android - float 操作按钮边框颜色没有改变

Question

我使用以下代码更改了 Floating Action Button backgroundTintList 颜色:

fab.setBackgroundTintList(ColorStateList.valueOf(mResources.getColor(R.color.fab_color)));

但我最终在 API 4.4.2 上得到以下信息:

在 API 21 上一切看起来都很好 <= 但是在 API 21 以下，我对 FAB 有这个问题。

我正在以编程方式创建 FAB，如下所示:

    FloatingActionButton fab = new FloatingActionButton(this);
    CoordinatorLayout.LayoutParams layoutParams = new CoordinatorLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    fab.setLayoutParams(layoutParams);
    layoutParams.rightMargin = mResources.getDimensionPixelSize(R.dimen.activity_horizontal_margin);
    ((CoordinatorLayout) findViewById(R.id.coordinatorLayout)).addView(fab);

    CoordinatorLayout.LayoutParams p = (CoordinatorLayout.LayoutParams) fab.getLayoutParams();
    p.setAnchorId(R.id.appBarLayout);
    p.anchorGravity = Gravity.BOTTOM | Gravity.END;
    fab.setLayoutParams(p);
    fab.setVisibility(View.VISIBLE);
    fab.setBackgroundTintList(ColorStateList.valueOf(mResources.getColor(R.color.fab_color)));
    fab.setImageDrawable(getResources().getDrawable(R.drawable.ic_button));

我也正好被官方跑了source code对于 FloatingActionButton，我看到他们在这里实例化了一个 borderDrawable:

 @Override
void setBackgroundDrawable(Drawable originalBackground, ColorStateList backgroundTint,
        PorterDuff.Mode backgroundTintMode, int rippleColor, int borderWidth) {
    // Now we need to tint the original background with the tint
    mShapeDrawable = DrawableCompat.wrap(originalBackground.mutate());
    DrawableCompat.setTintList(mShapeDrawable, backgroundTint);
    if (backgroundTintMode != null) {
        DrawableCompat.setTintMode(mShapeDrawable, backgroundTintMode);
    }

    final Drawable rippleContent;
    if (borderWidth > 0) { // BORDER DRAWABLE RIGHT HERE!!
        mBorderDrawable = createBorderDrawable(borderWidth, backgroundTint);
        rippleContent = new LayerDrawable(new Drawable[]{mBorderDrawable, mShapeDrawable});
    } else {
        mBorderDrawable = null;
        rippleContent = mShapeDrawable;
    }

    mRippleDrawable = new RippleDrawable(ColorStateList.valueOf(rippleColor),
            rippleContent, null);

    mShadowViewDelegate.setBackgroundDrawable(mRippleDrawable);
    mShadowViewDelegate.setShadowPadding(0, 0, 0, 0);
}

Answer 1

我结束添加:

app:borderWidth="0dp"

这不会创建 borderDrawable 并且边框不可见。