Question

我想在TextView中旋转drawableLeft。

我试过这段代码：

Drawable result = rotate(degree);
setCompoundDrawables(result, null, null, null);

private Drawable rotate(int degree)
{
    Bitmap iconBitmap = ((BitmapDrawable)originalDrawable).getBitmap();

    Matrix matrix = new Matrix();
    matrix.postRotate(degree);
    Bitmap targetBitmap = Bitmap.createBitmap(iconBitmap, 0, 0, iconBitmap.getWidth(), iconBitmap.getHeight(), matrix, true);

    return new BitmapDrawable(getResources(), targetBitmap);
}

但是它给了我左侧drawable的位置一个空白区域。

实际上，即使这个最简单的代码也会给出空白：

Bitmap iconBitmap = ((BitmapDrawable)originalDrawable).getBitmap();
Drawable result = new BitmapDrawable(getResources(), iconBitmap);
setCompoundDrawables(result, null, null, null);

这个很好用：

 setCompoundDrawables(originalDrawable, null, null, null);

Answer 1

根据the docs，如果您想设置drawableLeft，请拨打setCompoundDrawablesWithIntrinsicBounds (int left, int top, int right, int bottom)。调用setCompoundDrawables（）只有在Drawable上调用setBounds（）时才有效，这可能就是你的originalDrawable可以工作的原因。

所以将代码更改为：

Drawable result = rotate(degree);
setCompoundDrawablesWithIntrinsicBounds(result, null, null, null);

Answer 2

您不能只将Drawable“投射”到BitmapDrawable

要将Drawable转换为Bitmap，您必须“绘制”它，如下所示：

Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap); 
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);

见这里的帖子：

How to convert a Drawable to a Bitmap?

将旋转绘制设置为TextView的drawableLeft

2 个答案: