onActivityResult得到null意图

Question

在这种情况下，两个活动A和B应该以A方式调用B来获得结果。

，但一个永远不会从B.

任何数据传回此代码看起来像任何教程或SO的问题，我都看到了。

调试会话确认调用了setResult。

这个问题是抢劫我的动机，如果有人能指出我失踪的事情会很好。

编辑：代码在我的物理目标设备上执行时不起作用，但在nexus 5设备上运行查找。我可以尝试找出原因？

MainActivity.java

package iifym.apps.rnoennig.de.myapplication; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Toast; 

public class MainActivity extends Activity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.main); 
    } 

    public void onClick(View view) { 
     Intent in = new Intent(this, SecondActivity.class); 
     in.putExtra("mau", "bar"); 
     startActivityForResult(in, 1); 
    } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     // data is null ;(
     Toast.makeText(this, String.valueOf(data), Toast.LENGTH_SHORT).show(); 
    } 
} 

SecondActivity.java

package iifym.apps.rnoennig.de.myapplication; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Toast; 

public class SecondActivity extends Activity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.second); 

     Toast.makeText(this, String.valueOf(getIntent()), Toast.LENGTH_SHORT).show(); 
    } 

    public void onClick(View view) { 
     setResult(RESULT_OK, new Intent().putExtra("foo", "bar")); 
     finish(); 
    } 
} 

布局/ main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="New Button" 
     android:id="@+id/button" 
     android:layout_gravity="center_horizontal" 
     android:onClick="onClick" 
     /> 
</LinearLayout> 

布局/ second.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="New Button" 
     android:id="@+id/button2" 
     android:layout_gravity="center_horizontal" 
     android:onClick="onClick" 
     /> 
</LinearLayout> 

AndroidManifest.xml中

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="iifym.apps.rnoennig.de.myapplication"> 

    <application 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:label="@string/app_name" 
     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> 
     <activity android:name=".SecondActivity"></activity> 

    </application> 

</manifest> 

Answer 1

为我工作。 （相同的布局和清单）。

主要

public class MainActivity extends AppCompatActivity { 

    public static final int MAIN_REQUEST = 1; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
    } 

    public void onClick(View v) { 
     Intent in = new Intent(MainActivity.this, SecondActivity.class); 
     in.putExtra("mau", "start 2nd"); 
     startActivityForResult(in, MAIN_REQUEST); 
    } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     if (requestCode == MAIN_REQUEST) { 
      if (resultCode == RESULT_OK) { 
       Toast.makeText(MainActivity.this, data.getStringExtra("foo"), Toast.LENGTH_SHORT).show(); 
      } 
     } 
    } 
} 

二

public class SecondActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_second); 

     Intent sent = getIntent(); 
     if (sent != null) { 
      Toast.makeText(SecondActivity.this, sent.getStringExtra("mau"), Toast.LENGTH_SHORT).show(); 
     } 
    } 

    public void onClick(View v) { 
     setResult(RESULT_OK, new Intent().putExtra("foo", "finish 2nd")); 
     finish(); 
    } 
}