在android上的listview下方添加一个按钮答案

【问题标题】：Adding a button underneath a listview on android在android上的listview下方添加一个按钮
【发布时间】：2010-02-26 16:07:18
【问题描述】：

所以我一直试图在 android 的列表视图下添加一个按钮，问题是该按钮没有出现。

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
    android:id="@+id/widget0"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <ListView
        android:id="@+id/messagelist"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_x="0px"
        android:layout_y="0px">
    </ListView>
    <Button
        android:id="@+id/addbutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_x="0px"
        android:layout_y="379px">
    </Button>
</AbsoluteLayout>

【问题讨论】：

我们不应该再使用 AbsoluteLayout 了。请改用 LinearLayout 或 RelativeLayout。
我使用 LinearLayout、Listview 和 layout_height="0" 和 weight="1"。

标签： android listview

【解决方案1】：

AbsoluteLayout 已弃用。我建议您改用 LinearLayout：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/widget0"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <ListView
        android:id="@+id/messagelist"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="1">
    </ListView>
    <Button
        android:id="@+id/addbutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button">
    </Button>
</LinearLayout>

我还建议阅读 developer docs on layouts 以获得良好的介绍。

【讨论】：

ListView 高度不要使用 wrap_content，使用 0dip。 Wrap_content 非常昂贵，它不会改变结果。
糟糕，我在示例中颠倒了 layout_width 和 layout_height。修好了。
我尝试了很多方法并找到了您的解决方案。真的很感谢你

【解决方案2】：

“API Demos”示例中有一个这样的布局示例。以下页面链接到示例：

http://developer.android.com/resources/samples/index.html

查找文件LinearLayout9.java，及其对应的布局文件linear_layout9.xml。为方便起见，我将它们粘贴在这里：

LinearLayout9.java：

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.view;

import com.example.android.apis.R;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.ArrayAdapter;

/**
 * Demonstrates how the layout_weight attribute can shrink an element too big
 * to fit on screen.
 */
public class LinearLayout9 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.linear_layout_9);
        ListView list = (ListView) findViewById(R.id.list);
        list.setAdapter(new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, AutoComplete1.COUNTRIES));
    }

}

linear_layout9.xml：

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2007 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<!--
    Demonstrates a simple linear layout. The layout fills the screen, with the
    children stacked from the top.
    -->

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

    <ListView android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1.0" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/linear_layout_9_button" />

</LinearLayout>

【讨论】：