Android中的Download(下載) 項目 詳解

環境: Android 0.5.2 + gradle 1.11 + kindle fire

Download, 下載項目, 從Internet上下載資源, 並存入本地SD卡.

點擊Download按鈕, 下載圖片, 然後顯示下載內容, 可以點擊查看.

Download的具體設計:

1. 修改activity_main.xml

位置: res->layout->activity_main.xml

<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="mzx.spike.download.app.MainActivity">  
      
    <Button
        android:id="@+id/download_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Download" />  
      
    <TextView
        android:text="@string/hello_world"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/download_button"  />  
      
</RelativeLayout>

添加一個按鈕(Button), 使"hello_world"在其下方, 使用layout_below屬性;

2. 修改AndroidManifest.xml

位置: main->AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>  
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="mzx.spike.download.app" >  
      
    <uses-permission android:name="android.permission.INTERNET" />  
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />  
          
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >  
        <activity
            android:name="mzx.spike.download.app.MainActivity"
            android:label="@string/app_name" >  
            <intent-filter>  
                <action android:name="android.intent.action.MAIN"  />  
      
                <category android:name="android.intent.category.LAUNCHER"  />  
            </intent-filter>  
        </activity>  
    </application>  
      
</manifest>

需要INTERNET, 連接互聯網的權限; WRITE_EXTERNAL_STORAGE, 寫入存儲器的權限;