I don't know why this is happening. When i check the DDMS there is no files dir too. I'm trying to access this folder at my Application subclass. Any idea why this is happening?
I need the application context to be global so I can use on classes that doesn't extends Activity.
package mci.multipratic;
import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;
import android.app.Application;
import android.content.Context;
public class MultiPraticApp extends Application
{
private static MultiPraticApp instance;
public static MultiPraticAppHelper helper;
public MultiPraticApp()
{
instance = MultiPraticApp.this;
helper = new MultiPraticAppHelper();
}
public static Context getContext()
{
return instance;
}
}
class MultiPraticAppHelper
{
private int offsets = 0;
private int productIndex = 0;
private int recipeId = 0;
private Recipe selectedRecipe;
private Properties configFile;
public MultiPraticAppHelper()
{
Context context = MultiPraticApp.getContext();
String path = context.getFilesDir() + "/config.properties";
File file = new File(path);
try
{
FileInputStream fis = new FileInputStream(file);
Properties properties = new Properties();
properties.load(fis);
fis.close();
}catch(Exception ex)
{
ex.printStackTrace();
}
}
My manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="mci.multipratic"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="4" />
<application android:name=".MultiPraticApp"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name">
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.Black.NoTitleBar.Fullscreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".EnableProductsActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.Black.NoTitleBar.Fullscreen">
</activity>
<activity
android:name=".RecipeSelectionActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.Black.NoTitleBar.Fullscreen">
</activity>
<activity
android:name=".ProductAdjustsActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.Black.NoTitleBar.Fullscreen"
>
</activity>
</application>
I believe the problem is you are trying to do initialization in the constructor. Move the code in constructor to OnCreate of Application class.
#Override
public void onCreate() {
super.onCreate();
if(instance != null)
instance = MultiPraticApp.this;
if(helper != null)
helper = new MultiPraticAppHelper();
}
Related
I'm trying to create android app which is able to detect USB devices.
java and xml code are like this.
package com.example.serialtest;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
private TextView mTextView;
private UsbManager mUsbManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mUsbManager = (UsbManager) getSystemService(USB_SERVICE);
mTextView = (TextView) findViewById(R.id.textview);
HashMap<String, UsbDevice> deviceList= mUsbManager.getDeviceList();
if(deviceList == null || deviceList.isEmpty()){
mTextView.setText("no device found");
}else{
String string = "";
for(String name : deviceList.keySet()){
string += name + "\n";
}
mTextView.setText(string);
}
}
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.serialtest">
<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/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-feature android:name="android.hardware.usb.host"
android:required="true"/>
</manifest>
An Android device(Xperia8, android version is 9) required me to give it connection-permission, however, this app always says "no device found".
What should I do?
Please give me some pieces of advise!
I am learning the basics of android programming. Now I have made a Life Cycle test. The list activity works fine, but when I attempt to open the Life Cycle test, the app stops and closes. I have got the same problem on several devices. These are my codes:
(Manifest)
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.badlogic.androidgames"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".AndroidBasicsStarter"
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>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>
</manifest>
(AndroidBasicsStarter.java)
package com.badlogic.androidgames;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class AndroidBasicsStarter extends ListActivity {
String tests[] = { "LifeCycleTest", "SingleTouchTest", "MultiTouchTest", "KeyTest",
"AccelerometerTest", "AssetsTest", "ExternalStorageTest", "SoundPoolTest",
"MediaPlayerTest", "FullScreenTest", "RenderViewTest", "ShapeTest", "BitmapTest",
"FontTest", "SurfaceViewTest"
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, tests));
}
#Override
protected void onListItemClick(ListView list, View view, int position, long id) {
super.onListItemClick(list, view, position, id);
String testName = tests[position];
try {
Class clazz = Class
.forName("com.badlogic.androidgames." + testName);
Intent intent = new Intent(this, clazz);
startActivity(intent);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
(LifeCycleTest.java)
package com.badlogic.androidgames;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class LifeCycleTest extends Activity {
StringBuilder builder = new StringBuilder();
TextView textView;
private void log(String text) {
Log.d("LifeCycleTest", text);
builder.append(text);
builder.append('\n');
textView.setText(builder.toString());
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
textView = new TextView(this);
textView.setText(builder.toString());
setContentView(textView);
log("created");
}
#Override
protected void onResume() {
super.onResume();
log("resumed");
}
#Override
protected void onPause() {
super.onPause();
log("paused");
if (isFinishing()) {
log("finishing");
}
}
}
I use Eclipse on Windows 7. Thank you in advance!
