在第一个应用程序中，添加一个intent-filter 以从第二个应用程序（即您的Register 应用程序）接收数据。
现在，对您的 Register 应用程序执行相同操作，我们需要这样做，以便我们可以从我们的第一个应用程序调用它。
intent-filter 用于确保我们可以发回数据。根据https://developer.android.com/guide/components/intents-filters：
要宣传您的应用可以接收哪些隐式 Intent，请使用清单文件中的一个元素为您的每个应用组件声明一个或多个 Intent 过滤器。
从第一个应用程序创建一个Intent，它将带您进入第二个应用程序。如果您不想打开Android share sheet，那么我建议您使用PackageManager 来获取所有可以接收您的数据的活动，然后在列表中找到您的第二个应用程序并使用setComponent() 打开它intent。 （检查我下面的代码）
在我们的第二个应用程序中，执行与第一个应用程序相同的操作，但现在您可以添加您的 extras 或名字和名字等数据。
回到我们的第一个应用程序，编写将从我们的第二个应用程序接收传入的intent 的代码，然后就完成了！
参考：
https://developer.android.com/training/sharing
有关使用意图发送/接收数据的更多信息。
这是一个示例代码：
第一个应用程序的主要活动
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Receive your data here from your Register app
Intent receivedIntent = getIntent();
String action = receivedIntent.getAction();
String type = receivedIntent.getType();
if (Intent.ACTION_SEND.equals(action) && type != null) {
if ("text/plain".equals(type)) {
handleReceivedData(receivedIntent);
}
}
}
private void handleReceivedData(Intent intent) {
String firstName = intent.getStringExtra("first_name");
String secondName = intent.getStringExtra("second_name");
if (firstName == null || secondName == null) {
Toast.makeText(this, "Cannot received data!", Toast.LENGTH_SHORT).show();
return;
}
// Do here what you want with firstName and secondName
// ...
Toast.makeText(this, "First name: " + firstName +
" Second name: " + secondName, Toast.LENGTH_SHORT).show();
}
public void open(View view) {
Intent sendIntent = new Intent();
sendIntent.setAction(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT,
"Here you can put a message for your 'register' application");
sendIntent.setType("text/plain");
PackageManager packageManager = getPackageManager();
List<ResolveInfo> activities = packageManager.queryIntentActivities(sendIntent,
PackageManager.MATCH_DEFAULT_ONLY);
////////////////// Get the other application package name //////////////////
// This is so the user cannot choose other apps to send your data
// In order words, this will send the data back to the other
// application without opening the Android Share sheet
ActivityInfo activityInfo = null;
for (ResolveInfo activity: activities) {
// Specify here the package name of your register application
if (activity.activityInfo.packageName.equals("com.example.registerapp")) {
activityInfo = activity.activityInfo;
break;
}
}
// If the other application is not found then activityInfo will be null
// So make sure you add the correct intent-filter there!
if (activityInfo != null) {
// This will open up your register application
ComponentName name = new ComponentName(activityInfo.applicationInfo.packageName,
activityInfo.name);
sendIntent.setComponent(name);
startActivity(sendIntent);
}
else {
Toast.makeText(this,
"Receiver app doesn't exist or not installed on this device!",
Toast.LENGTH_SHORT).show();
}
}
第一个应用程序的清单
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.SEND" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" />
</intent-filter>
</activity>
第二个应用程序的接收器活动（在这种情况下，您的注册应用程序）
注意：如您所愿，这不是主要活动
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receiver);
// This is NOT the main activity!
}
public void send(View view) {
// I just want to note that I am calling the receiving application: "other application"
EditText firstNameEditText = findViewById(R.id.firstNameEditText);
EditText secondNameEditText = findViewById(R.id.secondNameEditText);
String firstName = firstNameEditText.getText().toString().trim();
String secondName = secondNameEditText.getText().toString().trim();
// Check if any of the inputs are empty
if (firstName.isEmpty() || secondName.isEmpty()) {
Toast.makeText(this, "Text boxes cannot be empty!", Toast.LENGTH_SHORT).show();
return;
}
// Send data back to the other application
Intent sendBackIntent = new Intent();
sendBackIntent.setAction(Intent.ACTION_SEND);
sendBackIntent.putExtra("first_name", firstName);
sendBackIntent.putExtra("second_name", secondName);
sendBackIntent.setType("text/plain");
// Get all the available applications that can receive your data
// (in this case, first name and second name)
PackageManager packageManager = getPackageManager();
List<ResolveInfo> activities = packageManager.queryIntentActivities(sendBackIntent,
PackageManager.MATCH_DEFAULT_ONLY);
////////////////// Get the other application package name //////////////////
ActivityInfo activityInfo = null;
for (ResolveInfo activity: activities) {
// Specify here the package name of the other application
if (activity.activityInfo.packageName.equals("com.example.mainapp")) {
activityInfo = activity.activityInfo;
break;
}
}
if (activityInfo != null) {
// Same as before, this will open up the other application
ComponentName name = new ComponentName(activityInfo.applicationInfo.packageName,
activityInfo.name);
sendBackIntent.setComponent(name);
startActivity(sendBackIntent);
}
else {
Toast.makeText(this,
"Receiver app doesn't exist or not installed on this device!",
Toast.LENGTH_SHORT).show();
}
}
第二个应用程序的清单
<activity android:name=".ReceiverActivity">
<intent-filter>
<action android:name="android.intent.action.SEND" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" />
</intent-filter>
</activity>
编码愉快！
编辑：我在答案中添加了解释。