This HorizontalScrollView layout or its LinearLayout parent is useless

问题

I am new in android programming I have problem with horizontalscrollview. I have error "This HorizontalScrollView layout or its LinearLayout parent is useless" on

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="lv.myproject.formula.MainFormula"
    tools:ignore="MergeRootFrame"
    android:orientation="vertical">


    <HorizontalScrollView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp" 
        >

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal" 
            android:background="@drawable/bgtest">

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Button1" />

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Button2" />

        </LinearLayout>
    </HorizontalScrollView>

</LinearLayout>

回答1:

First of all, this is not an error but a warning - the code will still work correctly.

Now, as you can see, you have:

<LinearLayout ...>
    <HorizontalScrollView ...>

    </HorizontalScrollView ...>
</LinearLayout>

There is only one child in the LinearLayout - and it's another ViewGroup - therefore you can get rid of the outer LinearLayout and simply keep the HorizontalScrollView:

<?xml version="1.0" encoding="utf-8"?>
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="lv.myproject.formula.MainFormula"
    tools:ignore="MergeRootFrame"
    android:layout_marginTop="50dp" >

    ...
</HorizontalScrollView>

However if you are adding any Views to the LinearLayout in your code (i.e. as siblings to your HorizontalScrollView) then the correct thing is to ignore this warning.

来源：https://stackoverflow.com/questions/22938250/this-horizontalscrollview-layout-or-its-linearlayout-parent-is-useless

标签

android

android-layout

horizontalscrollview