關于Android開發環境的構建方法總結
本方法適用于Android SDK 2.1環境下的程序開發
安裝JDK
• 在java.sun.com下載JDK并安裝。
• 在“系統屬性”的“高級”選項卡中點擊“環境變量”,然后添加如下系統環境變量:
1. 在PATH環境變量后追加 JDK安裝路徑中的bin路徑,本機為:
C:\Program Files\Java\jdk1.6.0_18\bin
2. 新建CLASSPATH環境變量或在CLASSPATH環境變量后追加JDK安裝路徑中的lib路徑和demo路徑,本機為:
C:\Program Files\Java\jdk1.6.0_18\demo;C:\Program Files\Java\jdk1.6.0_18\lib
安裝Eclipse
• 在eclipse.org下載Eclipse IDE for Java Developers的Windows 32bit版本。
• 下載完成后解壓即可使用。
安裝Android SDK OR 離線安裝
• 在Android Developers下載android-sdk_r05-windows.zip,下載完成后解壓到任意路徑。
• 運行SDK Setup.exe,點擊Available Packages,如果沒有出現可安裝的包請點擊Settings,選中Misc中的"Force https://..."這項,再點擊Available Packages 。
• 選擇希望安裝的SDK及其文檔或者其它包,點擊Installation Selected、Accept All、Install Accepted,開始下載安裝所選包
• 添加SDK安裝目錄中的tools文件夾路徑至系統PATH環境變量,本機為:
C:\Android\android-sdk-windows\tools
關于離線安裝
用上面方法更新的時候速度很慢。
更要等很久。所以我們可以直接把那些包下載下來安裝。
地址就是
https://dl-ssl.google.com/androi ... 2.0_r01-windows.zip
https://dl-ssl.google.com/androi ... 2.1_r01-windows.zip
https://dl-ssl.google.com/androi ... -1.1_r1-windows.zip
https://dl-ssl.google.com/androi ... 1.5_r03-windows.zip
https://dl-ssl.google.com/androi ... 1.6_r02-windows.zip
https://dl-ssl.google.com/androi ... ver_r03-windows.zip
https://dl-ssl.google.com/androi ... ogle_apis-6_r01.zip
https://dl-ssl.google.com/androi ... ogle_apis-5_r01.zip
https://dl-ssl.google.com/androi ... ogle_apis-4_r02.zip
https://dl-ssl.google.com/androi ... ogle_apis-7_r01.zip
下完之后,
名字以android的,解壓到platforms里面;
以google_apis開頭的,解壓到addons里面。
usb驅動的,直接解壓到根目錄。
安裝Eclipse插件 ADT
• Start Eclipse, then select Help > Install New Software.
• In the Available Software dialog, click Add...
• In the Add Site dialog that appears, enter a name for the remote site (for example, "Android Plugin") in the "Name" field.
In the "Location" field, enter this URL:
https://dl-ssl.google.com/android/eclipse/
如果無法通過上面的地址獲得插件,可將https替換為http。(https is preferred for security reasons)
• Back in the Available Software view, you should now see "Developer Tools" added to the list.
• Select the checkbox next to Developer Tools, which will automatically select the nested tools Android DDMS and Android Development Tools. Click Next.
• In the resulting Install Details dialog, the Android DDMS and Android Development Tools features are listed.
• Click Next to read and accept the license agreement and install any dependencies, then click Finish.
• Restart Eclipse.
配置ADT
在Eclipse中:
• 選擇Window > Preferences...
• 在左邊的面板選擇Android,然后在右側點擊Browse...并選中SDK路徑,本機為:
C:\Android\android-sdk-windows
• 點擊Apply、OK。配置完成。
創建AVD
為使Android應用程序可以在模擬器上運行,必須創建AVD。
• 在Eclipse中。選擇Windows > Android SDK and AVD Manager
• 點擊左側面板的Virtual Devices,在右側點擊New
• 填入Name,選擇Target的API,SD Card大小任意,Skin隨便選,Hardware目前保持默認值
• 點擊Create AVD即可完成創建AVD
Create a New Android Project
After you've created an AVD, the next step is to start a new Android project in Eclipse.
