Android中的小项目

将文本字段的值转换三次：

07-31 14:27:35.558: ERROR/AndroidRuntime(375): FATAL EXCEPTION: main
07-31 14:27:35.558: ERROR/AndroidRuntime(375): java.lang.NumberFormatException: unable to parse '' as integer
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.Integer.parseInt(Integer.java:412)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.Integer.parseInt(Integer.java:382)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.ExtraCharge.Calc.onClick(Calc.java:744)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.view.View.performClick(View.java:2408)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.view.View$PerformClick.run(View.java:8816)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Handler.handleCallback(Handler.java:587)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Handler.dispatchMessage(Handler.java:92)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Looper.loop(Looper.java:123)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.app.ActivityThread.main(ActivityThread.java:4627)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.reflect.Method.invokeNative(Native Method)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.reflect.Method.invoke(Method.java:521)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at dalvik.system.NativeStart.main(Native Method)

你为什么这么做？这不会很好，因为如果temp_val持有一个双精度，那么temp_val1将持有一个双精度，最后一次对话将失败。事情就是这样，但是：

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事实上，temp_val1包含一个空字符串，这就是在上一次对话中引发异常的原因。

请格式化源代码，以便我们可以阅读它！为什么要回滚格式化编辑？

07-31 14:27:35.558: ERROR/AndroidRuntime(375): FATAL EXCEPTION: main
07-31 14:27:35.558: ERROR/AndroidRuntime(375): java.lang.NumberFormatException: unable to parse '' as integer
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.Integer.parseInt(Integer.java:412)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.Integer.parseInt(Integer.java:382)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.ExtraCharge.Calc.onClick(Calc.java:744)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.view.View.performClick(View.java:2408)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.view.View$PerformClick.run(View.java:8816)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Handler.handleCallback(Handler.java:587)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Handler.dispatchMessage(Handler.java:92)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.os.Looper.loop(Looper.java:123)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at android.app.ActivityThread.main(ActivityThread.java:4627)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.reflect.Method.invokeNative(Native Method)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at java.lang.reflect.Method.invoke(Method.java:521)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-31 14:27:35.558: ERROR/AndroidRuntime(375):     at dalvik.system.NativeStart.main(Native Method)

   temp_val = Double.parseDouble(et1.getText().toString());
   ...
   String temp_val1=Double.toString(temp_val);
   wbval = Integer.parseInt(temp_val1);