[Android] bitmap/drawable/byte的转换和获取圆角/倒影图片

draw转bitmap

public static Bitmap drawableToBitmap(Drawable drawable) {  
	Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
			drawable.getIntrinsicHeight(),
			drawable.getOpacity() != PixelFormat.OPAQUE ? 
					Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);  
			        Canvas canvas = new Canvas(bitmap);  
			        //canvas.setBitmap(bitmap);  
	drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());  
	drawable.draw(canvas);  
	return bitmap;  
}  

从资源中获取Bitmap

Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);

或者

Bitmap bmp = ((BitmapDrawable)getResources().getDrawable(R.drawable.show)).getBitmap();

Bitmap 转 byte[]

private byte[] Bitmap2Bytes(Bitmap bm){  
    ByteArrayOutputStream baos = new ByteArrayOutputStream();    
    bm.compress(Bitmap.CompressFormat.PNG, 100, baos);    
    return baos.toByteArray();  
}  

放大缩小图片:

//放大缩小图片    
public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){    
    int width = bitmap.getWidth();    
    int height = bitmap.getHeight();    
    Matrix matrix = new Matrix();    
    float scaleWidht = ((float)w / width);    
    float scaleHeight = ((float)h / height);    
    matrix.postScale(scaleWidht, scaleHeight);    
    Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);    
    return newbmp;    
} 

获得圆角图片的方法:

//获得圆角图片的方法    
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){    
           
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);    
    Canvas canvas = new Canvas(output);    
     
    final int color = 0xff424242;    
    final Paint paint = new Paint();    
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());    
    final RectF rectF = new RectF(rect);    
     
    paint.setAntiAlias(true);    
    canvas.drawARGB(0, 0, 0, 0);    
    paint.setColor(color);    
    canvas.drawRoundRect(rectF, roundPx, roundPx, paint);    
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));    
    canvas.drawBitmap(bitmap, rect, rect, paint);    
	     
    return output;    
} 

//获得带倒影的图片方法    
public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){    
    final int reflectionGap = 4;    
    int width = bitmap.getWidth();    
    int height = bitmap.getHeight();    
            
    Matrix matrix = new Matrix();    
    matrix.preScale(1, -1);    
            
    Bitmap reflectionImage = Bitmap.createBitmap(bitmap,0, height/2, width, height/2, matrix, false);   
              
    Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888);   
              
    Canvas canvas = new Canvas(bitmapWithReflection);    
    canvas.drawBitmap(bitmap, 0, 0, null);    
    Paint deafalutPaint = new Paint();    
    canvas.drawRect(0, height,width,height + reflectionGap,    
    deafalutPaint);    
       
    canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);    
             
    Paint paint = new Paint();    
    LinearGradient shader = new LinearGradient(0,    
    bitmap.getHeight(), 0, bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);   
     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    
    canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() + reflectionGap, paint);   
       
    return bitmapWithReflection;    
}