android应用程序不断崩溃“不幸的是，计算器已经停止”

mftmpeh8  于 2021-07-09  发布在  Java
关注(0)|答案(1)|浏览(454)

当我尝试运行以下代码时，会不断收到错误日志，并显示错误消息：

  1. 03-11 16:00:08.350: E/AndroidRuntime(842): FATAL EXCEPTION: main
  2. 03-11 16:00:08.350: E/AndroidRuntime(842): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.calculator/com.example.calculator.MainActivity}: java.lang.NumberFormatException: Invalid double: ""
  3. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
  4. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
  5. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
  6. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
  7. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.os.Handler.dispatchMessage(Handler.java:99)
  8. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.os.Looper.loop(Looper.java:137)
  9. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread.main(ActivityThread.java:5041)
  10. 03-11 16:00:08.350: E/AndroidRuntime(842):  at java.lang.reflect.Method.invokeNative(Native Method)
  11. 03-11 16:00:08.350: E/AndroidRuntime(842):  at java.lang.reflect.Method.invoke(Method.java:511)
  12. 03-11 16:00:08.350: E/AndroidRuntime(842):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
  13. 03-11 16:00:08.350: E/AndroidRuntime(842):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
  14. 03-11 16:00:08.350: E/AndroidRuntime(842):  at dalvik.system.NativeStart.main(Native Method)
  15. 03-11 16:00:08.350: E/AndroidRuntime(842): Caused by: java.lang.NumberFormatException: Invalid double: ""
  16. 03-11 16:00:08.350: E/AndroidRuntime(842):  at java.lang.StringToReal.invalidReal(StringToReal.java:63)
  17. 03-11 16:00:08.350: E/AndroidRuntime(842):  at java.lang.StringToReal.parseDouble(StringToReal.java:248)
  18. 03-11 16:00:08.350: E/AndroidRuntime(842):  at java.lang.Double.parseDouble(Double.java:295)
  19. 03-11 16:00:08.350: E/AndroidRuntime(842):  at com.example.calculator.MainActivity.onCreate(MainActivity.java:21)
  20. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.Activity.performCreate(Activity.java:5104)
  21. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
  22. 03-11 16:00:08.350: E/AndroidRuntime(842):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
  23. 03-11 16:00:08.350: E/AndroidRuntime(842):  ... 11 more
  24. 03-11 16:05:08.990: E/AndroidRuntime(959): FATAL EXCEPTION: main
  25. 03-11 16:05:08.990: E/AndroidRuntime(959): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.calculator/com.example.calculator.MainActivity}: java.lang.NumberFormatException: Invalid double: ""
  26. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
  27. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
  28. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
  29. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
  30. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.os.Handler.dispatchMessage(Handler.java:99)
  31. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.os.Looper.loop(Looper.java:137)
  32. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread.main(ActivityThread.java:5041)
  33. 03-11 16:05:08.990: E/AndroidRuntime(959):  at java.lang.reflect.Method.invokeNative(Native Method)
  34. 03-11 16:05:08.990: E/AndroidRuntime(959):  at java.lang.reflect.Method.invoke(Method.java:511)
  35. 03-11 16:05:08.990: E/AndroidRuntime(959):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
  36. 03-11 16:05:08.990: E/AndroidRuntime(959):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
  37. 03-11 16:05:08.990: E/AndroidRuntime(959):  at dalvik.system.NativeStart.main(Native Method)
  38. 03-11 16:05:08.990: E/AndroidRuntime(959): Caused by: java.lang.NumberFormatException: Invalid double: ""
  39. 03-11 16:05:08.990: E/AndroidRuntime(959):  at java.lang.StringToReal.invalidReal(StringToReal.java:63)
  40. 03-11 16:05:08.990: E/AndroidRuntime(959):  at java.lang.StringToReal.parseDouble(StringToReal.java:248)
  41. 03-11 16:05:08.990: E/AndroidRuntime(959):  at java.lang.Double.parseDouble(Double.java:295)
  42. 03-11 16:05:08.990: E/AndroidRuntime(959):  at com.example.calculator.MainActivity.onCreate(MainActivity.java:21)
  43. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.Activity.performCreate(Activity.java:5104)
  44. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
  45. 03-11 16:05:08.990: E/AndroidRuntime(959):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
  46. 03-11 16:05:08.990: E/AndroidRuntime(959):  ... 11 more

