java - 局部变量可能尚未初始化-Android项目

过去几天，我一直在使用Android计算器。我已经到达了equals按钮，这是代码的最后一部分。但是，这是因为我的if语句出于某种原因未初始化theOperator。有什么帮助吗？

[码]
    包rechee.cool;

import android.app.Activity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;




public class HelloAndroidActivity extends Activity {
    /** Called when the activity is first created. */
     public EditText display;

    double counter1=0;
    double counter2=0;

    String display1= display.getText().toString();


    String sub = "-";
    String divide = "/";

    String mult = "*";


    //Just have two buttons so far, I'm going to have like 10 more







    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // Associate the button variable with the xml reference



        display= (EditText) findViewById(R.id.editText1);}




        //When button is clicked, display the text. How do I do this for the rest of my variables?


            public void onClick(View v) {
                switch(v.getId()){
                    case R.id.bOne:
                    display.append("1");
                        break;
                    case R.id.bTwo:

                        display.append("2");
                        break;
                    case R.id.bThree:
                        display.append("3");
                        break;
                    case R.id.bFour:
                        display.append("4");
                        break;
                    case R.id.bFive:
                        display.append("5");
                        break;
                    case R.id.bSix:
                        display.append("6");
                        break;

                    case R.id.bSeven:
                        display.append("7");
                        break;
                    case R.id.bEight:
                        display.append("8");
                        break;
                    case R.id.bNine:
                        display.append("9");
                        break;
                    case R.id.bZero:
                        display.append("0");
                        break;
                    case R.id.bPoint:
                        display.append(".");
                        break;
                    case R.id.bClear:
                        display.setText("");
                        break;
                    case R.id.bAdd:
                    double displayValue= Double.parseDouble(display1);
                        counter1+= displayValue;
                        display.setText("");
                        String theOperator= new String("+");




                        break;
                    case R.id.bEqual:

                        //display.setText(Double.toString(counter2));
                        //counter1 = 0;
                        // Tried using a switch for theOperator, but 1.6 doesn't allow string switch. So I'm going to use if else statements instead.
                        if(theOperator=="+"){



                        }

                        }
                        //case "+":
                    //break;





                        }





                }

[/码]

最佳答案

这是因为仅在theOperator范围内定义case R.id.bAdd，而case R.id.bEqual块看不到它。您可以通过在整个开关块之外或作为整个类的字段定义变量theOperator来解决问题。