Android：从RECT构造位图

Question

我们可以通过矩形构造位图吗？

我在矩形中绘制位图，并希望在位图图像上绘制的笔画成为图像的一部分。

我想知道是否可以从Rect构造位图，以便新位图将旧图像和笔画作为单个图像。

谢谢

Answer 1

你总是可以采取一个画布，以帮助您创建一个已解码的位图，你所希望的方式：

Bitmap originalBmp = null;//Here goes original Bitmap... 
ImageView img = null;//Any imageview holder you are using... 
Bitmap modifiedBmp = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);//Configure with your proper size and color 
Canvas canvas = new Canvas(modifiedBmp); 

//At this point the modified bitmap has the original one, starting from here, you can add any overlay you want... 
canvas.drawBitmap(originalBmp, 0, 0, new Paint()); 

//And do all the other modifications you want here... 
canvas.drawLines(new float[]{}, null); 
canvas.drawCircle(x, y, radius, null); 

//At this point the modified bitmap will have anything you added 
img.setImageBitmap(modifiedBmp); 

// IF YOU ARE OVERRIDING ONDRAW METHOD 
public void onDraw(Canvas canvas){ 

    //Here DO your DRAW BITMAP NOTE: paint must be already created... 
    canvas.drawBitmap(bt, 0, 0, paint); 

    paint.setColor(Color.BLACK); 
    paint.setStrokeWidth(3); 
    canvas.drawRect(30, 30, 80, 80, paint); 

    super.onDraw(canvas); 
} 

商祺！

Answer 2

是的，你可以，使用画布，你可以在你的旧bimtap上画一些东西。

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()); 

       paint.setAntiAlias(true); 
       canvas.drawARGB(0, 0, 0, 0); 
       paint.setColor(color); 
        // do some canvas drawing 
       canvas.drawBitmap(bitmap, rect, rect, paint);