1. From Eclipse, select File > New > Project.
If the ADT Plugin for Eclipse has been successfully installed, the resulting dialog should have a folder labeled "Android" which should contain "Android Project". (After you create one or more Android projects, an entry for "Android XML File" will also be available.)
2. Select "Android Project" and click Next.
3. Fill in the project details with the following values:
o Project name: HelloAndroid
o Application name: Hello, Android
o Package name: com.example.helloandroid (or your own private namespace)
o Create Activity: HelloAndroid
o Min SDK Version: 7
Click Finish.
Here is a description of each field:
Project Name
This is the Eclipse Project name — the name of the directory that will contain the project files.
Application Name
This is the human-readable title for your application — the name that will appear on the Android device.
Package Name
This is the package namespace (following the same rules as for packages in the Java programming language) that you want all your source code to reside under. This also sets the package name under which the stub Activity will be generated.
Your package name must be unique across all packages installed on the Android system; for this reason, it's very important to use a standard domain-style package for your applications. The example above uses the "com.example" namespace, which is a namespace reserved for example documentation — when you develop your own applications, you should use a namespace that's appropriate to your organization or entity.
Create Activity
This is the name for the class stub that will be generated by the plugin. This will be a subclass of Android's Activity class. An Activity is simply a class that can run and do work. It can create a UI if it chooses, but it doesn't need to. As the checkbox suggests, this is optional, but an Activity is almost always used as the basis for an application.
Min SDK Version(這個是設置程序希望運行在的系統版本)
==================================
Tips: 這里的Min SDK Version會根據我們選擇的Build Target改變,
表示程序將運行在哪個系統版本之上,對應的數值關系如下:
Android 1.5:Level API 3
Android 1.6:Level API 4
Android 2.01:Level API 6
Android 2.1:Level API 7
我們這里選擇Android 2.1,故Min SDK Version為7
==================================
This value specifies the minimum API Level required by your application. If the API Level entered here matches the API Level provided by one of the available targets, then that Build Target will be automatically selected (in this case, entering "2" as the API Level will select the Android 1.1 target). With each new version of the Android system image and Android SDK, there have likely been additions or changes made to the APIs. When this occurs, a new API Level is assigned to the system image to regulate which applications are allowed to be run. If an application requires an API Level that is higher than the level supported by the device, then the application will not be installed.
Other fields: The checkbox for "Use default location" allows you to change the location on disk where the project's files will be generated and stored. "Build Target" is the platform target that your application will be compiled against (this should be selected automatically, based on your Min SDK Version).
Notice that the "Build Target" you've selected uses the Android 1.1 platform. This means that your application will be compiled against the Android 1.1 platform library. If you recall, the AVD created above runs on the Android 1.5 platform. These don't have to match; Android applications are forward-compatible, so an application built against the 1.1 platform library will run normally on the 1.5 platform. The reverse is not true.
Your Android project is now ready. It should be visible in the Package Explorer on the left. Open the HelloAndroid.java file, located inside HelloAndroid > src > com.example.helloandroid).
It should look like this:
下面是點完Finish按鈕之后自動生成的代碼:
import android.app.Activity;
import android.os.Bundle;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
Notice that the class is based on the Activity class. An Activity is a single application entity that is used to perform actions. An application may have many separate activities, but the user interacts with them one at a time. The onCreate() method will be called by the Android system when your Activity starts — it is where you should perform all initialization and UI setup. An activity is not required to have a user interface, but usually will.
Now let's modify some code!
構建 UI
Take a look at the revised code below and then make the same changes to your HelloAndroid class. The bold items are lines that have been added.
