如何在每次单击按钮时在 imageview 中旋转图像?

This is java code.I am getting image from image gallery.I have one Button and one ImageView. It is rotating only one time.When I again click button it is not rotating image.

public class EditActivity extends ActionBarActivity
{
private Button rotate;
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_edit);
    rotate=(Button)findViewById(R.id.btn_rotate1);
    imageView = (ImageView) findViewById(R.id.selectedImage);
    String path = getIntent().getExtras().getString("path");
    final Bitmap bitmap = BitmapFactory.decodeFile(path);
    imageView.setScaleType(ImageView.ScaleType.FIT_XY);
    imageView.setImageBitmap(Bitmap.createScaledBitmap(bitmap, 510, 500,
            false));
    rotate.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
          {                  
            imageView.setRotation(90);


        }
    });



}

推荐答案

将你的 onClick() 方法更改为

@Override
public void onClick(View v)
{                  
    imageView.setRotation(imageView.getRotation() + 90);
}

注意，docs 说什么

设置视图围绕枢轴点旋转的度数.增加值会导致顺时针旋转.

private int mCurrRotation = 0; // takes the place of getRotation()

mCurrRotation %= 360;
float fromRotation = mCurrRotation;
float toRotation = mCurrRotation += 90;

final RotateAnimation rotateAnim = new RotateAnimation(
        fromRotation, toRotation, imageview.getWidth()/2, imageView.getHeight()/2);

rotateAnim.setDuration(1000); // Use 0 ms to rotate instantly 
rotateAnim.setFillAfter(true); // Must be true or the animation will reset

imageView.startAnimation(rotateAnim);