Question

写了一个简单的登陆启动android客户端就出现如下的错误提示

08-13 01:42:56.453: E/Trace(1399): error opening trace file: No such file or directory (2)
08-13 01:42:57.233: D/AndroidRuntime(1399): Shutting down VM
08-13 01:42:57.233: W/dalvikvm(1399): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
08-13 01:42:57.263: E/AndroidRuntime(1399): FATAL EXCEPTION: main
08-13 01:42:57.263: E/AndroidRuntime(1399): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.wuliu/com.example.wuliu.Login}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread.access$600(ActivityThread.java:141)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.os.Handler.dispatchMessage(Handler.java:99)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.os.Looper.loop(Looper.java:137)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread.main(ActivityThread.java:5041)
08-13 01:42:57.263: E/AndroidRuntime(1399): at java.lang.reflect.Method.invokeNative(Native Method)
08-13 01:42:57.263: E/AndroidRuntime(1399): at java.lang.reflect.Method.invoke(Method.java:511)
08-13 01:42:57.263: E/AndroidRuntime(1399): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-13 01:42:57.263: E/AndroidRuntime(1399): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-13 01:42:57.263: E/AndroidRuntime(1399): at dalvik.system.NativeStart.main(Native Method)
08-13 01:42:57.263: E/AndroidRuntime(1399): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
08-13 01:42:57.263: E/AndroidRuntime(1399): at com.example.wuliu.Login.onCreate(Login.java:68)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.Activity.performCreate(Activity.java:5104)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
08-13 01:42:57.263: E/AndroidRuntime(1399): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
08-13 01:42:57.263: E/AndroidRuntime(1399): ... 11 more

Answer 1

看看这一句：java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText。类型强转时出问题了，你得到的View 是TextView，可是你却把强转成EditText，你是不是在findviewbyid的时候把EditText当成TextView 了？如果确定没有错，就清理一下工程：菜单样中 项目-->清理。

Answer 2

好像是你获取控件出错了， 把 textview 按照 editview 来进行获取了，你检查一下 看看

Answer 3

Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText 你Textview这个控件用的有误，检查下