How to make a ProgressBar stay in the center of screen despite scrolling

问题

I have a ProgressBar in a ScrollView, and I'd like it to stay centered vertically despite the user scrolling down or up. However, I'm not sure how to accomplish this.

Here's the code that I have, simple as it is. I have an indeterminate ProgressBar:

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/ocr_scroll_view"
android:layout_width="match_parent"
android:layout_height="fill_parent">

    <RelativeLayout android:id="@+id/image_holder"
    android:layout_gravity="end"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" >

        <ImageView android:id="@+id/image"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

        <ProgressBar android:id="@+id/progressBar1"
        style="?android:attr/progressBarStyleLarge"
        android:visibility="gone"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

And I call it as such:

    spinningProgressBar = (ProgressBar)findViewById(R.id.progressBar1);
    spinningProgressBar.setIndeterminate(true);
    spinningProgressBar.setVisibility(View.GONE);

Setting its visibility at the appropriate times.

All suggestions very much appreciated.

回答1:

Put it outside of the ScrollView. Just have the ScrollView and the ProgressBar overlap.

You can read about how to overlap views here: Overlapping Views in Android

There's a couple of ways to do it, ranging from GridLayouts to RelativeLayouts and then programatic ways to do it.

回答2:

You need the ScrollView to be at same level as ProgressDialog in your Layout.

Here it is in concept:

<RelativeLayout>
    <ProgressDialog>      
    <ScrollView>      
<RelativeLayout>

回答3:

you can insert this into the scrollview tag

android:fillViewport="true"

来源：https://stackoverflow.com/questions/27476534/how-to-make-a-progressbar-stay-in-the-center-of-screen-despite-scrolling

标签

android

vertical-alignment