Question

我尝试创建一个猜数游戏，我设置了一系列数字和编辑文本供用户输入数字。我试图输入，例如＆＃34; 50＆＃34;但是当我试图删除时，我只能删除＆＃34; 0＆＃34;。如果我继续删除号码＆＃34; 5＆＃34;该应用程序崩溃了。以下是我的MainActivity代码：

import java.util.Random;

public class MainActivity extends AppCompatActivity {
  TextView textViewChoice, textViewStatus;
  EditText editTextNum ;

Button buttonSetting;
SharedPreferences preferences;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    textViewChoice = (TextView) findViewById(R.id.textViewChoice);
    textViewStatus =(TextView) findViewById(R.id.textviewStatus);
    editTextNum = (EditText) findViewById(R.id.edittextGuess);

    buttonSetting =(Button) findViewById(R.id.buttonSetting);
    preferences = getSharedPreferences("LIMITS",MODE_PRIVATE);




    buttonSetting.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(MainActivity.this, SecondaryActivity.class);
            startActivity(intent);
        }
    });
}

@Override
protected void onStart() {
    super.onStart();
    final int MinNumber = preferences.getInt("Seekbar Min", 0);
    final int MaxNumber = preferences.getInt("Seekbar Max", 0);
    textViewChoice.setText("" + MinNumber + "-" + MaxNumber);

    editTextNum.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            Random random = new Random();
            int RanNum = random.nextInt(MaxNumber-MinNumber)+MinNumber;
            String StringEditNum= editTextNum.getText().toString();
            int EditNum = Integer.parseInt(StringEditNum);
            if (EditNum >RanNum){
                textViewStatus.setText("Enter Higher Number");
            }
            else if(EditNum <RanNum){
                textViewStatus.setText("Enter Lower Numer!");


            }
            else if (StringEditNum.equals("")){
                Toast.makeText(MainActivity.this,"Error!",Toast.LENGTH_SHORT).show();
            }
            else {
                textViewStatus.setText("You won! You Nutz!");
            }

        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    });

