PagerTabStrip正在裁剪图标

Question

这个设计要求在PagerTabStrip的标签上只有一个图标。

下面是XML：

<android.support.v4.view.PagerTabStrip
        android:id="@+id/tbstrp_album"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:foregroundGravity="bottom"
        android:padding="0dp"
        android:background="@color/offWhite">

下面是我在适配器中的getPageTitle：

@Override
public CharSequence getPageTitle(int position) {
    // This is "generic" string that we will use as the title to be replaced.
    String title = "title";

    Drawable myDrawable = oContext.getDrawable(R.drawable.alpha);

    // initiate the SpannableString builder
    SpannableStringBuilder spanBuilder = new SpannableStringBuilder(title); // space added before text for convenience

    // set the drawable's size...if it could be too big or too small for display
    myDrawable.setBounds(0, 0, 50, 50);

    // turn the Drawable into ImageSpan and align it along the baseline
    ImageSpan imageSpan = new ImageSpan(myDrawable, ImageSpan.ALIGN_BASELINE);

    // CRUCIAL: this is where we replace the "title" w/ the image
    // 0: we start from the beginning
    // title.length(): we are replacing the entire string
    // the last flag doesn't do anything in our case
    spanBuilder.setSpan(imageSpan, 0, title.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

    return spanBuilder;
}

输出如下所示：

​

​

是什么原因导致条带裁剪图像？谢谢!

Answer 1

事实证明这句话才是罪魁祸首：

myDrawable.setBounds(0，0，50，50)；

我把第二个参数"top“改成了30，图标没有被裁剪。

未回答的问题是still...why我是否必须为"top“参数指定值。