主活动.java

  1. package com.example.calculator;
  3. import android.os.Bundle;
  4. import android.app.Activity;
  5. import android.view.Menu;
  6. import android.widget.EditText;
  7. import android.widget.TextView;
  9. public class MainActivity extends Activity {
  11.     @Override
  12.     protected void onCreate(Bundle savedInstanceState) {
  13.         super.onCreate(savedInstanceState);
  14.         setContentView(R.layout.activity_main);
  16.         TextView tPrincipalAmount   = (TextView)findViewById(R.id.tPrincipalAmount);
  17.         EditText editPrincipalAmount= (EditText)findViewById(R.id.editPrincipalAmount);
  18.         String String_Principal_amount = editPrincipalAmount.getText().toString();
  19.         double DbPrincipalAmount = Double.parseDouble(String_Principal_amount);
  21.         TextView tInterestRate =(TextView) findViewById(R.id.tInterestRate);
  22.         EditText editInterestRate =(EditText) findViewById(R.id.editInterestRate);
  23.         String string_editInterestRate =editInterestRate.getText().toString();
  24.         double DbInterestRate = Double.parseDouble(string_editInterestRate);
  26.     }
  28. }

活动\u main.xml

  1. <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  2.     xmlns:tools="http://schemas.android.com/tools"
  3.     android:layout_width="match_parent"
  4.     android:layout_height="match_parent"
  5.     android:paddingBottom="@dimen/activity_vertical_margin"
  6.     android:paddingLeft="@dimen/activity_horizontal_margin"
  7.     android:paddingRight="@dimen/activity_horizontal_margin"
  8.     android:paddingTop="@dimen/activity_vertical_margin"
  9.     tools:context=".MainActivity" >
  11.     <TextView
  12.         android:id="@+id/tPrincipalAmount"
  13.         android:layout_width="wrap_content"
  14.         android:layout_height="wrap_content"
  15.         android:layout_alignParentLeft="true"
  16.         android:layout_alignParentTop="true"
  17.         android:layout_marginLeft="14dp"
  18.         android:text="Principal Amount ($)" />
  20.     <EditText
  21.         android:id="@+id/editPrincipalAmount"
  22.         android:layout_width="wrap_content"
  23.         android:layout_height="wrap_content"
  24.         android:layout_alignLeft="@+id/tPrincipalAmount"
  25.         android:layout_below="@+id/tPrincipalAmount"
  26.         android:ems="10" />
  28.     <TextView
  29.         android:id="@+id/tInterestRate"
  30.         android:layout_width="wrap_content"
  31.         android:layout_height="wrap_content"
  32.         android:layout_alignLeft="@+id/editPrincipalAmount"
  33.         android:layout_below="@+id/editPrincipalAmount"
  34.         android:layout_marginTop="26dp"
  35.         android:text="Interest Rate" />
  37.     <EditText
  38.         android:id="@+id/editInterestRate"
  39.         android:layout_width="wrap_content"
  40.         android:layout_height="wrap_content"
  41.         android:layout_alignParentLeft="true"
  42.         android:layout_below="@+id/tInterestRate"
  43.         android:layout_marginTop="27dp"
  44.         android:ems="10" />
  46. </RelativeLayout>

谢谢您

JavaandroidStringDoubleNumberFormatException

1条答案

按热度按时间
4urapxun

4urapxun1#

这个 string 要解析为 double 不包含一个值，这就是为什么您要 NumberFormatException . 你应该检查一下 string 包含有效值。现在，检查如下。。。

  1. @Override
  2. protected void onCreate(Bundle savedInstanceState) {
  3.     super.onCreate(savedInstanceState);
  4.     setContentView(R.layout.activity_main);
  6.     TextView tPrincipalAmount   = (TextView)findViewById(R.id.tPrincipalAmount);
  7.     EditText editPrincipalAmount= (EditText)findViewById(R.id.editPrincipalAmount);
  8.     String String_Principal_amount = editPrincipalAmount.getText().toString();
  9.     double DbPrincipalAmount = 0;
  11.     if (String_Principal_amount != null && !String_Principal_amount.equals("")) {
  13.         DbPrincipalAmount = Double.parseDouble(String_Principal_amount);
  15.     }
  17.     TextView tInterestRate =(TextView) findViewById(R.id.tInterestRate);
  18.     EditText editInterestRate =(EditText) findViewById(R.id.editInterestRate);
  19.     String string_editInterestRate =editInterestRate.getText().toString();
  21.     double DbInterestRate = 0;
  23.     if (string_editInterestRate != null && !string_editInterestRate.equals("")) {
  25.         DbInterestRate = Double.parseDouble(string_editInterestRate);
  27.      }
  29. }
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