模拟器一进去就退出来 真机也不行

Question

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: cn.itcast.myqq, PID: 13051
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.itcast.myqq/cn.itcast.myqq.MyQQ}: java.lang.ClassCastException: android.support.v7.widget.AppCompatButton cannot be cast to android.widget.EditText
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2727)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2788)
                      at android.app.ActivityThread.-wrap12(ActivityThread.java)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1512)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6209)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:790)
                   Caused by: java.lang.ClassCastException: android.support.v7.widget.AppCompatButton cannot be cast to android.widget.EditText
                      at cn.itcast.myqq.MyQQ.initView(MyQQ.java:33)
                      at cn.itcast.myqq.MyQQ.onCreate(MyQQ.java:23)
                      at android.app.Activity.performCreate(Activity.java:6815)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1125)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2680)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2788) 
                      at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1512) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6209) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:790) 
Application terminated.

Answer 1

 cn.itcast.myqq.MyQQ.initView  里面你把一个AppCompatButton资源赋值给EditText对象了

Answer 2

Caused by: java.lang.ClassCastException:
 android.support.v7.widget.AppCompatButton cannot be cast to android.widget.EditText
 at cn.itcast.myqq.MyQQ.initView(MyQQ.java:33)这个报错提示已经很清楚了，在MyQQ.java这个文件的第33行，你把.AppCompatButton当作EditText来初始化，导致了类型转换错误，即 java.lang.ClassCastException:

Answer 3

 java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.itcast.myqq/cn.itcast.myqq.MyQQ}: java.lang.ClassCastException: android.support.v7.widget.AppCompatButton cannot be cast to android.widget.EditText
AppCompatButton 对象无法强制转换为EditText对象
  at cn.itcast.myqq.MyQQ.initView(MyQQ.java:33)
错误位置在MyQQ.java的33行建议LZ多自己看看...很容易读出来的啊....你这是获取的你的XML里面的BUTTON但是却强制转换为了EditText