安卓eclipse 空指针错误

Question

java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.itcast.smssender/cn.itcast.smssender.SelectContactActivity}: java.lang.NullPointerException

07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread.access$800(ActivityThread.java:135)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.os.Handler.dispatchMessage(Handler.java:102)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.os.Looper.loop(Looper.java:136)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread.main(ActivityThread.java:5017)
07-27 22:44:34.566: E/AndroidRuntime(2117): at java.lang.reflect.Method.invokeNative(Native Method)
07-27 22:44:34.566: E/AndroidRuntime(2117): at java.lang.reflect.Method.invoke(Method.java:515)
07-27 22:44:34.566: E/AndroidRuntime(2117): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
07-27 22:44:34.566: E/AndroidRuntime(2117): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
07-27 22:44:34.566: E/AndroidRuntime(2117): at dalvik.system.NativeStart.main(Native Method)
07-27 22:44:34.566: E/AndroidRuntime(2117): Caused by: java.lang.NullPointerException
07-27 22:44:34.566: E/AndroidRuntime(2117): at cn.itcast.smssender.SelectContactActivity$MyAdapter.getCount(SelectContactActivity.java:32)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.widget.ListView.setAdapter(ListView.java:480)
07-27 22:44:34.566: E/AndroidRuntime(2117): at cn.itcast.smssender.SelectContactActivity.onCreate(SelectContactActivity.java:26)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.Activity.performCreate(Activity.java:5231)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
07-27 22:44:34.566: E/AndroidRuntime(2117): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
07-27 22:44:34.566: E/AndroidRuntime(2117): ... 11 more
![

lv也没啥问题啊 说是空指针 网上说 布局定义的时候以前是android::name 改成id就行了 我本来就是ID啊求大神看看咋回事 改了半天也不成

Answer 1

07-27 22:44:34.566: E/AndroidRuntime(2117): at cn.itcast.smssender.SelectContactActivity$MyAdapter.getCount(SelectContactActivity.java:32)

是这一行发生了错误，并一定在布局里面！一般发生这样的情况就是你在这句代码里面“”.前面的变量空了“”，你看一下你的代码是不是没有给到值，或者就是单词写错！或许会对你有所帮助吧