下面讓我們修改一下代碼:
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TextView tv = new TextView(this);
tv.setText("Hello, Android");
setContentView(tv);
}
}
Eclipse的插件使得你的程序很容易運行。選擇Run>Open Run Dialog菜單。(Eclipse3.4版本中,菜單為Run->Run Configurations)可以看到這樣的對話框。
下一步,選擇“Android Application”,點擊在左上角(按鈕像一張紙上有個“+”號)或者雙擊“Android Application”。 有個新的選項“New_configuration”。
將名字改得更形象一點,如“Hello,Android”,然后按Browse按鈕選擇你的項目,(如果你Eclipse里有多個Android項 目需要打開,確定要選擇正確)插件會會自動掃描你項目里的活動子類,然后在“活動”的下拉菜單里加載。如果你的“Hello,Android”項目只有一 個,它將被設置為默認項目,然后你可以繼續。
點擊“Apply”按鈕,這里有個例子:
這樣就可以了,點擊“Run”按鈕,Android的模擬器啟動。一啟動你的程序就會出現,當一切OK,你可以看到:
這樣就可以了,點擊“Run”按鈕,Android的模擬器啟動。
啟動完畢后你的程序就會出現,
如果不出現,有時候是因為有鍵盤鎖的原因,
用鼠標將鍵盤鎖解開就一切OK,你可以看到:Hello Android.
使用XML構建UI
你剛剛完成的“Hello, World”的例子使用的是我們稱為“可編程”的UI層,意思是你通過編寫代碼來組建UI層。當你開發了足夠多的UI程序,你會發現一些很糟糕的現象: 一些小的變化需要你做大量的代碼改動。你常常會忘記將View連接起來,這樣會導致一些錯誤,浪費你很多時間去調試代碼。
這就是Android為什么提供一個可變化的UI開發模塊:基于XML的文件。最簡單解釋這個概念就是演示個例子。這里有個XML的文件,它能達到和你剛才完成代碼同樣的效果:
通常Android里XML文件結構是很簡單的。只是一些標記的樹形集合,每個標記就是一個視圖類。在這個例子中,它就是一個簡單的 TextView元素的樹,你可以在XML文件里使用任何擴展類的名字作為你的標記,這也包括你在你的自己的代碼里定義的名字。這個結構使得你能使用簡單 結構和語法快速的組建UI,這種模型就像網站的開發模型,你能夠將UI和程序邏輯分開,單獨獲取或者填充數據。
在這個例子里,有4個XML屬性,下面是屬性的大概意思:
xmlns:android 這是一個XML命名空間,告訴Android開發工具你準備使用Android命名空間里的一些通用屬性。在所有Android XML設計文件中最外層的標記必須使用這個屬性。
android:layout_width 這個屬性定義了這個視圖需要占用的屏幕寬度。在這個例子中,我們僅有的一個視圖可以占用整個屏幕,那就是“fill_parent”的意思。
android:layout_height 這個和“layout_width”差不多,表示占用屏幕的高度。
android:text 這個設置文本顯示內容,在這個例子里,我們使用“Hello,Android”。
這就是XML的布局,你需要把這個文件放在什么位置? 放在你的工程/res/layout下就可以。“res”是“resource”的簡稱,這個目錄包含了所有應用程序需要的非代碼部分。比如圖片、字符串、XML文件。
Eclipse插件為你創建了這些XML文件中的一個。在我們上面的范例,我們根本沒有使用過它。在包的管理器里,展開目錄/res/layout,編輯main.xml文件,替換上面的文本然后保存修改。
在從代碼目錄里打開 HelloAndroid/gen/com.example.helloandroid/R.java文件,你可以看到他們像這樣:
R.java是文件中所有資源的索引界定值定義。你在代碼中使用這個類,就像在你的項目里使用一個簡潔的方法表示你的資源。在Eclipse這樣的IDE工具里,這個方式對于代碼自動完成功能還是非常有效的,因為這能讓你快速得定位你要尋找的東西。
有個重要點需要注意的是有個內部類“main”,是“layout”的成員類。Eclipse插件提醒你加了一個新的XML文件,然后生成R.java文件,當你加入其他資源到你的工程里,你可以看到R.java在同步更改。