通過Seekbar縮放位圖

Question

我正在使用seekbar縮放圖像。圖像被縮放到一個特定的大小，無論您採用seekbar並將其縮放爲一次，下一次您更改seekbar的進度時，圖像保持相同的更改大小。我想隨着seekbar進度的增加或減少而動態縮放它。

搜索欄的代碼片段

seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { 

     @Override 
     public void onStopTrackingTouch(SeekBar arg0) { 
      // TODO Auto-generated method stub 

     } 

     @Override 
     public void onStartTrackingTouch(SeekBar arg0) { 
      // TODO Auto-generated method stub 

     } 

     @Override 
     public void onProgressChanged(SeekBar seekBar, int progresValue, 
       boolean fromUser) { 
      // TODO Auto-generated method stub 
      Log.i("Test", "Progress value = " + Integer.toString(progresValue)); 
      Log.i("Test", "Image width = " + Integer.toString(width)); 
      Log.i("Test", "Image height = " + Integer.toString(height)); 

      scaleImage(image, width, height); 
     } 
    }); 

功能縮放圖像

public void scaleImage(Bitmap bitmap, int w, int h) { 

    // Get current dimensions AND the desired bounding box 
    int bounding = dpToPx(150); 
    Log.i("Test", "original width = " + Integer.toString(w)); 
    Log.i("Test", "original height = " + Integer.toString(h)); 
    Log.i("Test", "bounding = " + Integer.toString(bounding)); 

    // Determine how much to scale: the dimension requiring less scaling is 
    // closer to the its side. This way the image always stays inside your 
    // bounding box AND either x/y axis touches it. 
    float xScale = ((float) bounding)/w; 
    float yScale = ((float) bounding)/h; 
    float scale = (xScale <= yScale) ? xScale : yScale; 
    Log.i("Test", "xScale = " + Float.toString(xScale)); 
    Log.i("Test", "yScale = " + Float.toString(yScale)); 
    Log.i("Test", "scale = " + Float.toString(scale)); 

    // Create a matrix for the scaling and add the scaling data 
    Matrix matrix = new Matrix(); 
    matrix.postScale(scale, scale); 

    // Create a new bitmap and convert it to a format understood by the 
    // ImageView 
    Bitmap scaledBitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, 
      true); 
    sWidth = scaledBitmap.getWidth(); // re-use 
    sHeight = scaledBitmap.getHeight(); // re-use 
    @SuppressWarnings("deprecation") 
    BitmapDrawable result = new BitmapDrawable(scaledBitmap); 
    Log.i("Test", "scaled width = " + Integer.toString(sWidth)); 
    Log.i("Test", "scaled height = " + Integer.toString(sHeight)); 
    qrImage.setImageDrawable(result); 

} 

功能，使邊框下面的代碼

private int dpToPx(int dp) { 
    float density = getActivity().getApplicationContext().getResources() 
      .getDisplayMetrics().density; 
    return Math.round((float) dp * density); 
} 

Answer 1

使用使用搜索條

調整圖片大小

public class MyActivity extends Activity { 

private static final int WIDTH_SCALE_RATIO = 10; 
private static final int HEIGHT_SCALE_RATIO = 10; 
private int previousProcess = 0; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    final ImageView img = (ImageView) findViewById(R.id.img); 
    ((SeekBar) findViewById(R.id.seekBar)) 
      .setOnSeekBarChangeListener(new OnSeekBarChangeListener() { 
       @Override 
       public void onStopTrackingTouch(SeekBar arg0) { 
       } 

       @Override 
       public void onStartTrackingTouch(SeekBar arg0) { 
       } 

       @Override 
       public void onProgressChanged(SeekBar seekBar, 
         int progresValue, boolean fromUser) { 
        int diff = progresValue - previousProcess; 
        scaleImage(img, diff); 
        previousProcess = progresValue; 
       } 
      }); 
} 

public void scaleImage(ImageView img, int scale) { 
    Bitmap bitmap = ((BitmapDrawable) img.getDrawable()).getBitmap(); 
    float width = bitmap.getWidth(); 
    float height = bitmap.getHeight(); 
    width += scale * WIDTH_SCALE_RATIO; 
    height += scale * HEIGHT_SCALE_RATIO; 
    bitmap = Bitmap.createScaledBitmap(bitmap, (int) width, (int) height, 
      true); 
    img.setImageBitmap(bitmap); 
} 
}