Android 旋轉圖片

    import android.app.Activity;

    import android.graphics.Bitmap;

    import android.graphics.Matrix;

    import android.graphics.drawable.BitmapDrawable;

    import android.os.Bundle;

    import android.view.View;

    import android.view.View.OnClickListener;

    import android.view.animation.Animation;

    import android.view.animation.Animation.AnimationListener;

    import android.view.animation.RotateAnimation;

    import android.widget.Button;

    import android.widget.ImageView;

    import android.widget.LinearLayout;


public class RotateBitmapActivity extends Activity {  

    Button btnRotate1, btnRotate2;  
    ImageView ivBitmap;  

    //逆時針轉45度  
    RotateAnimation rotateAnimation = new RotateAnimation(0, -45, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);  

    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        // TODO Auto-generated method stub  
        super.onCreate(savedInstanceState);  
        setTitle("旋轉圖片");  
        setContentView(R.layout.rorate_bitmap);  
        btnRotate1 = (Button) findViewById(R.id.btn_rorate);  
        btnRotate2 = (Button) findViewById(R.id.btn_rorate_anim);  
        ivBitmap = (ImageView) findViewById(R.id.iv_bitmap);  

        btnRotate1.setOnClickListener(new OnClickListener() {  

            @Override  
            public void onClick(View v) {  
                // TODO Auto-generated method stub  
                rotateBitmap1();  
            }  
        });  
        btnRotate2.setOnClickListener(new OnClickListener() {  

            @Override  
            public void onClick(View v) {  
                // TODO Auto-generated method stub  
                rotateBitmap2();  
            }  
        });  
    }  
    /** 
     * 使用矩陣對象 旋轉 
     */  
    private void rotateBitmap1() {  
        LinearLayout linLayout = new LinearLayout(this);   
        BitmapDrawable bitmapDrawable = (BitmapDrawable) ivBitmap.getDrawable();  
        //獲取這個圖片的寬和高  
        int width = bitmapDrawable.getBitmap().getWidth();   
        int height = bitmapDrawable.getBitmap().getHeight();   
        //定義預轉換成的圖片的寬度和高度  
        int newWidth = getWindow().getWindowManager().getDefaultDisplay().getWidth() / 2;   
        int newHeight = getWindow().getWindowManager().getDefaultDisplay().getHeight() / 2;  
        //計算縮放率，新尺寸除原始尺寸  
        float scaleWidth = ((float) newWidth) / width;   
        float scaleHeight = ((float) newHeight) / height;   
        // 創建操作圖片用的matrix對象  
        Matrix matrix = new Matrix();   
        // 縮放圖片動作  
        matrix.postScale(scaleWidth, scaleHeight);   
        //旋轉圖片 動作  
        matrix.postRotate(90);   
        // 創建新的圖片  
        Bitmap resizedBitmap = Bitmap.createBitmap(bitmapDrawable.getBitmap(), 0, 0, width, height, matrix, true);   

        ivBitmap.setImageBitmap(resizedBitmap);  
    }  

    /** 
     * 通過動畫方式旋轉，實際位置沒有改變，當再次運行該函數，圖像還是從原來的位置開始轉動 
     */  
    private void rotateBitmap2() {  

        rotateAnimation.setDuration(1000);  
        ivBitmap.startAnimation(rotateAnimation);  

        rotateAnimation.setAnimationListener(new AnimationListener() {  

            @Override  
            public void onAnimationStart(Animation animation) {  
                // TODO Auto-generated method stub  

            }  

            @Override  
            public void onAnimationRepeat(Animation animation) {  
                // TODO Auto-generated method stub  

            }  

            @Override  
            public void onAnimationEnd(Animation animation) {  
                // TODO Auto-generated method stub  
                rotateAnimation.setFillAfter(true);//動畫后的效果固定下來，實際圖片位置沒有改變  
                //逆時針轉45度  坐標點算不好，  
//              ivBitmap.layout(l, t, r, b);  
            }  
        });  

    }  


}  </pre>