Java 致命异常，应用程序停止错误

我在logcat中遇到致命的异常错误，运行时应用程序正在停止

爪哇

xml

---

您需要检查字符串是否为空-否则无法从中解析整数：

if (x == 0 && !tt.getText().toString().isEmpty()){

    x = Integer.parseInt(tt.getText().toString());

}

---

您需要检查下一行中解析为int的字符串值是否为空

 if (x == 0){
    if(null != tt.getText().toString() && !"".equals(tt.getText().toString().trim())){
         x = Integer.parseInt(tt.getText().toString());
    }

}

---

希望这有帮助

现在应用程序正在运行。但是得到ans=0。我的逻辑有问题吗

10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: FATAL EXCEPTION: main 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: Process: com.example.parth.editcal, PID: 17077 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.parth.editcal/com.example.parth.editcal.MainActivity}: java.lang.NumberFormatException: Invalid int: "" 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2548) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2607) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.access$900(ActivityThread.java:174) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1325) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.os.Looper.loop(Looper.java:146) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5756) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:515) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: Caused by: java.lang.NumberFormatException: Invalid int: "" 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.Integer.invalidInt(Integer.java:137) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.Integer.parseInt(Integer.java:358) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.Integer.parseInt(Integer.java:331) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at com.example.parth.editcal.MainActivity.onCreate(MainActivity.java:190) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:5619) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2512) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2607) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.access$900(ActivityThread.java:174) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1325) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.os.Looper.loop(Looper.java:146) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5756) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:515) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107) 10-27 22:36:08.318 17077-17077/com.example.parth.editcal E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)

if (x == 0 && !tt.getText().toString().isEmpty()){

    x = Integer.parseInt(tt.getText().toString());

}

 if (x == 0){
    if(null != tt.getText().toString() && !"".equals(tt.getText().toString().trim())){
         x = Integer.parseInt(tt.getText().toString());
    }

}