Android how to rotate Image

This tutorial will show you how to rotate image.

main.xml

RotateImage.java

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class RotateImage extends Activity {
 private ImageView img;
 private Button btn;
 private Bitmap bmp;
 private int r = 0;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        img=(ImageView)findViewById(R.id.ImageView01);
        btn = (Button)findViewById(R.id.btn);
        bmp = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
        btn.setOnClickListener(new View.OnClickListener() {
   
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    r += 90;
    if(r >= 360) r=0;
    setRotation(r);
   }
  });
        
    }
    
    private void setRotation(int rotate){
      // Getting width & height of the given image.
        int w = bmp.getWidth();
        int h = bmp.getHeight();
        // Setting post rotate to 90
        Matrix mtx = new Matrix();
        mtx.postRotate(rotate);
        // Rotating Bitmap
        Bitmap rotatedBMP = Bitmap.createBitmap(bmp, 0, 0, w, h, mtx, true);
        BitmapDrawable bmd = new BitmapDrawable(rotatedBMP);

        img.setImageDrawable(bmd);
    }
}