Android Button Onclick

Question

OK I\'m new to android dev\'s and Java, so I\'m having problems with on click method here\'s my code. I know I\'ve gotta be close, thanks in advance. All I want my button to

Answer 1

You need to make the same method name both in layout XML and java code.

If you use android:onClick="setLogin" then you need to make a method with the same name, setLogin:

// Please be noted that you need to add the "View v" parameter
public void setLogin(View v) {

}

ADVICE:
Do not mix layout with code by using android:onClick tag in your XML. Instead, move the click method to your class with OnClickListener method like:

Button button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
  public void onClick(View v) {
    // TODO Auto-generated method stub
  }
 });

Make a layout just for layout and no more. It will save your precious time when you need to refactoring for Supporting Multiple Screens.

Answer 2

Method 1:

public void onClick(View v) {
          Intent i = new Intent(currentActivity.this, SecondActivity.class);
         startActivty(i);
        }

Method 2:

Button button = (Button) findViewById(R.id.mybutton);
 button.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
         Toast.makeText(this, "Button Clicked", Toast.LENGTH_LONG).show();

    }
 });

Answer 3

Here is some sample code of how to add a button named Add. You should declare the variable as a member variable, and the naming convention for member variables is to start with the letter "m".

Hit Alt+Enter on the classes to add the missing references.

Add this to your activity_main.xml:

 <Button
        android:id="@+id/buttonAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="ADD"
     />

Add this to your MainActivity.java:

public class MainActivity extends AppCompatActivity {

    Button mButtonAdd; 

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButtonAdd = findViewById(R.id.buttonAdd);

        mButtonAdd.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                // do something here
            }
        });
    }
}

Answer 4

If you write like this in Button tag in xml file : android:onClick="setLogin" then

Do like this:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<Button
    android:id="@+id/button1"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/btn"
    android:onClick="onClickBtn" />

</LinearLayout>

and in Code part:

public class StartUpActivity extends Activity 
{
    public void onCreate(Bundle savedInstanceState) 
    {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);    
    }

    public void onClickBtn(View v)
    {
        Toast.makeText(this, "Clicked on Button", Toast.LENGTH_LONG).show();
    } 
}

and no need all this:

 Button button = (Button) findViewById(R.id.button1);
 button.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
        // TODO Auto-generated method stub

    }
 });

Check it once;

Answer 5

Use Layout inflater method in your button click. it will change your current .xml to targeted .xml file. Google for layout inflater code.

Answer 6

There are two solutions for this are :-

(1) do not put onClick in xml

(2) remove

button.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
            // TODO Auto-generated method stub
    }
});

and put

public void setLogin(View v) {
    // Your code here
}