (TextView) findViewById(R.id.tvLadders);
snakePic = (ImageView) findViewById(R.id.snakePic);
start.setOnClickListener(this);
settings.setOnClickListener(this);
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btStart:
break;
case R.id.btSettings:
Intent i = new Intent("com.example.snakesnladders.SET");
startActivity(i);
break;
default: break;
}
}
}
The Set class:
package com.example.snakesnladders;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class Set extends Activity implements OnClickListener {
Button sound, difficulty, back;
TextView settings;
ImageView snakePic;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.setscreen);
init();
}
private void init() {
sound = (Button) findViewById(R.id.btSound);
difficulty = (Button) findViewById(R.id.btDifficulty);
back = (Button) findViewById(R.id.btBack);
settings = (TextView) findViewById(R.id.tvSetPage);
snakePic = (ImageView) findViewById(R.id.setSnakePic);
sound.setOnClickListener(this);
difficulty.setOnClickListener(this);
back.setOnClickListener(this);
}
#Override
public void onClick(View view) {
// TODO Auto-generated method stub
switch (view.getId()) {
case R.id.btSound:
String s = sound.getText().toString();
if (s.equals("Sound:on")) {
sound.setText("Sound:off");
ControlSounds.player.stop();
} else {
sound.setText("Sound:on");
ControlSounds.player.start();
}
break;
case R.id.btDifficulty:
break;
case R.id.btBack:
Intent i = new Intent(Set.this, Start.class);
startActivity(i);
finish();
break;
}
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
}
}
The manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.snakesnladders"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".Start"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Set"
android:label="#string/app_name" >
<intent-filter>
<action android:name="com.example.snakesnladders.SET" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
mainscreen.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="175dp"
android:orientation="vertical" >
<TextView
android:id="#+id/tvSnakes"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_gravity="center"
android:text="Snakes"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="#color/green"
android:textSize="30sp" />
<TextView
android:id="#+id/tvAnd"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_gravity="center"
android:text="#string/and"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="#color/green"
android:textSize="30sp" />
<TextView
android:id="#+id/tvLadders"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_gravity="center"
android:text="Ladders"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="#color/green"
android:textSize="30sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="125dp"
android:orientation="vertical" >
<Button
android:id="#+id/btStart"
android:layout_width="250dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A8A8"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="10"
android:text="Start New Game"
android:textColor="#FFFFFF"
android:textSize="30sp" />
<Button
android:id="#+id/btSettings"
android:layout_width="250dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A8A8"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="10"
android:text="Settings"
android:textColor="#FFFFFF"
android:textSize="30sp" />
</LinearLayout>
<ImageView
android:id="#+id/snakePic"
android:layout_width="wrap_content"
android:layout_height="125dp"
android:layout_gravity="center"
android:layout_weight="0.47"
android:background="#color/black"
android:src="#drawable/snake" />
</LinearLayout>
setscreen.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/black"
android:orientation="vertical" >
<TextView
android:id="#+id/tvSetPage"
android:layout_width="wrap_content"
android:layout_height="60dp"
android:layout_gravity="center"
android:text="Settings"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="#color/green"
android:textSize="40sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/black"
android:orientation="vertical" >
<Button
android:id="#+id/btSound"
android:layout_width="250dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A8A8"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="10"
android:text="Sound:on"
android:textColor="#FFFFFF"
android:textSize="30sp" />
<Button
android:id="#+id/btDifficulty"
android:layout_width="250dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A8A8"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="10"
android:text="Difficulty:easy"
android:textColor="#FFFFFF"
android:textSize="30sp" />
<Button
android:id="#+id/btBack"
android:layout_width="250dp"
android:layout_height="60dp"
android:layout_gravity="center"
android:background="#drawable/buttonshape"
android:shadowColor="#A8A8A8"
android:shadowDx="0"
android:shadowDy="0"
android:shadowRadius="10"
android:text="Back To Menu"
android:textColor="#FFFFFF"
android:textSize="30sp" />
</LinearLayout>
<ImageView
android:id="#+id/setSnakePic"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:layout_weight="0.25"
android:background="#color/black"
android:src="#drawable/snake1" />
</LinearLayout>
Change this
Intent i = new Intent("com.example.snakesnladders.SET");
startActivity(i);
To
Intent i = new Intent(Start.this,Set.class);
startActivity(i);
And Change this
<activity
android:name=".Set"
android:label="#string/app_name" >
<intent-filter>
<action android:name="com.example.snakesnladders.SET" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
To
<activity
android:name=".Set"
android:label="#string/app_name" >
</activity>
Use Explicit Intent's
To know why read
http://developer.android.com/guide/components/intents-filters.html
Explicit intents specify the component to start by name (the
fully-qualified class name). You'll typically use an explicit intent
to start a component in your own app, because you know the class name
of the activity or service you want to start. For example, start a new
activity in response to a user action or start a service to download a
file in the background.
I have this problem that just seems strange.
I have this Android View with six buttons and when i click on one of them(the only one with the action defined apart from the exit button), it gives me a RuntimeError.
The Activity is declared on the manifest, and this is why i don't understand my error.
Can someone please help me with this.
