Question

I have updated the alert dialog box format using my own layout xml.

In this customerized alert dialog box there are 2 buttons, one button is to save the data being input, another one is a cancel button.

How could I write for the CANCEL button such that when the user click it, just simply to DISMISS the dialog box?

   public OnClickListener NewRowButtonListener = new OnClickListener()
   {
      @Override
      public void onClick(View v) 
      {               
          AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
          builder.setView(getLayoutInflater().inflate(R.layout.custom_dialog_add, null));
          builder.create();

          AlertDialog Custom_dialog_add = builder.create();
          Custom_dialog_add.show(); // show the Dialog

          Button CancelButton = (Button) findViewById(R.id.CancelButton);
          CancelButton.setOnClickListener(new View.OnClickListener() {       
              @Override 
              public void onClick(View v) {Custom_dialog_add.cancel();}  //WRONG: Cannot refer to a non-final variable Custom_dialog_add inside an inner class defined in a different method
            });         
      } 
   };  

it is now revised as follows:

       public OnClickListener NewRowButtonListener = new OnClickListener() 
       { 
          @Override 
          public void onClick(View v)  
          { 
              AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this); 
              dialog.setView(getLayoutInflater().inflate(R.layout.custom_dialog_add, null)); 
              dialog.create(); 

               final AlertDialog test = dialog.create(); 
               test.show();

               Button close = (Button) findViewById(R.id.CancelButton); 
               close.setOnClickListener(new android.view.View.OnClickListener() { 
                   public void onClick(View v) { 
                       test.dismiss(); 
                   } 
               });
          }
       };

The Eclipse does not report bugs to the revised codings, but when simulated, it runs out a nullpointer exception. The logcat is as follows. How could such be solved?

09-28 20:15:19.505: E/AndroidRuntime(25847): FATAL EXCEPTION: main
09-28 20:15:19.505: E/AndroidRuntime(25847): java.lang.NullPointerException
09-28 20:15:19.505: E/AndroidRuntime(25847):    at com.pearappx.gamescore3.MainActivity$4.onClick(MainActivity.java:422)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.view.View.performClick(View.java:3627)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.view.View$PerformClick.run(View.java:14329)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.os.Handler.handleCallback(Handler.java:605)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.os.Handler.dispatchMessage(Handler.java:92)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.os.Looper.loop(Looper.java:137)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at android.app.ActivityThread.main(ActivityThread.java:4511)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at java.lang.reflect.Method.invokeNative(Native Method)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at java.lang.reflect.Method.invoke(Method.java:511)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:980)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)
09-28 20:15:19.505: E/AndroidRuntime(25847):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

Would this code snippet help you?

        LayoutInflater inflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.custom_layout, null);
        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        dialog.setTitle("dialog");
        dialog.setView(view);
        final AlertDialog test = dialog.create();


        Button close = (Button) view.findViewById(R.id.close_button);
        close.setOnClickListener(new android.view.View.OnClickListener() {
            public void onClick(View v) {
                test.dismiss();

            }
        });

Edit updated version:

    //Create new alert dialog
    AlertDialog.Builder dialog = new AlertDialog.Builder(this);
    //set title
    dialog.setTitle("title");
    //create the dialog in a final context
    final AlertDialog test = dialog.create();
    //inflate the custom layout in to a View object
    View view = getLayoutInflater().inflate(R.layout.custom_dialog_add, null);

    //find the Button object within the inflated view
    //                       ↓↓↓
    Button close = (Button) view.findViewById(R.id.CancelButton);
    //set the onClickListener
    close.setOnClickListener(new OnClickListener() { 
        public void onClick(View v) { 
            test.dismiss(); 
        } 
    });
    //show the dialog
    test.show();

Don’t forget to use the right imports!