不幸myapp已經停止

Question

我正在獲取應用程序已停止。該項目將MainAplication更改爲JobList，但將Job List更改爲ExerciseList，我正在開始這些「不幸的應用程序已停止」。在模擬器上。這是我的課程。我也在logcat上開始致命EXCEPTİN。

ApplicationMain.java

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

    public class ApplicationMain extends Activity { 
/** Called when the activity is first created. */ 
EditText nameEditCtrl; 
Button btnCtlr; 
String name; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    nameEditCtrl = (EditText) findViewById(R.id.editText1); 
    btnCtlr = (Button) findViewById(R.id.button1); 
    btnCtlr.setOnClickListener(new ButtonClickHandler()); 
} 

public class ButtonClickHandler implements View.OnClickListener { 
    public void onClick(View view) { 
     if (nameEditCtrl != null && nameEditCtrl.getText().length() != 0) { 
      name = nameEditCtrl.getText().toString(); 
     } else { 
      name = "Guest"; 
     } 
     Intent intObj = new Intent(ApplicationMain.this, 
       JobList.class); 
     intObj.putExtra("USERNAME", name); 
     startActivity(intObj); 
    } 
} 
} 

JobList.Java

import android.app.Activity; 
    import android.content.Intent; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.widget.Button; 
    import android.widget.EditText; 
    import android.widget.ImageButton; 
    import android.widget.TextView; 

    public class JobList extends Activity { 
TextView greetMsg; 
ImageButton ib; 

/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.joblist); 
    greetMsg = (TextView) findViewById(R.id.textView1); 
    Intent intename = getIntent(); 
    String uname = (String) intename.getSerializableExtra("USERNAME"); 
    greetMsg.setText("Welcome " + uname); 



    ib = (ImageButton) findViewById(R.id.imageButton1); 
    ib.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      Intent intObj = new Intent(JobList.this,ExerciseList.class); 
      startActivity(intObj); 
     } 
    }); 





    } 

} 

ExerciseList.Java

 import android.app.Activity; 
     import android.content.Intent; 
     import android.os.Bundle; 
     import android.view.View; 
     import android.widget.Button; 
     import android.widget.EditText; 
     import android.widget.ImageButton; 
     import android.widget.TextView; 


    public class ExerciseList extends Activity { 

ImageButton iz; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.exerciselist); 

    iz = (ImageButton) findViewById(R.id.imageButton2); 
     iz.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 

      Intent intObj = new Intent(ExerciseList.this, 
        ApplicationMain.class); 
      //intObj.putExtra("USERNAME", name); 
      startActivity(intObj); 
     } 
    }); 


} 
} 

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.prgguru.android" 
android:versionCode="1" 
android:versionName="1.0" > 


<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="15" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 


<application 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" > 
    <activity 
     android:name=".ApplicationMain" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name=".JobList" 
     android:label="@string/app_name" > 
    </activity> 
</application> 

    </manifest> 

Answer 1

你忘了註冊活動的manifest.xml

<activity 
     android:name=".ExerciseList" 
     android:label="@string/app_name" > 
    </activity>