matrix.postRotate（90）在图像旋转

Question

我只能旋转图像一次，当我再次点击按钮时，图像冻结，不旋转。请帮帮我。

try{ 
    //Bitmap bMap; 

    //Get ImageView from layout xml file 
    img = (ImageView) findViewById(R.id.imageView01); 

    //Decode Image using Bitmap factory. 
    Bitmap bMap = BitmapFactory.decodeFile(selectedImagePath); 

    //Create object of new Matrix. 
    Matrix matrix = new Matrix(); 

    //set image rotation value to 90 degrees in matrix. 
    matrix.postRotate(90); 

    //Create bitmap with new values. 
    Bitmap bMapRotate = Bitmap.createBitmap(bMap, 0, 0, bMap.getWidth(), bMap.getHeight(), matrix, true); 

    //put rotated image in ImageView. 
    img.setImageBitmap(bMapRotate); 

    Context context = getApplicationContext(); 
    CharSequence text = "Image Rotated" ; 
    int duration = Toast.LENGTH_SHORT; 

    Toast toast = Toast.makeText(context, text, duration); 

    toast.show(); 

}catch (Exception e) {  
    e.printStackTrace(); 
    displayExceptionMessage(e.getMessage()); 
} 

Answer 1

试试这个

try { 
    //Bitmap bMap; 

    //Get ImageView from layout xml file 
    img = (ImageView) findViewById(R.id.imageView01); 

    //Decode Image using Bitmap factory. 
    //Bitmap bMap = BitmapFactory.decodeFile(selectedImagePath); 
    Bitmap bMap = Bitmap.createBitmap(img.getDrawingCache()); 

    //Create object of new Matrix. 
    Matrix matrix = new Matrix(); 

    //set image rotation value to 90 degrees in matrix. 
    matrix.postRotate(90); 
    matrix.postScale(0.5f, 0.5f); 

    int newWidth = bMap.getWidth()/2; 
    int newHeight = bMap.getHeight()/2; 

    //Create bitmap with new values. 
    Bitmap bMapRotate = Bitmap.createBitmap(bMap, 0, 0, newWidth, newHeight, matrix, true); 

    //put rotated image in ImageView. 
    img.setImageBitmap(bMapRotate); 

    Context context = getApplicationContext(); 
    CharSequence text = "Image Rotated" ; 
    int duration = Toast.LENGTH_SHORT; 

    Toast toast = Toast.makeText(context, text, duration); 

    toast.show(); 

} catch (Exception e) {  
    e.printStackTrace(); 
    displayExceptionMessage(e.getMessage()); 
} 

西隧我在我们的代码所做的是我已经创建了从ImageView的旋转的位图。

希望这有助于..