单击按钮时应用程序崩溃

Question

我正在制作一个应用程序，其中包含三个 editText 和一个按钮。我正在做的是在 EditText 中获取一些输入，进行计算，然后按下按钮转到另一个 activity.

我的问题是当我不输入任何值并按下按钮时应用程序崩溃这是我的代码-

     btn.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {

            Double x  = Double.parseDouble(editText1.getText().toString());

            try{

            if(x == null || x.equals("")){

                Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                  return;
            }else{

            }
            }
                catch(Exception e){
                    Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                }

            Double y  = Double.parseDouble(editText2.getText().toString());

            try{

                if(y == null || y.equals("")){

                    Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                      return;
                }else{

                }
                }
                    catch(Exception e){
                        Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                    }


            Double z  = Double.parseDouble(editText3.getText().toString());

            try{

                if(z == null || z.equals("")){

                    Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                      return;
                }else{

                }
                }
                    catch(Exception e){
                        Toast.makeText(getApplicationContext(), "Insert All The Fields", Toast.LENGTH_LONG).show();
                    }

            i = x+y+z;

            Intent intent = new Intent(getApplicationContext(),SecondActivity.class);
            intent.putExtra("key", +i);
            startActivity(intent);

这是 Logcat

01-04 05:43:20.342: E/AndroidRuntime(1814): FATAL EXCEPTION: main
01-04 05:43:20.342: E/AndroidRuntime(1814): Process: com.example.calculatorpd, PID: 1814
01-04 05:43:20.342: E/AndroidRuntime(1814): java.lang.NumberFormatException: Invalid double: ""
01-04 05:43:20.342: E/AndroidRuntime(1814):     at java.lang.StringToReal.invalidReal(StringToReal.java:63)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at java.lang.StringToReal.parseDouble(StringToReal.java:248)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at java.lang.Double.parseDouble(Double.java:295)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at com.example.calculatorpd.MainActivity.onClick(MainActivity.java:76)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.view.View.performClick(View.java:4438)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.view.View$PerformClick.run(View.java:18422)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.os.Handler.handleCallback(Handler.java:733)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.os.Handler.dispatchMessage(Handler.java:95)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.os.Looper.loop(Looper.java:136)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at android.app.ActivityThread.main(ActivityThread.java:5017)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at java.lang.reflect.Method.invokeNative(Native Method)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at java.lang.reflect.Method.invoke(Method.java:515)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
01-04 05:43:20.342: E/AndroidRuntime(1814):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

问题是您正在解析一些空文本。因此，在执行导致异常的双重解析之前，首先检查文本本身。

     btn.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {

           Double x, y,z;

            try
            {
             String a = editText1.getText().toString();

             if(a == null || a.equals(""))
             {
                 x = 0;
                 Toast.makeText(getApplicationContext(), 
                 "Insert All The Fields", Toast.LENGTH_LONG).show();
                  return;
            }
            else
            {
              x  = Double.parseDouble(a);
            }
            }
                catch(Exception e){
                    Toast.makeText(getApplicationContext(), 
                    "Insert All The Fields", Toast.LENGTH_LONG).show();
                }



            try{

                 String b = editText2.getText().toString();

               if(b == null || b.equals(""))
             {
                    y = 0;
                    Toast.makeText(getApplicationContext(), 
                    "Insert All The Fields", Toast.LENGTH_LONG).show();
                      return;
                }else{
                 y  = Double.parseDouble(editText2.getText().toString());
                }
                }
                    catch(Exception e){
                        Toast.makeText(getApplicationContext(), 
                        "Insert All The Fields", Toast.LENGTH_LONG).show();
                    }




            try{
                 String c = editText3.getText().toString();

               if(c == null || c.equals(""))
             {

                    z = 0;
                    Toast.makeText(getApplicationContext(), 
                    "Insert All The Fields", Toast.LENGTH_LONG).show();
                      return;
                }else{
                   z  = Double.parseDouble(editText3.getText().toString());
                }
                }
                    catch(Exception e){
                        Toast.makeText(getApplicationContext(), 
                        "Insert All The Fields", Toast.LENGTH_LONG).show();
                    }

            i = x +y+z;
            Intent intent = new Intent(getApplicationContext(),SecondActivity.class);
            intent.putExtra("key", +i);
            startActivity(intent);

Answer 2

在你使用这条线之前

Double x  = Double.parseDouble(editText1.getText().toString());

您需要检查该字符串是否代表数字。

    if(editText1.getText().toString() == null || editText1.getText().toString().equals("")){

        Toast.makeText(getApplicationContext(), 
        "Insert All The Fields", Toast.LENGTH_LONG).show();
          return;
     }else{
             Double x  = Double.parseDouble(editText1.getText().toString());
     }

您需要添加更多测试来验证这只是一个数字

单击按钮时应用程序崩溃

Application crash on Button clicked

android