Add your LifeCycleTest activity in AndroidManifest.xml
<activity
android:name=".LifeCycleTest"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
</intent-filter>
</activity>
Include both your activities inside your Manifest file. It should look something like this.
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".AndroidBasicsStarter"
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=".LifeCycleTest"
android:label="#string/app_name" >
</activity>
</application>
I would like to send an array in different application.
So In the first application I have MainActivity. The Activity will start an intent. When I'm trying to make an intent, I found a problem. The problem is ShowArrayActivity "cannot be resolved to a type". Actually ShowArrayActivity class is in another apppication. I have tried to add project in build path, but I have an error message said that a cycle was detected in the build path of project 'sendIntent'..
package com.example.sendintent;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import com.example.sendintent.DisplayMessageActivity;
public class MainActivity extends Activity {
public static final String ARRAYS_COUNT = "com.example.sendintent.MainActivity.ARRAYS_COUNT";
public static final String ARRAY_INDEX = "com.example.sendintent.MainActivity.ARRAY_INDEX";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#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;
}
public void sendMessage(View view)
{
final String data[][] = new String[][]
{{"Car","75","loaded"},
{"Motor","25","loaded"},
{"Truck","30","loaded"},
{"Bike","40","loaded"},
{"Boat","10","loaded"}};
Bundle bundle = new Bundle();
int count = data.length;
bundle.putInt(ARRAYS_COUNT, count);
for (int i = 0; i < count; i++)
bundle.putStringArray(ARRAY_INDEX + i, data[i]);
Intent intent = new Intent(this, ShowArrayActivity.class); ---->ERROR
intent.putExtras(bundle);
startActivity(intent);
}
}
In Manifest I have declare
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sendintent"
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.example.sendintent.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="com.example.sendintent.DisplayMessageActivity"
android:parentActivityName="com.example.sendintent.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.sendintent.MainActivity" />
</activity>
<service android:name="com.example.sendintent.MainActivity" />
<receiver android:name="com.example.receiver.MainActivityReceiver">
<intent-filter>
<action android:name="com.example.sendintent.MainActivity.ARRAYS_COUNT"/>
<action android:name="com.example.sendintent.MainActivity.ARRAYS_INDEX"/>
</intent-filter>
</receiver>
</application>
</manifest>
In another application, I have declare the receiver for the intent. It called MainActivityReceiver
package com.example.receiver;
import java.util.ArrayList;
import com.example.sendintent.MainActivity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class MainActivityReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
intent.setClass(context, MainActivity.class);
context.startService(intent);
}
}
I have another class called ShowArrayAcivity:
package com.example.receiver;
import java.util.ArrayList;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class ShowArrayActivity extends Activity {
public String[][] data;
public static final String ARRAYS_COUNT = "com.example.sendintent.MainActivity.ARRAYS_COUNT";
public static final String ARRAY_INDEX = "com.example.sendintent.MainActivity.ARRAY_INDEX";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
int count = bundle.getInt(ShowArrayActivity.ARRAYS_COUNT, 0);
ArrayList<String[]> arrays = new ArrayList<String[]>(count);
for (int i = 0; i < count; i++)
arrays.add(bundle.getStringArray(ShowArrayActivity.ARRAY_INDEX + i));
data = arrays.toArray(new String[][]{});
}
}
#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;
}
}
In Manifest for receiver application
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.receiver"
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.example.receiver.ShowArrayActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name="com.example.sendintent.MainActivity" />
<receiver android:name="com.example.receiver.MainActivityReceiver">
<intent-filter>
<action android:name="com.example.sendintent.MainActivity.ARRAYS_COUNT"/>
<action android:name="com.example.sendintent.MainActivity.ARRAYS_INDEX"/>
</intent-filter>
</receiver>
</application>
</manifest>
In receiver application, It won't show the array from sendIntent application in Interface. I just want to know the way to use broadcast and intent. So if I run in debug mode,in ShowArrayActivity, the variable data will containt the result of the intent.
