我试图清理我的监听器并出错了：我在LogCat中得到了一个典型的'NullPoinerException'，并且有下面的方法（第一次尝试这样做）。
有任何帮助吗？日Thnx！
活动：
public class List_RegulatoryDocs extends Activity {
OnClickListener myClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
if (v == acItem) {
Intent ACList = new Intent(List_RegulatoryDocs.this,
List_AC.class);
startActivity(ACList);
} else if (v == adItem) {
// TODO
}else if (v == cfrItem) {
// TODO
}//TODO + items
}
};
/**
* -- Called when the activity is first created
* ===================================================================
*/
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.regulatory_docs_list);
// Set the Click Listeners
acItem.setOnClickListener(myClickListener);
adItem.setOnClickListener(myClickListener);
cfrItem.setOnClickListener(myClickListener);
}
/**
* -- Local Variables
* =====================================================================
**/
RelativeLayout acItem = (RelativeLayout) findViewById(R.id.acItem);
RelativeLayout adItem = (RelativeLayout) findViewById(R.id.adItem);
RelativeLayout cfrItem = (RelativeLayout) findViewById(R.id.cfrItem);
// RelativeLayout pmaItem = (RelativeLayout) findViewById(R.id.pmaItem);
// RelativeLayout saibItem = (RelativeLayout) findViewById(R.id.saibItem);
// RelativeLayout sfarItem = (RelativeLayout) findViewById(R.id.sfarItem);
// RelativeLayout stcItem = (RelativeLayout) findViewById(R.id.stcItem);
// RelativeLayout tsoItem = (RelativeLayout) findViewById(R.id.tsoItem);
// RelativeLayout tcdsItem = (RelativeLayout) findViewById(R.id.tcdsItem);
}
logcat的：
05-05 01:27:29.931: WARN/dalvikvm(13268): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): FATAL EXCEPTION: main
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.aeroTechnologies.flyDroid/com.aeroTechnologies.flyDroid.regList.List_RegulatoryDocs}: java.lang.NullPointerException
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.os.Handler.dispatchMessage(Handler.java:99)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.os.Looper.loop(Looper.java:123)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at java.lang.reflect.Method.invokeNative(Native Method)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at java.lang.reflect.Method.invoke(Method.java:521)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at dalvik.system.NativeStart.main(Native Method)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): Caused by: java.lang.NullPointerException
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.Activity.findViewById(Activity.java:1637)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at com.aeroTechnologies.flyDroid.regList.List_RegulatoryDocs.<init>(List_RegulatoryDocs.java:51)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at java.lang.Class.newInstanceImpl(Native Method)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at java.lang.Class.newInstance(Class.java:1429)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): ... 11 more
答案 0 :(得分：3)
声明acItem，adItem，cfrItem（如果你愿意，可以作为成员变量） 然后在onCreate（）;
中分配它们 public class List_RegulatoryDocs extends Activity {
RelativeLayout acItem ;
RelativeLayout adItem;
RelativeLayout cfrItem ;
OnClickListener myClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
if (v == acItem) {
Intent ACList = new Intent(List_RegulatoryDocs.this,
List_AC.class);
startActivity(ACList);
} else if (v == adItem) {
// TODO
}else if (v == cfrItem) {
// TODO
}//TODO + items
}
};
/**
* -- Called when the activity is first created
* ===================================================================
*/
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.regulatory_docs_list);
acItem = (RelativeLayout) findViewById(R.id.acItem);
adItem = (RelativeLayout) findViewById(R.id.adItem);
cfrItem = (RelativeLayout) findViewById(R.id.cfrItem);
// Set the Click Listeners
acItem.setOnClickListener(myClickListener);
adItem.setOnClickListener(myClickListener);
cfrItem.setOnClickListener(myClickListener);
}
/**
* -- Local Variables
* =====================================================================
**/
// RelativeLayout pmaItem = (RelativeLayout) findViewById(R.id.pmaItem);
// RelativeLayout saibItem = (RelativeLayout) findViewById(R.id.saibItem);
// RelativeLayout sfarItem = (RelativeLayout) findViewById(R.id.sfarItem);
// RelativeLayout stcItem = (RelativeLayout) findViewById(R.id.stcItem);
// RelativeLayout tsoItem = (RelativeLayout) findViewById(R.id.tsoItem);
// RelativeLayout tcdsItem = (RelativeLayout) findViewById(R.id.tcdsItem);
}
答案 1 :(得分：2)
在onCreate中，您似乎正在访问acItem，adItem和cfrItem而未初始化它们。
答案 2 :(得分：0)
在onCreate中，您似乎在不初始化acItem，adItem和cfrItem的情况下访问它们。
做得好，对我有用