将旋转的drawable设置为TextView的drawableLeft

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);
}

但它在左侧可绘制的地方给了我一个空白空间。

实际上，即使是最简单的代码也会出现空格：

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，如果你想设置drawableLeft，你应该调用setCompoundDrawablesWithIntrinsicBounds (int left, int top, int right, int bottom)。仅当在 Drawable 上调用 setBounds() 时调用 setCompoundDrawables() 才有效，这可能是您 originalDrawable 有效的原因。

所以把你的代码改成：

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

Answer 2

您不能只是将Drawable“转换”为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);

在此处查看帖子：

How to convert a Drawable to a Bitmap?