Develop Reference

Add a text field on button click to second main activity

I need to add text field depends on the number the user added in the number text field to the second main activity. I already have a button that open onClick a new MainActivity but I need also to add text fields in the second MainActivity depends the number added.
I tried adding text fields on actionListeners but still not working.
public class MainActivity extends AppCompatActivity {
private Button submit_textfield;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
submit_textfield = (Button) findViewById(R.id.submit_textfield);
submit_textfield.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
openActivity2();
}
});}
public void openActivity2() {
Intent intent = new Intent(this, Main2Activity.class);
startActivity(intent);
}
}
The results must be: the user enters 5 and click submit the page redirect and creates 5 text fields. Thank You.

the user enters 5 and click submit the page redirect and creates 5
textfields
For this, you need to pass the text value into another class by using Intent.
Then you can receive the value by using getIntExtra in Main2Activity.
public void openActivity2() {
Intent intent = new Intent(this, Main2Activity.class);
intent.putExtra("num",submit_textfield.getText());
startActivity(intent);
}
After get the num value, you can create the TextView dynamically based on the number.
Main2Activity
int num = getIntent().getIntExtra("num",0);
LinearLayout linearLayout = findViewById(R.id.myLinearLayout);
for (int i = 0; i < num; i++) {
final TextView rowTextView = new TextView(this);
rowTextView.setText("Value " + i);
myLinearLayout.addView(rowTextView);
}
Output

For achieving this you have to add a dynamic linear layout in which you will add textviews on run time nad firstly you have to pass that number into the intent by putExtra method.
public void openActivity2() {
Intent intent = new Intent(this, Main2Activity.class);
intent.putExtra("number",submit_textfield.getText().toString());
startActivity(intent);
}
Now you just have to get this value in the next activity and start a for loop for this value and add runtime textviews in the linear layout.
int number =0;
if(getIntent().getExtras()!=null){
number = Integer.parseInt(getIntent().getStringExtra("number"));
}
LinearLayout ll= findViewById(R.id.ll_layout);
for (int i = 0; i < num; i++) {
final TextView tv_text= new TextView(this);
tv_text.setText("Value " + i);
ll.addView(tv_text);
}
if you want to set these textviews in vertical orientation then you just have to add the params to the linear layout as mentioned below:
ll.setOrientation(LinearLayout.VERTICAL);

Opening another activity based on number of filled editTexts

The app has a MainActivity with 6 editText fields, and a button. There are 5 more activities, named Activity2, Activity3, etc. Now, When a user enters names in editText fields, and press a button, the app should find out how many editText fields are filled, and open the activity with a corresponding number in it's name.
Example:
If only one field is filled, a toast should appear, saying More players.
If two fields are filled, app opens Activity2.
If three fields are filled, app opens Activity3, etc.
Now, to the problem. I am missing something out, and can't find out what. Here is MainActivity.java
public class MainActivity extends AppCompatActivity {
private EditText editText1,editText2,editText3,editText4,editText5,editText6;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn = findViewById(R.id.btn);
editText1 = findViewById(R.id.editText1);
editText2 = findViewById(R.id.editText2);
editText3 = findViewById(R.id.editText3);
editText4 = findViewById(R.id.editText4);
editText5 = findViewById(R.id.editText5);
editText6 = findViewById(R.id.editText6);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int filledFileds = countFilledFields();
Log.d("filled", String.valueOf(filledFileds));
Class newClass = MainActivity.class;
switch (filledFileds){
case 1:
Context context = getApplicationContext();
CharSequence text = "You need more players!";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
break;
case 2:
newClass = Activity2.class;
System.out.println("Activity2");
break;
case 3:
newClass = Activity3.class;
System.out.println("Activity3");
break;
case 4:
newClass = Activity4.class;
System.out.println("Activity4");
break;
case 5:
newClass = Activity5.class;
System.out.println("Activity5");
break;
case 6:
newClass = Activity6.class;
System.out.println("Activity6");
break;
default:
}
Intent intent = new Intent(MainActivity.this, newClass);
}
});
}
private int countFilledFields() {
ArrayList<EditText> editTexts = new ArrayList<>();
editTexts.add(editText1);
editTexts.add(editText2);
editTexts.add(editText3);
editTexts.add(editText4);
editTexts.add(editText5);
editTexts.add(editText6);
int filledNumber = 0;
for(int i = 0;i < editTexts.size() ;i++){
if(editTexts.get(i).getText()!=null && !editTexts.get(i).getText().toString().matches("")){
filledNumber += 1;
}
}
return filledNumber;
}
}
The log shows the exact number, something is not working...

Here is your click listener, with the switch omitted for brevity:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int filledFileds = countFilledFields();
Log.d("filled", String.valueOf(filledFileds));
Class newClass = MainActivity.class;
switch (filledFileds){
...
}
Intent intent = new Intent(MainActivity.this, newClass);
}
The problem is at the very end: you've created an Intent object ... but you're not doing anything with it. Probably you have just forgotten a startActivity() call:
Intent intent = new Intent(MainActivity.this, newClass);
startActivity(intent);
Also, looking this over, you have a problem with the case where the user only enters one EditText. As written, you'll still try to start a new activity (you'll just start a new copy of the same MainActivity, which is probably a bad idea). A better idea would be to only start the new activity if the user fills out enough EditTexts:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int filledFileds = countFilledFields();
Log.d("filled", String.valueOf(filledFileds));
Class newClass = null;
switch (filledFileds){
...
}
if (newClass != null) {
Intent intent = new Intent(MainActivity.this, newClass);
startActivity(intent);
}
}

You're missing one thing:
startActivity(intent);

Add values to ArrayList from different activity

I'm trying to create an app like shopping cart
Using this to access my database http://www.tutecentral.com/restful-api-for-android-part-2/
And i'm stuck at adding products to cart, so far I understand that the selected products go to arraylist in a few tutorials. In the code below I have two Activities, the MaterialView (this shows the details of the materials and has the option to add to cart), and the MaterialCart (shows the list of selected products.)
this is the block of code in MaterialView to send the values to MaterialCart
ButtonAdd.setOnClickListener(new View.OnClickListener(){
public void onClick (View view){
Intent i=new Intent(MaterialView.this, MaterialCart.class);
i.putExtra("mID", mid);
i.putExtra("name", Name.getText().toString());
i.putExtra("qty", Qty.getText().toString());
i.putExtra("price", Price.getText().toString());
i.putExtra("stock", Stock.getText().toString());
i.putExtra("rqQty", RqQty.getText().toString());
startActivity(i);
Toast.makeText(MaterialView.this, "Added Succesfully.", Toast.LENGTH_LONG).show();
}
} );
I have used Intent to pass the values (I'm pretty sure this method is wrong, I also tried calling the MaterialCart class itself to access the arrayList so I can add values and it didn't work)
This is the block of codes in my MaterialCart to receive the values
public class MaterialCart extends Activity {
final ArrayList<PropertyCartTable> materialProperties = new ArrayList<>();
#SuppressLint("LongLogTag")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_material_cart);
Intent i = new Intent();
Bundle extras = getIntent().getExtras();
try{
String Name = extras.getString("name");
String Qty = extras.getString("qty");
String Price = extras.getString("price");
String Stock = extras.getString("stock");
String RqQty = extras.getString("rqQty");
String ID = extras.getString("mID");
Log.d("EXTRAS:", Name + " " + Qty + " " + ID);
materialProperties.add(new PropertyCartTable( ID,Name,Qty,Price,Stock,RqQty));
getIntent().removeExtra("Name");
getIntent().removeExtra("Qty");
getIntent().removeExtra("Price");
getIntent().removeExtra("Stock");
getIntent().removeExtra("RqQty");
getIntent().removeExtra("MID");
}
catch (Exception h){
Log.d("Exception!",h.toString());
}
// materialProperties.add(array);
Log.d("MaterialView.Cart isEmpty", String.valueOf(materialProperties.isEmpty()));
if(materialProperties.isEmpty()) {
Toast.makeText(this, "You have no materials to request.", Toast.LENGTH_LONG).show();
i = new Intent(MaterialCart.this, ProductDetails.class);
startActivity(i);
}else{
ArrayAdapter<PropertyCartTable> adapter = new propertyArrayAdapter(this, 0, materialProperties);
ListView listView = (ListView) findViewById(R.id.lv_materialcart);
listView.setAdapter(adapter);
}
}
The codes work for receiving the values, but when I go back to the materialView (or choose another product) the ArrayList doesn't append the values.
What I'm trying to achieve here is to add the values from the MaterialView (even if the user adds many prodducts) to MaterialCart's ArrayList.

