Question

我有一个拥有自己背景的ImageView。我试图在一个点画圆，但圆的位置不对。例如，我在0,0画圆，但它不在背景的左上角。我的代码有什么问题？

此外我需要位图大小与imageview相同但是当我在应用程序中实现imageView.getWidth或.getHeight来创建位图时，应用程序将崩溃！如何设置位图的大小与Imageview的大小相同？！感谢

    private void createBitMap() {
    ImageView imageView = (ImageView) findViewById(R.id.imageView);
    Bitmap bitMap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);  //creates bmp
    bitMap = bitMap.copy(bitMap.getConfig(), true);     //lets bmp to be mutable
    Canvas canvas = new Canvas(bitMap);                 //draw a canvas in defined bmp

    Paint paint = new Paint();                          //define paint and paint color
    paint.setColor(Color.RED);
    paint.setStyle(Style.FILL_AND_STROKE);
    //paint.setStrokeWidth(0.5f);
    paint.setAntiAlias(true);                           //smooth edges

    imageView.setImageBitmap(bitMap);
    //changed set image resource to set image background resource
    imageView.setBackgroundResource(R.drawable.map);
    canvas.drawCircle(0, 0, 3, paint);
    //invalidate to update bitmap in imageview
    imageView.invalidate();
}

Answer 1

希望您没有在xml布局中向imageView添加任何填充。 {你的代码看起来不错}

要拉伸图像以匹配您的imageView，请将此代码添加到布局文件的ImageView中：

android:scaleType="fitXY"

Answer 2

试试这个......

    private void createBitMap() {
        ImageView imageView = (ImageView) findViewById(R.id.imageView);
        // this gives a mutable bitmap. no need to mutate it again...
        Bitmap bitMap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888); 

        Canvas canvas = new Canvas(bitMap); // draw a canvas in defined bmp

        Paint paint = new Paint(); // define paint and paint color
        paint.setColor(Color.RED);
        paint.setStyle(Paint.Style.FILL_AND_STROKE);
        // paint.setStrokeWidth(0.5f);
        paint.setAntiAlias(true); // smooth edges
        canvas.drawCircle(0, 0, 3, paint);

        imageView.setImageBitmap(bitMap);
        // changed set image resource to set image background resource
        imageView.setBackgroundResource(R.drawable.map);
    }

为什么圆圈被绘制在错误的地方

2 个答案: