[Android] Facebook API for Android

內文舊了，請先直接到官方文件看
https://developers.facebook.com/docs/ 



結合Facebook到Android程式中的JAVA函式庫
https://github.com/facebook/facebook-android-sdk

安裝環境

1. 從GitHub取得函式庫:

git clone git://github.com/facebook/facebook-android-sdk.git

1. 照 Android SDK Getting Started Guide 設定模擬器和編輯器
2. Facebook Android SDK 運作在任何 Android 開發環境，如Eclipse:
3. 建立new project 以 Facebook SDK 在 Eclipse workspace.
4. File -> New -> Project -> Android Project -> Next.
5. 選 "Create project from existing source".
6. 選 facebook 目錄. You should see the project properties populated (你可以把Project名稱設成 "FacebookSDK").
7. 按 Finish 繼續

這時API就設定好準備讓其它程式去引用他

範例程式

這個函式庫內含兩個範例程式指導你開發

• simple: 簡單的範例來展示授權、使用API、取得對話框

• stream: 可以看見你在Facebook上的消息的範例

安裝範例程式到Eclipse (3.5):

• Select File -> New -> Project, choose Android Project, and then click Next.


• Select "Create project from existing source".


• Choose either examples/simple or examples/stream. You should see the project properties populated.


• Click Finish to continue.


• "Build Project".


• "Run Configurations..."

整合到現有程式

最簡單的方式是修改範例程式來結合facebook，但如果你需要整合到已有或想建立一個乾淨的專案的話：

• Add a dependency on the Facebook Android SDK library on your application:
  
  
  
  1. Select File -> Properties. Open the Android section within the Properties dialog.
  
  
  2. In the bottom Library section, click Add... and select the Facebook SDK project.
  
  
  3. 有問題? 查手冊吧 Android documentation

• 允許你的程式使用網路 (android.permission.INTERNET) 在 Android manifest 加上:

• 註冊你的程式在 Facebook:
  
  
  
  1. 建立一個新的 Facebook 應用程式: http://www.facebook.com/developers/createapp.php . 如果你建立過同應用於PHP之類的
     ，你可以用同一組 application ID.
  
  
  2. 設定facebook上的應用程式資訊.

設定登入

選用，你可以讓你的登入系統結合Facebook做單一登入用

• 註冊你的Android facebook Key Hash

1. 產生 key hash:[code]keytool -exportcert -alias [alias] -keystore [keystore]
   | openssl sha1 -binary
   | openssl base64[/code]


2. 到 Facebook developer settings  Mobile and Devices


3. 在 Android 部份輸入 Key Hash

• 插入並呼叫 authorizeCallback() 方法在Activity的 onActivityResult() 函式. (如果沒有 onActivityResult 就建立它)

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
facebook.authorizeCallback(requestCode, resultCode, data);
// ... anything else your app does onActivityResult ...
}

用法

建立一個 Facebook 物件:

facebook = new Facebook(applicationId);

 此 Facebook 物件主要能做三件事：

• 認證 and 授權: prompt users to log in to facebook and grant permissions to your application.


• 建立 API 呼叫: fetch user profile data (such as name and profile pic), as well as info about a user's friends.


• 顯示對話框: interact with user via a WebView. You primarily use this to publish to a user's feed without requiring upfront permissions.

認證 and 授權

Making the authorize request

To login the current user, call the authorize() method. By default, your application can read the user's basic information, which includes their name, profile picture, list of friends, and other information that they have made public.

[java]facebook.authorize(context, new AuthorizeListener());[/java]

Private user information is protected by a set of granular permissions. If you want to access private information, use the authorize() method to request permission:

[java]facebook.authorize(context,
String[] {"offline_access","user_photos"},
new AuthorizeListener())[/java]

You should use one of the buttons provided in the images/buttons/ directory to direct the user to login.

Login process

If the user has installed and is logged into the latest Facebook application on their device, then they will be directed to the Facebook app to grant permissions. If the user is not logged in, then they will need to do that first. If the Facebook application is not installed at all, then the Facebook Android SDK will gracefully fall back to a WebView-based flow that requires username/password.

Handle the authorize response

Your application handles the response with the onComplete method of a DialogListener object.

[java]class AuthorizeListener implements DialogListener {
public void onComplete(Bundle values) {
//  Handle a successful login
}
}[/java]

Check out the sample listeners for more details on the DialogListener interface.

Logging out

如果使用者想停止 Facebook 整合到你的 application ，你可以呼叫 logout method 清除程式狀態。

[java] facebook.logout(context);[/java]

建立 API 呼叫

通用API?

Facebook Graph API 目前很單純，取得使用者資訊、留言和朋友們

你可以連結 Graph API 呼叫"request" method。 例如:

[java]facebook.request("me");               // 取得登入者資訊
facebook.request("platform/posts");   // get the posts made by the "platform" page
facebook.request("me/friends");       // 取得登入者的朋友們
[/java]

因為要求是同步的，不會馬上呈現出來，所以不要呼叫在你的主程式內(如C的main)

請用一個執行緒(thread)去呼叫API，例如:

[java]
new Thread() {
@Override public void run() {
String resp = request("me");
handleResponse(resp);
}
}.start();
[/java]

查看 AsyncFacebookRunner class 和範例去實行異步查詢(asynchronous requests)



Response format

此服務的 response 是 JSON string. SDK 提供了 Util.parseJson() method 轉換 JSONObject,

whose fields and values can be inspected and accessed.

The sample implementation checks for a variety of error conditions and raises JSON or Facebook exceptions

if the content is invalid or includes an error generated by the server.

Advanced applications may wish to provide their own parsing and error handling.

Old REST API

The Old REST API is also supported. To access the older methods, pass in the named parameters and method name as a dictionary Bundle.

[java]
Bundle parameters = new Bundle();
parameters.putString("method", "auth.expireSession");
String response = request(parameters);
[/java]

See the comments on the request method for more details.

顯示對話框

SDK 提供一個 method 彈出 Facebook dialog 與使用者互動。 他可以輕易讓你的使用者發送意見，第一次使用時需要授權。

使用對話框:

[java]
facebook.dialog(context,
"feed",
new SampleDialogListener());
[/java]

錯誤資訊

Here's a few common errors and their solutions.

• Build error: "missing gen files".
  重構你的project 試試 Project 的  Clean...
• Error: "invalid_key"
  This error means that the Facebook server doesn't recognize your Android key hash. Make sure that you correctly generated and copy/pasted your key hash into the Facebook developer settings console (http://www.facebook.com/developers/apps.php), and make sure that your application has been signed with the same key you registered with Facebook.
• Dialog won't load or shows a blank screen.
• I can't upload photos with photos.upload.
  請確定Bundle value 於 photo 參數是 byte array.