So my questions is,why I can't use another class when I try to send the intent? Did I forgot something to implement for madethe communication between 2 application?
Intent intent = new Intent(this, ShowArrayActivity.class);
this way you tell activity to find ShowArrayActivity within this Application and launch it. It fails as Application can't find it in it's manifest.
Create Intent with action.
Intent intent = new Intent (NAME_OF_THE_FILTER);
then replace string it second manifest
assuming
public static final String NAME_OF_THE_FILTER = "com.myapp.myfilter"
<intent-filter>
<action android:name="com.myapp.myfilter"/>
</intent-filter>
I'm trying to get this to open an url when the icon is selected/clicked, but I get Syntax error on tokens, delete these tokens on the line String url =
String url = "http://www.google.co.uk/";
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
Manifest:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.openurl"
android:versionCode="1"
android:versionName="1.0" >
<application>
<activity android:name="OpenURL" 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>
I've now got a bit further on this one but when I load the apk file the icon opens the browser with 2 windows - blank and the url. I;m also unable to use the back button to close the browser - it keeps opening the url. How can I correct these issues?
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="14" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name">
<activity
android:name="com.example.myapp.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>
package com.example.myapp;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String url = "http://www.google.co.uk";
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
}
Many thanks again!
This
String url = "http://www.google.co.uk/";
can never be the first line of a java file.
You file need a structure like:
package a.b.c; // optional
import java.util.List; // optional
public class ClassName { // mandatory
// your code
} // mandatory
If this fixes your error, you should consider reading a Java tutorial.
First of all add the permission for internet in your manifest:
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
then your main should be like this:
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.yourmainlayout);
Button button = (Button) findViewById(R.id.yourbuttonid);
button.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
String url = "http://www.google.co.uk/";
Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(i);
}});
}
}
I'm trying to use build-in android's Application.class, but every time I want to use it, I get a NullPointerException. I'm going to share some pieces of code to show how I'm accessing my custom class, which extends Application:
This is the class I'm using:
public class SharedProperties extends Application {
private String currentCategory;
private String dataNews;
public SharedProperties() {
super();
}
public String getCurrentCategory() {
return currentCategory;
}
public void setCurrentCategory(String currentCategory) {
this.currentCategory = currentCategory;
}
public String getDataNews() {
return dataNews;
}
public void setDataNews(String dataNews) {
this.dataNews = dataNews;
}
}
...and this how I set and get values from it:
SharedProperties shared = ((SharedProperties)getApplication());
shared.setCurrentCategory(categories[currentCategory]);
shared.setDataNews(rssList.get(position).getData());
......
SharedProperties shared = ((SharedProperties)getApplication());
String category = shared.getCurrentCategory();
String newstext = shared.getDataNews();
Is the way I'm accessing it wrong or I miss something into the SharedProperties.class?
Here is my manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.news.reader"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="4" />
<application android:name="SharedProperties" android:icon="#drawable/logo" android:label="#string/app_name">
<activity android:name="Splash"
android:label="#string/app_name"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="Home"
android:label="#string/app_name"
android:screenOrientation="sensor"
android:configChanges="keyboardHidden|orientation" />
<activity android:name="News"
android:label="#string/app_name"
android:screenOrientation="sensor"
android:configChanges="keyboardHidden|orientation" />
</application>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission>
</manifest>
Put the android:name attribute in the <application> entry which contains all your activities, not as a separate entity. Change it to be the fully-qualified name of the class (e.g., com.this.is.your.package.SharedPreferences).
Also, don't do this. Use a singleton. Please.
For starters, the name of your Application class is SharedProperties, not MyApp, so it should be cast to that.
Secondly, in order for Android to know to use your custom Application, you need to say so in your AndroidManifest.xml like so:
<application
android:name="SharedProperties"
android:icon="#drawable/icon"
android:label="#string/app_name">
I had similar problem, don exactly remember what i did , but do try adding
public SharedProperties()
{
super();
}