}

@Override
protected void onStop() {
    super.onStop();
}

@Override
protected void onDestroy() {
    super.onDestroy();
}
}

我调试后得到这个：

E / AndroidRuntime：致命异常：主要处理：com.example.user.ggame，PID：3291 java.lang.NumberFormatException：对于输入字符串：＆＃34;＆＃34; 在java.lang.Integer.parseInt（Integer.java:620）在java.lang.Integer.parseInt（Integer.java:643） at com.example.user.ggame.MainActivity $ 2.onTextChanged（MainActivity.java:71）在android.widget.TextView.sendOnTextChanged（TextView.java:9359）在android.widget.TextView.handleTextChanged（TextView.java:9446）在android.widget.TextView $ ChangeWatcher.onTextChanged（TextView.java:11904）在android.text.SpannableStringBuilder.sendTextChanged（SpannableStringBuilder.java:1252）在android.text.SpannableStringBuilder.replace（SpannableStringBuilder.java:573）在android.text.SpannableStringBuilder.delete（SpannableStringBuilder.java:229）在android.text.SpannableStringBuilder.delete（SpannableStringBuilder.java:227）在android.text.method.BaseKeyListener.backspaceOrForwardDelete（BaseKeyListener.java:370）在android.text.method.BaseKeyListener.backspace（BaseKeyListener.java:71）在android.text.method.BaseKeyListener.onKeyDown（BaseKeyListener.java:479）在android.text.method.NumberKeyListener.onKeyDown（NumberKeyListener.java:148）在android.widget.TextView.doKeyDown（TextView.java:7316）在android.widget.TextView.onKeyDown（TextView.java:7093）在android.view.KeyEvent.dispatch（KeyEvent.java:2688）在android.view.View.dispatchKeyEvent（View.java:11662）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在android.view.ViewGroup.dispatchKeyEvent（ViewGroup.java:1827）在com.android.internal.policy.DecorView.superDispatchKeyEvent（DecorView.java:437）在com.android.internal.policy.PhoneWindow.superDispatchKeyEvent（PhoneWindow.java:1818）在android.app.Activity.dispatchKeyEvent（Activity.java:3252）在android.support.v7.app.AppCompatActivity.dispatchKeyEvent（AppCompatActivity.java:534）在android.support.v7.view.WindowCallbackWrapper.dispatchKeyEvent（WindowCallbackWrapper.java:58）在android.support.v7.app.AppCompatDelegateImplBase $ AppCompatWindowCallbackBase.dispatchKeyEvent（AppCompatDelegateImplBase.java:316）在com.android.internal.policy.DecorView.dispatchKeyEvent（DecorView.java:351）在android.view.ViewRootImpl $ ViewPostImeInputStage.processKeyEvent（ViewRootImpl.java:4714）在android.view.ViewRootImpl $ ViewPostImeInputStage.onProcess（ViewRootImpl.java:4586）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:4128）在android.view.ViewRootImpl $ InputStage.onDeliverToNext（ViewRootImpl.java:4181）在android.view.ViewRootImpl $ InputStage.forward（ViewRootImpl.java:4147）在android.view.ViewRootImpl $ AsyncInputStage.forward（ViewRootImpl.java:4274）在android.view.ViewRootImpl $ InputStage.apply（ViewRootImpl.java:4155）在android.view.ViewRootImpl $ AsyncInputStage.apply（ViewRootImpl.java:4331）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:4128）在android.view.ViewRootImpl $ InputStage.onDeliverToNext（ViewRootImpl.java:4181）在android.view.ViewRootImpl $ InputStage.forward（ViewRootImpl.java:4147）在android.view.ViewRootImpl $ InputStage.apply（ViewRootImpl.java:4155）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:4128）在android.view.ViewRootImpl $ InputStage.onDeliverToNext（ViewRootImpl.java:4181）在android.view.ViewRootImpl $ InputStage.forward（ViewRootImpl.java:4147）在android.view.ViewRootImpl $ AsyncInputStage.forward（ViewRootImpl.java:4307）在android.view.ViewRootImpl $ ImeInputStage.onFinishedInputEvent（ViewRootImpl.java:4468）在android.view.inputmethod.InputMethodManager $ PendingEvent.run（InputMethodManager.java:2435）在android.view.inputmethod.InputMethodManager.invokeFinishedInputEventCallback（InputMethodManager.java:1998） E / AndroidRuntime：在android.view.inputmethod.InputMethodManager.finishedInputEvent（InputMethodManager.java:1989）在android.view.inputmethod.InputMethodManager $ ImeInputEventSender.onInputEventFinished（InputMethodManager.java:2412）在android.view.InputEventSender.dispatchInputEventFinished（InputEventSender.java:141）在android.os.MessageQueue.nativePollOnce（本机方法）在android.os.MessageQueue.next（MessageQueue.java:325）在android.os.Looper.loop（Looper.java:142）在android.app.ActivityThread.main（ActivityThread.java:6541） at java.lang.reflect.Method.invoke（Native Method）在com.android.internal.os.Zygote $ MethodAndArgsCaller.run（Zygote.java:240）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:767）

Answer 1

你的问题在这一行：

add###

虽然清除String StringEditNum= editTextNum.getText().toString(); int EditNum = Integer.parseInt(StringEditNum); 5的值将为空字符串，但您无法解析空字符串以使其崩溃

尝试添加：

StringEditNum

Answer 2

检查以下代码。

editTextNum.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

      if(editTextNum.getText().toString().length() > 0)
      {
        Random random = new Random();
        int RanNum = random.nextInt(MaxNumber-MinNumber)+MinNumber;
        String StringEditNum= editTextNum.getText().toString();
        int EditNum = Integer.parseInt(StringEditNum);
        if (EditNum >RanNum){
            textViewStatus.setText("Enter Higher Number");
        }
        else if(EditNum <RanNum){
            textViewStatus.setText("Enter Lower Numer!");
        }
        else if (StringEditNum.equals("")){
            Toast.makeText(MainActivity.this,"Error!",Toast.LENGTH_SHORT).show();
        }
        else {
            textViewStatus.setText("You won! You Nutz!");
        }
      }
    }

    @Override
    public void afterTextChanged(Editable editable) {

    }
});

