嗨,所有米有一個奇怪的問題。按鈕ClickListener nullpointerexception android
我有一個按鈕,當我設置onClick監聽器。
它給我null指針異常和應用程序強行關閉。
我的代碼是
more = (Button) findViewById(R.id.moreButton);
System.out.println("BEFORE more listener CALL");
more.setOnClickListener(this);
它很奇怪,我請任何一個可以幫助?
堆棧跟蹤如下:
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): FATAL EXCEPTION: main
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.sigmatec.finditnear/org.sigmatec.finditnear.customListView}: java.lang.NullPointerException
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.os.Looper.loop(Looper.java:123)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at java.lang.reflect.Method.invokeNative(Native Method)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at java.lang.reflect.Method.invoke(Method.java:521)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at dalvik.system.NativeStart.main(Native Method)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): Caused by: java.lang.NullPointerException
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at org.sigmatec.finditnear.customListView.onCreate(customListView.java:114)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-17 13:28:54.141: ERROR/AndroidRuntime(1509): ... 11 more
更新:
一兩件事,我現在用的按鈕已經採取了從答案從鏈接
How to add a footer in ListView?
我已經使用按鈕代替TextView最後看一下回答#2。
m使用其他佈局中的Button而不是已經在setContentView上設置的佈局。因爲我使用列表,我想要一個按鈕在列表的末尾,所以我做了一個單獨的.xml,並使用下面的代碼與列表頁腳一起加入。
代碼:
super.onCreate(savedInstanceState);
setContentView(R.layout.listview);
ListView l1 = (ListView) findViewById(R.id.ListView01);
View footerView =
((LayoutInflater)this.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.layout_footer, null, false);
l1.addFooterView(footerView);
l1.setAdapter(adapter);
請發佈您的佈局和java文件 – Nikhil 2011-05-17 07:46:06