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Android - RelativeLayout布局

RelativeLayout布局


本文地址:http://blog.csdn.net/caroline_wendy


RelativeLayout是一种相对布局方式,是根据属性进行对齐;
A Layout where the positions of the children can be described in relation to each other or to the parent.
在布局中,子控件的位置根据相互之间的关系进行描述。
Note that you cannot have a circular dependency between the size of the RelativeLayout and the position of its children. 
子控件之间不能存在循环依赖。

Note: In platform version 17 and lower, RelativeLayout was affected by a measurement bug that could cause child views to be measured with incorrect MeasureSpec values. This was triggered when a RelativeLayout container was placed in a scrolling container, such as a ScrollView or HorizontalScrollView. If a custom view not equipped to properly measure with the MeasureSpec mode UNSPECIFIED was placed in a RelativeLayout, this would silently work anyway as RelativeLayout would pass a very large AT_MOST MeasureSpec instead.
This behavior has been preserved for apps that set android:targetSdkVersion="17" or older in their manifest‘s uses-sdk tag for compatibility. Apps targeting SDK version 18 or newer will receive the correct behavior

属性名称

描述

android:layout_below

摆放在指定组件的下边

android:layout_toLeftOf

摆放在指定组件的左边

android:layout_toRightOf

摆放在指定组件的右边

android:layout_alignTop

以指定组件作为参考进行上对齐

android:layout_algnBottom

以指定组件作为参照进行下对齐

android:layout_alignLeft

以指定组件作为参考进行左对齐

android:layout_alignRight

以指定组件

 

android:layout_toStartOf="@+id/buttonTweet” //表是在某个控件的前对齐,如果不知道,就图形界面拖动
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".StatusActivity">


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_tweet"
        android:id="@+id/buttonTweet"
        android:layout_alignParentEnd="true"/>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="textMultiLine"
        android:ems="10"
        android:id="@+id/editText"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:hint="@string/hint_status"
        android:layout_toStartOf="@+id/buttonTweet"/>


    <TextView
        android:id="@+id/textCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignEnd="@id/buttonTweet"
        android:layout_below="@id/buttonTweet"
        android:text="140"
        android:textAppearance="?android:textAppearanceSmall"/>

</RelativeLayout>



Android - RelativeLayout布局