如何将以编程方式生成的位图放置在视图中？

Question

我像这样以编程方式生成了一个圆形位图：

private Bitmap drawDotCircle() {
        int circleSize = 100;
        circleBitmap = Bitmap.createBitmap(
                circleSize,
                circleSize,
                Bitmap.Config.ARGB_8888
        );

        canvas = new Canvas(circleBitmap);
        CanvasRadius = Math.min(canvas.getWidth(), canvas.getHeight() / 2);

        // Create a Paint object used to paint the circle
        paint = new Paint();
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.RED);
        paint.setAntiAlias(true);

        canvas.drawCircle(
                canvas.getWidth() / 2,
                canvas.getHeight() / 2,
                CanvasRadius - CanvasPadding,
                paint
        );

        return circleBitmap;
    }

我想把它放在我计算出的绝对 X 和 Y 上；假设它位于屏幕的绝对中心，如下所示：

int dotX =getResources().getDisplayMetrics().widthPixels / 2;
int dotY = getResources().getDisplayMetrics().heightPixels / 2;

如何确保圆在视图中居中？我试过下面的代码，但是由于某种原因，圆圈总是偏离中心：

        RelativeLayout.LayoutParams layoutParams =
                new RelativeLayout.LayoutParams(circleDot.getHeight(), circleDot.getHeight());

// Setting position of our ImageView
        layoutParams.leftMargin = dotX;
        layoutParams.topMargin = dotY;

// Finally Adding the imageView to RelativeLayout and its position
        relativeLayout.addView(dotView, layoutParams);

Answer 1

leftMargin 应该是 dotX - imageWidth/2 topMargin 应该是 dotY - imageHeight/2

试试看

如何将以编程方式生成的位图放置在视图中？

How do I place a programatically generated bitmap in a View?

java

android

view

bitmap

android-relativelayout