AlertDialog强制关闭EditText

Question

我收到了错误：

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.crmdev.circuitorlcparalelo, PID: 6778
              java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
                  at com.crmdev.circuitorlcparalelo.MainActivity$3.onClick(MainActivity.java:70)
                  at android.support.v7.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
                  at android.os.Handler.dispatchMessage(Handler.java:106)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6626)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)

对于具有AlertDialog的以下代码：

AlertDialog.Builder result = new AlertDialog.Builder(MainActivity.this);
        result.setTitle("Iterações");
        result.setMessage("Digite o número de iterações desejadas: ");
        final EditText iteracoes = new EditText(this);
        iteracoes.setInputType(InputType.TYPE_CLASS_NUMBER);
        iteracoes.setGravity(9);
        iteracoes.setPadding(10,10,10,10);
        result.setView(iteracoes);
        result.setPositiveButton("Calcular", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                if(iteracoes.getText().equals("")){
                    Toast.makeText(getApplicationContext(), "Digite algum valor para as iterações!", Toast.LENGTH_LONG).show();
                    iteracoes.setText("");
                }
                else{
                    //Pega o numero de iterações
                    iteracao = Integer.getInteger(iteracoes.getText().toString());

                    tensaof = onCalculo(iteracao);

                    Bundle dad = new Bundle();
                    dad.putDouble("resultado", tensaof);
                    Intent intent = new Intent(MainActivity.this, ResultActivity.class);
                    intent.putExtras(dad);
                    startActivity(intent);
                }
            }
        });
        result.show();

每当我按下按钮Calcular应用程序强制关闭，我更改功能onCalculo但继续相同的方式。当onCalculo函数只改变了TextView时，应用程序没有这个问题。我看不出有什么问题。谢谢。

Answer 1

因为你使用错误的方法从String解析为Integer。你应该

iteracao = Integer.parseInt(iteracoes.getText().toString());

代替

iteracao = Integer.getInteger(iteracoes.getText().toString());

顺便说一句qazxsw poi方法可能抛出qazxsw poi所以你应该放入一个parseInt块以防止应用程序崩溃。

NumberFormatException