LinearLayout在ScrollView Android中被切断了

Question

I have an activity in my app where I would like the user to be able to vertically scroll the content contained inside a LinearLayout which in turn is inside a ScrollView . Here is a summary of what the layout XML for this activity looks like:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ScrollView
        android:layout_width="fill_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_margin="20dip"
            android:orientation="vertical">

            <!-- a bunch of standard widgets, omitted for brevity -->

            <!-- everything renders but starting in this TextView -->
            <!-- content begins to get truncated -->
            <TextView
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:paddingLeft="20dp"
                android:gravity="left"
                android:textSize="20dip"/>

            <!-- this View, really just a trick for a horizontal row, is -->
            <!-- completely cutoff -->
            <View
                android:layout_width="fill_parent"
                android:layout_height="2dip"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="10dp"
                android:background="@color/green" />
        </LinearLayout>
    </ScrollView>
</LinearLayout>

What I am observing is that content in the inner LinearLayout is being cutoff inside the ScrollView . In the final TextView above, when it contains little text, then the View below it does render in portrait, but does not in landscape. When this TextView contains a lot of text, then it gets cutoff in portrait mode.

I tried the recommendations I found on Stack Overflow. Adding bottom padding to the ScrollView did not resolve the problem, nor did swapping the ScrollView for a NestedScrollView .

Any helpful suggestions would be welcome. This is actually turning out to be a blocker.

Answer 1

Change your inner LinearLayout 's margin to padding. Or, if you really need it to be margin (maybe you're using a custom background), wrap your LinearLayout in a FrameLayout .

The ScrollView is taking its height (or, more accurately, it is computing its scrollable range) from the LinearLayout . This value doesn't include margins, so your ScrollView is going to be "too short" by the sum of the LinearLayout 's top and bottom margins.

Answer 2

The margins are ignored while measuring, See this

So you can provide padding to your ScrollView and remove margins from your LinearLayout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <!-- a bunch of standard widgets, omitted for brevity -->

        <!-- everything renders but starting in this TextView -->
        <!-- content begins to get truncated -->
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingLeft="20dp"
            android:gravity="left"
            android:textSize="20dip"/>

        <!-- this View, really just a trick for a horizontal row, is -->
        <!-- completely cutoff -->
        <View
            android:layout_width="match_parent"
            android:layout_height="2dip"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp"
            android:background="@color/green" />
    </LinearLayout>
</ScrollView>

Also fill_parent is deprecated and renamed match_parent in API Level 8 and higher