You can let your Application contain the data:
public class MyApp extends Application {
private static List<String> data = new ArrayList<>();
public static void addItem(String item) {
data.add(item);
}
public static List<String> getData() {
return data;
}
}
And when button is clicked:
ButtonAdd.setOnClickListener(new View.OnClickListener(){
public void onClick (View view){
MyApp.addItem(your item);
Intent i=new Intent(MaterialView.this, MaterialCart.class);
startActivity(i);
}
} );
And in MaterialCart.class:
List<String> data = MyApp.getData();
But remember:data will be clear when app is closed.And if you want save it locally,you need to use SharedPreferences

How to start another activity and start a method inside it?

As soon as the setOnClickListener executes I want to start another activity and transmit the variable cn.getID() to it. When inside the other activity I want to immidietaly start the method findlocation and give cn.getID() to it.
The method findLocation is not finished yet. The idea is, once it gets the ID of the other activities button, i can search with sqllite in my database for the place it belongs to, get longitude and latitude and tell mapcontroller focus the world map on this point.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.verladestellen);
final DB_Verladestellen db = new DB_Verladestellen(this);
List<DB_Place> placeList = db.getAllDBPlaces();
final LinearLayout layout = (LinearLayout) findViewById(R.id.verladestellen_liste);
for (final DB_Place cn : placeList) {
final LinearLayout row = new LinearLayout(this);
row.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
Button place = new Button(this);
place.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
place.setText(cn.getName());
place.setId(cn.getID());
row.addView(place);
row.setId(cn.getID());
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) place.getLayoutParams();
params.weight = 1.0f;
place.setLayoutParams(params);
place.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Here I want to call the method to start the other activity
//and transmit cn.getID().
openMap(null);
}
});
layout.addView(row);
}
}
//The method to start the other activity
public void openMap(View view) {
Intent intent = new Intent(this, UI_MainActivity.class);
startActivity(intent);
}
This is the method from inside the new activity I want to execute immidietaly after it has started:
public void findLocation(View view){
MapView map = (MapView) findViewById(R.id.map);
IMapController mapController = map.getController();
mapController.setZoom(17);
GeoPoint myLocation = new GeoPoint(PLACEHOLDER X , PLACEHOLDER Y);
mapController.animateTo(myLocation);
}
EDIT:
#Murat K. After some edits this is my whole class now:
public class UI_Verladestellen extends AppCompatActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.verladestellen);
final DB_Verladestellen db = new DB_Verladestellen(this);
List<DB_Place> placeList = db.getAllDBPlaces();
final LinearLayout layout = (LinearLayout) findViewById(R.id.verladestellen_liste);
for (final DB_Place cn : placeList) {
final LinearLayout row = new LinearLayout(this);
row.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
Button place = new Button(this);
place.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
place.setText(cn.getName());
place.setId(cn.getID());
row.addView(place);
row.setId(cn.getID());
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) place.getLayoutParams();
params.weight = 1.0f;
place.setLayoutParams(params);
place.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openMap(cn.getID());
}
});
layout.addView(row);
}
}
public void openMap(int view) {
Intent intent = new Intent(UI_Verladestellen.this, UI_MainActivity.class);
intent.putExtra("findLocation", 1);
startActivity(intent);
}
}
And this is the getIntent of my onCreate method in UI_MainActivity:
int i = getIntent().getIntExtra("findlocation", 999);
if(i == 1){
findLocation(i);
}
As I edited into my earlier comment, i cant see where my Button-ID is recieved. At first i thought i would be my ID, but that wouldnt work, since The Button ID can be every number from 1 to n.

