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我想像 Flipboard 一样为图像添加水印。

如您所见，文本添加在具有黑色透明背景的图像底部。我想做同样的事情。到目前为止，我已经设法在图像上写了文字，但我无法像上图一样让它的背景黑色透明。

到目前为止，这是我从这里找到的代码。

public Bitmap mark(Bitmap src, String watermark) {
    int w = src.getWidth();
    int h = src.getHeight();

    Shader shader = new LinearGradient(0, 0, 100, 0, Color.TRANSPARENT, Color.BLACK, TileMode.CLAMP);

    Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
    Canvas canvas = new Canvas(result);
    canvas.drawBitmap(src, 0, 0, null);
    Paint paint = new Paint();
    paint.setColor(Color.WHITE);
    paint.setTextSize(50);
    paint.setAntiAlias(true);
    paint.setShader(shader);
    paint.setUnderlineText(false);
    canvas.drawText(watermark, 10 , h-15, paint);

    return result;
}
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1 回答 1

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我认为它不需要渐变，您可以使用简单的颜色并使用 drawRect() 方法绘制它。

示例代码如下，我将黑色背景大小作为整个图像的 25%。

public Bitmap mark(Bitmap src, String watermark) {
    int w = src.getWidth();
    int h = src.getHeight();

    Paint bgPaint=new Paint();
    bgPaint.setColor(Color.parse("AA000000"));  //transparent black,change opacity by changing hex value "AA" between "00" and "FF"

    Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
    Canvas canvas = new Canvas(result);
    canvas.drawBitmap(src, 0, 0, null);
    Paint paint = new Paint();
    paint.setColor(Color.WHITE);
    paint.setTextSize(50);
    paint.setAntiAlias(true);
    paint.setUnderlineText(false);

    //should draw background first,order is important
    int left=0;
    int right=w;
    int bottom=h;
    int top=bottom-(h*.25);
    canvas.drawRect(left,top,right,bottom,bgPaint);

    canvas.drawText(watermark, 10 , h-15, paint);

return result;
}
于 2013-07-04T18:33:46.900 回答