android.content.ContextWrapper.getPackageName ANDROID 处的 java.lang.NullPointerException

嘿，我想从 MainActivity 启动一个 Activity，但不是在 oncreate 方法中启动。

public void awe()
{
    Intent myIntent = new Intent(MainActivity.this, Awesome.class);
    MainActivity.this.startActivity(myIntent);
}

另一个类调用方法 awe() ，我得到的是崩溃并且

05-25 04:06:51.034: E/AndroidRuntime(7161): FATAL EXCEPTION: main
05-25 04:06:51.034: E/AndroidRuntime(7161): java.lang.NullPointerException
05-25 04:06:51.034: E/AndroidRuntime(7161):     at android.content.ContextWrapper.getPackageName(ContextWrapper.java:151)
05-25 04:06:51.034: E/AndroidRuntime(7161):     at android.content.ComponentName.<init>(ComponentName.java:106)
05-25 04:06:51.034: E/AndroidRuntime(7161):     at android.content.Intent.<init>(Intent.java:2895)
05-25 04:06:51.034: E/AndroidRuntime(7161):     at package name.MainActivity.awe(MainActivity.java:215)

有人知道我能做什么吗？

主要活动

public class MainActivity extends Activity implements OnClickListener { 
// (variable stuff)
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

          buttonE = (Button) findViewById(R.id.buttonEASY); 
          buttonM = (Button) findViewById(R.id.buttonMED);

// here I do all that button stuff for the layout
}



    public void onClick(View arg0) {
        System.out.println("click");
        if (arg0==buttonE)  {

                 int checkedRadioButton = radioGroup1.getCheckedRadioButtonId();
                                 String radioButtonSelected = "";

                                 switch (checkedRadioButton) {

                                  case R.id.radio0 : radioButtonSelected = "radiobutton1";
                                  Toast.makeText(getApplicationContext(), "Easy, 10 selected", Toast.LENGTH_SHORT).show();
                                  setContentView(R.layout.raten);

// Button stuff, again.


}



public void awe()
{   Intent tutorial = new Intent(MainActivity.this, Awesome.class); 
    if (tutorial != null) { startActivity(tutorial); } 

}

Easy.java

这里没什么重要的，就是我提到 awe() 的地方：

if (s==max+1){System.out.println("AWESOME!"); MainActivity mA = new MainActivity(); mA.awe();}

很棒的.java

public class Awesome extends Activity {

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

我希望我现在发布了所有重要的内容

问题可能是，当您调用 awe() 方法时，MainActivity 尚未完全初始化，并且 Activity 的内部 Context 为 null。