I would really appreciate it :)
So here's my code:
package com.example.calendar;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity implements OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View createButton = findViewById(R.id.btn_create);
View deleteButton = findViewById(R.id.btn_delete);
View moveButton = findViewById(R.id.btn_move);
View searchButton = findViewById(R.id.btn_search);
View translateButton = findViewById(R.id.btn_translate);
View exitButton = findViewById(R.id.exit);
createButton.setOnClickListener(this);
deleteButton.setOnClickListener(this);
moveButton.setOnClickListener(this);
searchButton.setOnClickListener(this);
translateButton.setOnClickListener(this);
exitButton.setOnClickListener(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.btn_create:
Intent i = new Intent(this, CreateAppointment.class);
startActivity(i);
break;
case R.id.exit:
finish();
break;
}
}
}
My layout is like this:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:background="#color/background"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="225dp"
android:orientation="vertical"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin" >
<CalendarView
android:id="#+id/calendar"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
<TableLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginBottom="2dip"
android:layout_marginTop="2dip"
android:stretchColumns="*" >
<TableRow>
<Button
android:id="#+id/btn_create"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/create" />
<Button
android:id="#+id/btn_viewEdit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/viewEdit" />
</TableRow>
<TableRow>
<Button
android:id="#+id/btn_delete"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/delete" />
<Button
android:id="#+id/btn_move"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/move" />
</TableRow>
<TableRow>
<Button
android:id="#+id/btn_search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/search" />
<Button
android:id="#+id/btn_translate"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/translate" />
</TableRow>
</TableLayout>
<Button
android:id="#+id/exit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/exit"/>
</LinearLayout>
And the manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.calendar"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.calendar.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".CreateAppointment"
android:theme="#android:style/Theme.Dialog"
android:label="#string/create" >
</activity>
</application>
</manifest>
You have to define correctly what kind of views ares using in onCreate()
View createButton = findViewById(R.id.btn_create);
for example:
since you are using a Button:
<Button
android:id="#+id/btn_create"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/create" />
Make the cast as button:
Button createButton = (Button)findViewById(R.id.btn_create);
try this:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button createButton = (Button)findViewById(R.id.btn_create);
Button deleteButton = (Button)findViewById(R.id.btn_delete);
Button moveButton = (Button)findViewById(R.id.btn_move);
Button searchButton = (Button)findViewById(R.id.btn_search);
Button translateButton = (Button)findViewById(R.id.btn_translate);
Button exitButton = (Button)findViewById(R.id.exit);
createButton.setOnClickListener(this);
deleteButton.setOnClickListener(this);
moveButton.setOnClickListener(this);
searchButton.setOnClickListener(this);
translateButton.setOnClickListener(this);
exitButton.setOnClickListener(this);
}
Hey i'm brand new to programming and i need some help,
i'm doing a project for school and it's an android app where the user inputs words to a text field and then those words are used to create a story, like mad libs. I can not seem to see what is wrong with my code here when i debug on my phone it just shows a white screen. Could someone point out to me what i'm doing wrong? thanks...
MainActivity.java:
package com.joe.madlibs;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
EditText Noun, Adj, Name, Verb, Verb2, Noun2, Adj2;
Button Submit;
TextView Story;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Noun = (EditText) findViewById(R.id.noun1);
Adj = (EditText) findViewById(R.id.adjective1);
Name = (EditText) findViewById(R.id.name1);
Verb = (EditText) findViewById(R.id.verb1);
Verb2 = (EditText) findViewById(R.id.verb2);
Noun2 = (EditText) findViewById(R.id.noun2);
Adj2 = (EditText) findViewById(R.id.adj2);
String noun = Noun.getText().toString();
String adj = Adj.getText().toString();
String name = Name.getText().toString();
String verb = Verb.getText().toString();
String verb2 = Verb2.getText().toString();
String noun2 = Noun2.getText().toString();
String adj2 = Adj2.getText().toString();
Submit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
<EditText
android:id="#+id/noun1"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/linearLayout1"
android:layout_alignTop="#+id/linearLayout1"
android:ems="10"
android:hint="#string/noun" >
</EditText>
<EditText
android:id="#+id/verb1"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/name1"
android:layout_alignBottom="#+id/name1"
android:layout_alignRight="#+id/storyBox"
android:ems="10"
android:hint="#string/verb" />
<EditText
android:id="#+id/adjective1"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/noun1"
android:layout_alignBottom="#+id/noun1"
android:layout_alignLeft="#+id/verb1"
android:ems="10"
android:hint="#string/adjective" />
<EditText
android:id="#+id/name1"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/noun1"
android:layout_below="#+id/noun1"
android:ems="10"
android:hint="#string/name" />
<EditText
android:id="#+id/verb2"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/name1"
android:layout_below="#+id/name1"
android:ems="10"
android:hint="#string/verb" />
<EditText
android:id="#+id/adj2"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/verb1"
android:layout_below="#+id/verb1"
android:ems="10"
android:hint="Adjective" />
<EditText
android:id="#+id/noun2"
android:layout_width="140dp"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/verb2"
android:layout_below="#+id/verb2"
android:ems="10"
android:hint="Noun" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="Click here to get your story!" />
<TextView
android:id="#+id/storyBox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/noun2"
android:layout_below="#+id/button1"
android:layout_marginTop="18dp"
android:text="This is where your story will go!"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
Manifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.Joe.madlibs"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.Joe.madlibs.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Umm... where are you instantiating your Submit button before trying to set an onClickListener on it? I see where you declare it, but you aren't instantiating it.
Add:
Submit = (Button)findViewById(R.id.button1);
right before
Submit.setOnClickListener(new View.OnClickListener() {
and watch. It's gonna be like magic.
One more thing about coding conventions (style): when you name your instance variables, use the headlessCamelCase convention. Names with CamelCase/InitCaps (first letter of each word capitalized) should only be used when you name your class (the pattern for an object) as opposed to when you refer to an instance of that class (the actual object).
Wrong:
// An instance of Button class
Button Submit;
Right:
// An instance of Button class:
Button submit;
When it comes to compound names (more than one word), headlessCamelCase means you capitalize the first letter of each word, except the first word.
Right:
// An instance of Button class:
Button myVeryElderlyMotherJustSatUponNapoleonsSubmitButton;