在Android的多种活动与3 Activites [英] Multiple Activities in Android with 3 Activites

问题描述

我创建多个活动在Android中，这是我的logcat错误输出。

I am creating multiple activities in Android, this is my logcat error output.

log.txt中

05-03 03:17:23.295: E/PhonePolicy(1854): Could not preload class for phone policy: com.android.internal.policy.impl.PhoneWindow$ContextMenuCallback
05-03 03:17:37.044: W/dalvikvm(1854): threadid=1: thread exiting with uncaught exception (group=0x409db1f8)
05-03 03:17:37.044: E/AndroidRuntime(1854): FATAL EXCEPTION: main
05-03 03:17:37.044: E/AndroidRuntime(1854): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.jumoun.itemp/com.jumoun.itemp.Converter}: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.os.Looper.loop(Looper.java:137)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread.main(ActivityThread.java:4427)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at java.lang.reflect.Method.invokeNative(Native Method)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at java.lang.reflect.Method.invoke(Method.java:511)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at dalvik.system.NativeStart.main(Native Method)
05-03 03:17:37.044: E/AndroidRuntime(1854): Caused by: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button
05-03 03:17:37.044: E/AndroidRuntime(1854):     at com.jumoun.itemp.Converter.onCreate(Converter.java:41)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.Activity.performCreate(Activity.java:4465)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
05-03 03:17:37.044: E/AndroidRuntime(1854):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
05-03 03:17:37.044: E/AndroidRuntime(1854):     ... 11 more
05-03 03:17:38.704: I/Process(1854): Sending signal. PID: 1854 SIG: 9

这是我的Java文件 Converter.java http://pastebin.com/VNNPy7D5

This is my java file Converter.java http://pastebin.com/VNNPy7D5

感谢球员：）

推荐答案

如果我算这个权

ibHome3 = (Button) findViewById(R.id.ibHome3);

是造成你的问题。你必须把它作为你的Java声明的的ImageButton 在你的XML，但按钮。只需将其更改为

is causing your problem. You have it as an ImageButton in your xml but Button in your java declaration. Just change it to

ImageButton ibHome3;

关于logcat的

此外，在logcat的只是一个小建议。如果您发现的第一行写着所引发在致命异常您可以跟踪您的问题更容易。这是

Also, just a little advice on logcat. If you find the first line that says Caused By after Fatal Exception you can track down your problem easier. Here it is

 Caused by: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button

这给出了异常

java.lang.ClassCastException

然后找到后它引用你的包的第一行。在这里，

then find the first line after that which references your package. Here

at com.jumoun.itemp.Converter.onCreate(Converter.java:41)

这告诉我们，这个问题在41线开始于 Converter.java

this tells us the problem starts in Converter.java at line 41

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