做activity跳转 怎么报错了。。。

[金黄金黄即可]

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.uiceshi/com.example.uiceshi.MainActivity}: java.lang.NullPointerException

配置

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/ArrayAdapter" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

<activity
android:name=".mListView"
android:label="mListView" >/</activity>
</application>

第一个activity
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mButton.setOnClickListener(this);

}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent();
intent.setClass(MainActivity.this, mListView.class);
startActivity(intent);

第二个
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
listView = new ListView(this);
listView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_expandable_list_item_1, getData()));
setContentView(listView);
}

[依然绿茶]

mButton.setOnClickListener(this); 楼主是这句报空指针异常吧？ 你这里mButton都还没有实例化，把上面那句前面加一句 Button mButton = (Button) findViewById(R.id.button); mButton.setOnClickListener(this);

[金黄金黄即可]

引用 1 楼 ncepu307 的回复:

mButton.setOnClickListener(this); 楼主是这句报空指针异常吧？ 你这里mButton都还没有实例化，把上面那句前面加一句 Button mButton = (Button) findViewById(R.id.button); mButton.setOnClickListener(this);

。。。。我说找半天没错啊。。。。