android absolutelayout对齐中心

Question

I have a simple android app that contain scrollview and inside it there is absolutelayout and I want them to be in the center. when I see the graphical layout in eclipse the absolutelayout is in the center of the screen like this:

here is my code:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="400dp"
android:layout_height="fill_parent"
android:background="@drawable/bg"
android:gravity="center_vertical" >

<AbsoluteLayout
    android:id="@+id/AbsoluteLayout1"
    android:layout_width="284dp"
    android:layout_height="562dp"
    android:layout_marginBottom="40dp"
    android:layout_marginLeft="18dp"
    android:layout_marginRight="18dp"
    android:layout_marginTop="26dp"
    android:background="@drawable/bg4"
     >

    <TextView
        android:id="@+id/textView2"
        android:layout_width="244dp"
        android:layout_height="500dp"
        android:layout_x="20dp"
        android:layout_y="81dp"
        android:text="Info here"
        android:textColor="#ffffff" />

  </AbsoluteLayout>

</ScrollView>

Answer 1

Firstly, AbsoluteLayout is deprecated so you probably shouldn't use it. I'd suggest RelativeLayout instead.

As for the ScrollView, make sure to supply the android:fillViewport="true" and then set the child layout's layout_width="match_parent" like so:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView  xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true"
    android:background="#444444">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical" >

        <Button android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:text="Button"/>

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_below="@id/button"
            android:text="Info here"
            android:textColor="#ffffff" />

    </RelativeLayout>

</ScrollView>

This will handle the case where the ScrollView's child width is less than the width of the ScrollView itself.

Answer 2

You don't have to use Scroll View for this. There are a couple of XML properties you can add to your TextView in order to make it scrollable.

Use this:

android:maxLines = "AN_INTEGER"

android:scrollbars = "vertical"

Then in your Java class:

yourTextView.setMovementMethod(new ScrollingMovementMethod())