如何以编程方式完全围绕位图添加填充？

Question

我正在尝试以编程方式向位图添加填充，但是，当我将填充添加到顶部时，它会从底部移除。当我将它添加到底部时，它会从顶部移除。

在顶部添加内边距

Bitmap backgroundBitmap = ((BitmapDrawable) backgroundDrawable).getBitmap();


            int padding = 60;

            int positionLeft = 0;
            int positionTop = 0;
            Bitmap mainBitmap = Bitmap.createBitmap(
                    backgroundBitmap.getWidth(), //Adding top padding here
                    backgroundBitmap.getHeight() + padding,
                    Bitmap.Config.ARGB_8888
            );
            Canvas canvas = new Canvas(mainBitmap);
            canvas.drawBitmap(
                    backgroundBitmap,
                    positionLeft + padding,
                    positionTop + padding,
                    null
            );

向底部添加填充会移除顶部填充

 Bitmap backgroundBitmap = ((BitmapDrawable) backgroundDrawable).getBitmap();


            int padding = 60;

            int positionLeft = 0;
            int positionTop = 0;
            Bitmap mainBitmap = Bitmap.createBitmap(
                    backgroundBitmap.getWidth(),
                    backgroundBitmap.getHeight() + padding,
                    Bitmap.Config.ARGB_8888
            );
            Canvas canvas = new Canvas(mainBitmap);
            canvas.drawBitmap(
                    backgroundBitmap,
                    positionLeft + padding,
                    positionTop, //Adding bottom padding here
                    null
            );

想不通

如何向我的 backgroundBitmap 位图的所有 4 个边添加填充？

编辑 1:____________________________________________

我也尝试过这个解决方案：

为位图添加边框，但它只是在顶部和左侧添加边框。不包括底部和右侧

private Bitmap addWhiteBorder(Bitmap bmp, int borderSize) {
    Bitmap bmpWithBorder = Bitmap.createBitmap(bmp.getWidth() + borderSize * 2, bmp.getHeight() + borderSize * 2, bmp.getConfig());
    Canvas canvas = new Canvas(bmpWithBorder);
    canvas.drawColor(Color.BLUE);
    canvas.drawBitmap(bmp, borderSize, borderSize, null);
    return bmpWithBorder;
}

Bitmap backgroundBitmap = ((BitmapDrawable) backgroundDrawable).getBitmap();


            int padding = 60;

            int positionLeft = 0;
            int positionTop = 0;
            Bitmap mainBitmap = Bitmap.createBitmap(
                    backgroundBitmap.getWidth(),
                    backgroundBitmap.getHeight(),
                    Bitmap.Config.ARGB_8888
            );
            Canvas canvas = new Canvas(mainBitmap);
            canvas.drawBitmap(
                    addWhiteBorder(backgroundBitmap, padding),
                    positionLeft,
                    positionTop,
                    null
            );

Answer 1

这可能对您有帮助，也可能对您没有帮助，但不要填充位图，将其添加到视图中的容器，如线性布局，然后填充线性布局。对付起来应该会容易很多。

int left = (canvas.getWidth()-mainBitmap.getWidth())/2;
int top = (canvas.getHeight()-mainBitmap.getHeight())/2;
canvas.drawBitmap(mainBitmap, left, top, null);

这应该使位图相对于 canvas 居中。如果你需要更多信息，我是从这里得到的 How to align the canvas object to center of the screen?

Answer 2

主要问题是我的主位图中没有足够的填充 space

            Bitmap backgroundBitmap = ((BitmapDrawable) backgroundDrawable).getBitmap();
            Bitmap appLogoBitmap = ((BitmapDrawable) appLogoDrawable).getBitmap();

            int padding = 60;

            int positionLeft = 0;
            int positionTop = 0;
            Bitmap mainBitmap = Bitmap.createBitmap(
                    backgroundBitmap.getWidth() + (padding * 2), //Adding the * 2 helped display the padding
                    backgroundBitmap.getHeight()  + (padding * 2),
                    Bitmap.Config.ARGB_8888
            );
            Canvas canvas = new Canvas(mainBitmap);
            canvas.drawBitmap(
                    addWhiteBorder(backgroundBitmap, padding),
                    positionLeft,
                    positionTop,
                    null
            );

以及添加填充的函数：

private Bitmap addWhiteBorder(Bitmap bmp, int borderSize) {
        Bitmap bmpWithBorder = Bitmap.createBitmap(bmp.getWidth() + borderSize * 2, bmp.getHeight() + borderSize * 2, bmp.getConfig());
        Canvas canvas = new Canvas(bmpWithBorder);
        canvas.drawColor(Color.parseColor("#63A4FF"));
        canvas.drawBitmap(bmp, borderSize, borderSize, null);
        return bmpWithBorder;
    }

如何以编程方式完全围绕位图添加填充？

How to add padding completely around a bitmap programmatically?

android

android-canvas

android-bitmap