You can achieve this with an Intent e.g.
Intent i = new Intent(BaseActivity.this, YourSecondActivity.class);
intent.putExtra("METHOD_TO_CALL", 1);
startActivity(i);
and in your onCreate() method of the starting Activity you check for it.
#Override
public void onCreate(Bundle savedInstanceState) {
int i = getIntent().getIntExtra("METHOD_TO_CALL", 999);
if(i == 1){
callMethod(i);
}
EDIT:
//The method to start the other activity
public void openMap(View view) {
Intent intent = new Intent(this, UI_MainActivity.class);
intent.putExtra("METHOD_TO_CALL", 1); // the 1 is a example, put your ID here
startActivity(intent);
}

Step #1: Use putExtra() to add your ID value to the Intent that you use with startActivity()
Step #2: In the other activity, call getIntent() in onCreate() to retrieve the Intent used to create the activity instance. Call get...Extra() (where ... depends on the data type) to retrieve your ID value. If the ID value exists, call your findLocation() method.

It depends on how you want it to work. If you only want it to execute when the activity is created (when it starts or screen rotates) then call the method within the activities onCreate method. If you want it called whenever the user returns to that activity which can include them leaving the app and coming back to it sometime later then onResume would be a better spot for it. Calling the method from either should work as you hope though.
I also recommend looking over the Activity lifecycle as that will help you a lot in the future.

Getting text of buttons from an Activity and setting it as text in Text View in other Activity

I m working on a project i have two categories Cricketers and Animals on one activity as Button and a Text View on other activity i want to change the text of Text View when ever i presses the Button i.e If Cricketer then set text to cricketer same goes for animal.
OnClick Listner for both buttons: On Activity 1
public void onClickcricketer(View view){
Intent i = new Intent(this,offlineQuestionsession.class);
final Button b = (Button)findViewById(R.id.btncricket);
String crickettext = b.getText().toString();
i.putExtra("Cricket",crickettext);
startActivity(i);
}
public void onClickanimal(View view){
Intent i = new Intent(this,offlineQuestionsession.class);
final Button b = (Button)findViewById(R.id.btnanimal);
String animaltext = b.getText().toString();
i.putExtra("Animal",animaltext);
startActivity(i);
}
Code on Activity 2:
Bundle cricketData = getIntent().getExtras();
if (cricketData == null){
return;
}
String Cricket = cricketData.getString("Cricket");
final TextView c = (TextView)findViewById(R.id.txtCategryShow);
c.setText(Cricket);
Bundle AnimalData = getIntent().getExtras();
if (AnimalData == null){
return;
}
String Animal = AnimalData.getString("Animal");
final TextView a = (TextView)findViewById(R.id.txtCategryShow);
a.setText(Animal);
This method just show animal text in Text view.. when i click Crcketer button it shows nothing

First perform an onClick method:
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String toExtra = "" + btn.getText();
Intent i = new Intent(this,NextActivity.class);
i.putExtra("key",toExtra);
}
});
then in the new Activity OnCreate method add:
Intent i = getIntent();
String fromExtra = intent.getStringExtra("key");
and finally setText to your TextView:
txt.setText(fromExtra)

It is doing correct, see your code again, On same TextView you are setting text Animal which is null in case of clicking cricket ..
Try this in second activity:
String Cricket = getIntent().getStringExtra("KEY");
final TextView c = (TextView)findViewById(R.id.txtCategryShow);
c.setText(Cricket);
And make your methods like this:
public void onClickcricketer(View view){
Intent i = new Intent(this,YourNewActivity.class);
final Button b = (Button)findViewById(R.id.txv_cricket);
String crickettext = b.getText().toString();
i.putExtra("KEY",crickettext);
startActivity(i);
}
public void onClickanimal(View view){
Intent i = new Intent(this,YourNewActivity.class);
final Button b = (Button)findViewById(R.id.txv_animal);
String animaltext = b.getText().toString();
i.putExtra("KEY", animaltext);
startActivity(i);
}