在Android上的列表視圖下添加一個按鈕

Question

所以我一直試圖在Android下的ListView下添加一個按鈕，問題是這個按鈕沒有出現。

<?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> 

Answer 1

AbsoluteLayout已棄用。我建議，而不是您使用的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> 

我也建議通過developer docs佈局上閱讀一個很好的介紹。

Answer 2

在「API演示」示例中有一個這樣的佈局的示例。以下頁面鏈接到樣本：

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

查找文件LinearLayout9.java，及其相應的佈局文件linear_layout9.xml。爲方便起見，我在這裏貼上他們：

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>