Android中的layout

最新推荐文章于 2022-09-07 19:58:36 发布

转载最新推荐文章于 2022-09-07 19:58:36 发布 · 1k 阅读

Android 专栏收录该内容

28 篇文章

订阅专栏

本文深入解析了Android中LinearLayout布局中weight和gravity的概念及其计算方法，同时详细介绍了Relativelayout参数的使用，帮助开发者更好地掌握Android布局管理。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1. Linear Layout中的weight和gravity的作用。

先看看下面的例子：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:orientation="vertical" >
    <EditText
        android:layout_width="100dp"
        android:gravity="right"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:hint="@string/to" />
    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:hint="@string/subject" />
    <EditText
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="10"
        android:gravity="bottom"
        android:hint="@string/message" />
    <Button
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:text="@string/send" />
</LinearLayout>

效果是：

从上图可以知道，weight的计算方法是：

1+1+2=4,所有第一个EditText会占总空间（除过最后一个EditText）的25%，第二个也是25%，第三个是50%。

gravity的作用是View的内容的显示方式是从哪里开始。

（Specifies how an object should position its content, on both the X and Y axes, within its own bounds. ）

http://developer.android.com/reference/android/widget/LinearLayout.html

2. Relative layout中的参数

XML Attributes
Attribute Name	Related Method	Description
android:layout_above		Positions the bottom edge of this view above the given anchor view ID.
android:layout_alignBaseline		Positions the baseline of this view on the baseline of the given anchor view ID.
android:layout_alignBottom		Makes the bottom edge of this view match the bottom edge of the given anchor view ID.
android:layout_alignEnd		Makes the end edge of this view match the end edge of the given anchor view ID.
android:layout_alignLeft		Makes the left edge of this view match the left edge of the given anchor view ID.
android:layout_alignParentBottom		If true, makes the bottom edge of this view match the bottom edge of the parent.
android:layout_alignParentEnd		If true, makes the end edge of this view match the end edge of the parent.
android:layout_alignParentLeft		If true, makes the left edge of this view match the left edge of the parent.
android:layout_alignParentRight		If true, makes the right edge of this view match the right edge of the parent.
android:layout_alignParentStart		If true, makes the start edge of this view match the start edge of the parent.
android:layout_alignParentTop		If true, makes the top edge of this view match the top edge of the parent.
android:layout_alignRight		Makes the right edge of this view match the right edge of the given anchor view ID.
android:layout_alignStart		Makes the start edge of this view match the start edge of the given anchor view ID.
android:layout_alignTop		Makes the top edge of this view match the top edge of the given anchor view ID.
android:layout_alignWithParentIfMissing		If set to true, the parent will be used as the anchor when the anchor cannot be be found for layout_toLeftOf, layout_toRightOf, etc.
android:layout_below		Positions the top edge of this view below the given anchor view ID.
android:layout_centerHorizontal		If true, centers this child horizontally within its parent.
android:layout_centerInParent		If true, centers this child horizontally and vertically within its parent.
android:layout_centerVertical		If true, centers this child vertically within its parent.
android:layout_toEndOf		Positions the start edge of this view to the end of the given anchor view ID.
android:layout_toLeftOf		Positions the right edge of this view to the left of the given anchor view ID.
android:layout_toRightOf		Positions the left edge of this view to the right of the given anchor view ID.
android:layout_toStartOf		Positions the end edge of this view to the start of the given anchor view ID.