Answer 3

尝试以下代码

   Random random = new Random();
   int RanNum = random.nextInt(MaxNumber-MinNumber)+MinNumber;
   String StringEditNum= editTextNum.getText().toString();
    if(!StringEditNum.equals("")){
        int EditNum = Integer.parseInt(StringEditNum);
        if (EditNum >RanNum){
            textViewStatus.setText("Enter Higher Number");
        }else if(EditNum <RanNum){
            textViewStatus.setText("Enter Lower Numer!");
        }else {
            textViewStatus.setText("You won! You Nutz!");
        }
    } else{
            Toast.makeText(MainActivity.this,"Try again!",Toast.LENGTH_SHORT).show();
        }

Answer 4

试试这个

这会产生java.lang.IllegalArgumentException: n <= 0: 0，因为绑定应该是random.nextInt(bound) 0＆lt; = bound

   Random random = new Random();
   int RanNum = random.nextInt(MaxNumber-MinNumber)+MinNumber;

   try this

    Random random = new Random();
    int RanNum = random.nextInt((MaxNumber-MinNumber)+1);

2.转换为整数

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        Random random = new Random();
        int RanNum = random.nextInt((MaxNumber-MinNumber)+1);
        String StringEditNum= editTextNum.getText().toString();
            if (!TextUtils.isEmpty(editTextNum.getText().toString()))
            {
                int EditNum = Integer.parseInt(StringEditNum);
                if (EditNum >RanNum){
                    textViewStatus.setText("Enter Higher Number");
                }
                else if(EditNum <RanNum){
                    textViewStatus.setText("Enter Lower Numer!");


                }
                else if (StringEditNum.equals("")){
                    Toast.makeText(MainActivity.this,"Error!",Toast.LENGTH_SHORT).show();
                }
                else {
                    textViewStatus.setText("You won! You Nutz!");
                }
            }else {

            }            

    }

Answer 5

检查 StringEditNum 非空或空，然后再将其转换为 int

    if(!StringEditNum.equalsIgnoreCase("")){

            int EditNum = Integer.parseInt(StringEditNum);

    }

Answer 6

问题是你正在使用textWatcher监听器，每当你编写/删除这个监听器的东西时。现在，当你写出数字50时，你写了5和0.然后当你删除它时，你先删除0，然后留下5.在这种情况下，以下行是好的

int EditNum = Integer.parseInt(StringEditNum);

但是当你删除5时，StringEditNum变为“”，上面的行将导致java.lang.NumberFormatException。所以请检查下面的代码，使其完美运作

import java.util.Random;

public class MainActivity extends AppCompatActivity {
TextView textViewChoice, textViewStatus;
EditText editTextNum ;

Button buttonSetting;
SharedPreferences preferences;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

textViewChoice = (TextView) findViewById(R.id.textViewChoice);
textViewStatus =(TextView) findViewById(R.id.textviewStatus);
editTextNum = (EditText) findViewById(R.id.edittextGuess);

buttonSetting =(Button) findViewById(R.id.buttonSetting);
preferences = getSharedPreferences("LIMITS",MODE_PRIVATE);




  buttonSetting.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        Intent intent = new Intent(MainActivity.this,        SecondaryActivity.class);
        startActivity(intent);
    }
});
}

@Override
protected void onStart() {
super.onStart();
final int MinNumber = preferences.getInt("Seekbar Min", 0);
final int MaxNumber = preferences.getInt("Seekbar Max", 0);
textViewChoice.setText("" + MinNumber + "-" + MaxNumber);

editTextNum.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        Random random = new Random();
        int RanNum = random.nextInt(MaxNumber-MinNumber)+MinNumber;
        String StringEditNum= editTextNum.getText().toString();
        if(!StringEditNum.equals("")){
        int EditNum = Integer.parseInt(StringEditNum);
        if (EditNum >RanNum){
            textViewStatus.setText("Enter Higher Number");
        }
        else if(EditNum <RanNum){
            textViewStatus.setText("Enter Lower Numer!");


        }

        else {
            textViewStatus.setText("You won! You Nutz!");
        }
    }else{
          Toast.makeText(MainActivity.this,"Error!",Toast.LENGTH_SHORT).show();
    }
 }
    @Override
    public void afterTextChanged(Editable editable) {

    }
});

}

@Override
protected void onStop() {
super.onStop();
}

@Override
protected void onDestroy() {
super.onDestroy();
}
}

清除Android Studio中的EditText时应用崩溃

6 个答案: