如何獲取Android裝置的主郵箱地址？

此示例演示如何獲取Android裝置的主郵箱地址。

步驟1 - 在Android Studio中建立一個新專案，轉到檔案 ⇒ 新建專案，並填寫所有必需的詳細資訊以建立新專案。

步驟2 - 將以下程式碼新增到res/layout/activity_main.xml。

<?xml version="1.0" encoding="utf-8"?>
<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:padding="8dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_centerInParent="true"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textSize="24sp"
      android:textStyle="bold"
      android:textAlignment="center"
      android:text="Primary email Address: testemail@gmail.com" />
</RelativeLayout>

步驟3 - 將以下程式碼新增到src/MainActivity.java

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.util.Patterns;
import android.widget.TextView;
import android.widget.Toast;
import java.util.regex.Pattern;
public class MainActivity extends AppCompatActivity {
   private Activity activity = MainActivity.this;
   private static final int PERMISSION_REQUEST_CODE = 1;
   TextView textView;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      textView = findViewById(R.id.textView);
      String wantPermission = Manifest.permission.GET_ACCOUNTS;
      if (!checkPermission(wantPermission)) {
         requestPermission(wantPermission);
      } else {
         getEmails();
      }
   }
   private void getEmails() {
      Pattern emailPattern = Patterns.EMAIL_ADDRESS;
      Account[] accounts = AccountManager.get(this).getAccounts();
      for (Account account : accounts) {
         if (emailPattern.matcher(account.name).matches()) {
            String TAG = "MainActivity";
            Log.d(TAG, String.format("%s - %s", account.name, account.type));
            textView.setText("Primary email Address: " + accounts.toString());
         }
      }
   }
   private boolean checkPermission(String permission) {
      if (Build.VERSION.SDK_INT >= 23) {
         int result = ContextCompat.checkSelfPermission(activity, permission);
         return result == PackageManager.PERMISSION_GRANTED;
      } else {
         return true;
      }
   }
   private void requestPermission(String permission) {
      if (ActivityCompat.shouldShowRequestPermissionRationale(activity, permission)) {
         Toast.makeText(activity, "Get account permission allows us to get your email", Toast.LENGTH_LONG).show();
      }
      ActivityCompat.requestPermissions(activity, new String[]{permission}, PERMISSION_REQUEST_CODE);
   }
   @Override
   public void onRequestPermissionsResult(int requestCode, @NonNull String[]
   permissions, @NonNull int[] grantResults) {
      if (requestCode == PERMISSION_REQUEST_CODE) {
         if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            getEmails();
         } else {
            Toast.makeText(activity, "Permission Denied.", Toast.LENGTH_LONG).show();
         }
      }
   }
}

步驟4 - 將以下程式碼新增到androidManifest.xml

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

讓我們嘗試執行您的應用程式。我假設您已將您的實際Android移動裝置連線到您的計算機。要從Android Studio執行應用程式，請開啟專案的其中一個活動檔案，然後單擊執行工具欄中的圖示。選擇您的移動裝置作為選項，然後檢查您的移動裝置，它將顯示您的預設螢幕 -