加入权限是不可少的

<uses-permission android:name="android.permission.GET_ACCOUNTS" /> 
import android.accounts.Account; 
import android.accounts.AccountManager; 
import android.content.Context; 
 
/** 
 *  
 * 这个呢就是只得到主email也就是google
 */ 
public class UserEmailFetcher { 
 
  static String getEmail(Context context) { 
    AccountManager accountManager = AccountManager.get(context);  
    Account account = getAccount(accountManager); 
 
    if (account == null) { 
      return null; 
    } else { 
      return account.name; 
    } 
  } 
 
  private static Account getAccount(AccountManager accountManager) { 
    Account[] accounts = accountManager.getAccountsByType("com.google"); 
    Account account; 
    if (accounts.length > 0) { 
      account = accounts[0];       
    } else { 
      account = null; 
    } 
    return account; 
  } 
}


2.


Account[] accounts = AccountManager.get(this).getAccounts(); 
for (Account account : accounts) { 
  // TODO: Check possibleEmail against an email regex or treat 
  // account.name as an email address only for certain account.type values. 
  String possibleEmail = account.name; 
  ... 
}

3.第三方

http://donpark.org/blog/2009/01/24/android-client-side-oauth

 in case anyone is interested: I have written an OAuth library for Java that works pretty well with Android. Check it out at http://code.google.com/p/oauth-signpost