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我有一张图片，我想在 Android 应用程序中反映该图片，下面是源代码。我找到了一个示例代码 

      ImageView imageView = (ImageView) findViewById(R.id.image1);                
      imageView.setImageResource(imageIDs[position]);

    //The gap we want between the reflection and the original image
      final int reflectionGap = 4;

      //Get you bit map from drawable folder
      Bitmap originalImage = BitmapFactory.decodeResource(getResources(), 
              imageIDs[position]);

      int width = originalImage.getWidth();
      int height = originalImage.getHeight();


      //This will not scale but will flip on the Y axis
      Matrix matrix = new Matrix();
      matrix.preScale(1, -1);

      //Create a Bitmap with the flip matix applied to it.
      //We only want the bottom half of the image
      Bitmap reflectionImage ;
      if(isVertical)
          reflectionImage= Bitmap.createBitmap(originalImage, 0, height/2, width, height/2, matrix, false);
      else
          reflectionImage= Bitmap.createBitmap(originalImage, width/2, 0, width/2, height, matrix, false);

      //Create a new bitmap with same width but taller to fit reflection
      Bitmap bitmapWithReflection;
      if(isVertical)
          bitmapWithReflection = Bitmap.createBitmap(width 
        , (height + height/2), Config.ARGB_8888);
      else
          bitmapWithReflection = Bitmap.createBitmap(width +width/2
                    , height, Config.ARGB_8888);

     //Create a new Canvas with the bitmap that's big enough for
     //the image plus gap plus reflection
     Canvas canvas = new Canvas(bitmapWithReflection);
     //Draw in the original image
     canvas.drawBitmap(originalImage, 0, 0, null);
     //Draw in the gap
     Paint deafaultPaint = new Paint();
     if(isVertical)
     canvas.drawRect(0, height, width, height + reflectionGap, deafaultPaint);
     else
         canvas.drawRect(width, 0, width+reflectionGap, height, deafaultPaint);
     //Draw in the reflection
     if(isVertical)
     canvas.drawBitmap(reflectionImage,0, height + reflectionGap, null);
     else
         canvas.drawBitmap(reflectionImage,width + reflectionGap,0 , null);

     //Create a shader that is a linear gradient that covers the reflection
     Paint paint = new Paint(); 
     LinearGradient shader;
     if(isVertical)
     shader = new LinearGradient(0, originalImage.getHeight(), 0, 
       bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, 
       TileMode.CLAMP); 
     else
         shader = new LinearGradient(originalImage.getWidth(),0,  
                   bitmapWithReflection.getWidth() + reflectionGap,0,  0x70ffffff, 0x00ffffff,
                   TileMode.CLAMP); 
     //Set the paint to use this shader (linear gradient)
     paint.setShader(shader); 
     //Set the Transfer mode to be porter duff and destination in
     paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
     //Draw a rectangle using the paint with our linear gradient
     if(isVertical)
     canvas.drawRect(0, height, width, 
       bitmapWithReflection.getHeight() + reflectionGap, paint); 
     else
         canvas.drawRect(width, 0, bitmapWithReflection.getWidth() + reflectionGap, 
                   height, paint); 

     //Create an Image view and add our bitmap with reflection to it
     //ImageView imageView = new ImageView(this);
     imageView.setImageBitmap(bitmapWithReflection);`

当我在图像底部给出 isVertical 值 = true 时，此示例可以正常工作，但我也想在图像右侧使用反射效果，因为我认为它在横向模式下会更好。但它不像我想要的那样工作。它显示反射侧上下颠倒。我的错误是什么？谢谢。

4

1 回答 1

1

你的矩阵必须改变：

if (isVertical) {
  matrix.preScale(1, -1);
  reflectionImage= Bitmap.createBitmap(originalImage, 0, height/2, width, height/2, matrix, false);
}
else {
  matrix.preScale(-1, 1);
  reflectionImage= Bitmap.createBitmap(originalImage, width/2, 0, width/2, height, matrix, false);

}
于 2012-04-20T18:48:43.183 回答