转换Bitmap对象

Posted 2020-08-22 Yi米阳光

把一个View转换bitmap对象

1 public static Bitmap getViewBitmap(View view) {
2         view.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
3                 View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
4         view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
5         view.buildDrawingCache();
6         Bitmap bitmap = view.getDrawingCache();
7         return bitmap;
8     }

根据已有的Drawable创建一个新的Bitmap:

 1 private Bitmap bitmap;
 2 private void drawableToBitamp(Drawable drawable)
 3     {
 4         int w = drawable.getIntrinsicWidth();
 5         int h = drawable.getIntrinsicHeight();
 6         System.out.println("Drawable转Bitmap");
 7         Bitmap.Config config = 
 8                 drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
 9                         : Bitmap.Config.RGB_565;
10         bitmap = Bitmap.createBitmap(w,h,config);
11         //注意，下面三行代码要用到，否在在View或者surfaceview里的canvas.drawBitmap会看不到图
12         Canvas canvas = new Canvas(bitmap);   
13         drawable.setBounds(0, 0, w, h);   
14         drawable.draw(canvas);
15     }

直接从现有的Drawable中取出Bitmap:

1 private Bitmap bitmap;
2 
3 private void drawableToBitamp(Drawable drawable)
4     {
5         BitmapDrawable bd = (BitmapDrawable) drawable;
6         bitmap = bd.getBitmap();
7     }

Bitmap转Byte

1 private byte[] Bitmap2Bytes(Bitmap bm){
2 
3     ByteArrayOutputStream baos = new ByteArrayOutputStream();
4 
5     bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
6 
7     return baos.toByteArray();  
8  }

byte[] 转Bitmap:

 1 private Bitmap Bytes2Bimap(byte[] b){
 2 
 3                     if(b.length!=0){
 4 
 5                             return BitmapFactory.decodeByteArray(b, 0, b.length);
 6 
 7                     }
 8 
 9                     else {
10 
11                             return null;
12 
13                     }
14 
15           }