Android中的无效int错误

Question

我正在尝试创建 Android 应用程序，并认为用于桌面游戏的骰子工具会是一个不错的项目。但是，我在第 40 行不断收到无效的 int 错误，我对自己实际上做错了什么感到非常困惑。

如果有人能以此为我指明正确的方向，我将不胜感激:)

package com.example.isaac.dicetool;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.ToggleButton;

import java.util.Random;

public class MainActivity extends ActionBarActivity {

    EditText et1,et2;
    TextView Result;
    Button button;
    ToggleButton toggle;

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

        et1=(EditText) findViewById(R.id.editText);
        et2=(EditText) findViewById(R.id.editText2);
        Result=(TextView) findViewById(R.id.textView3);
        button=(Button) findViewById(R.id.button1);
        toggle=(ToggleButton) findViewById(R.id.toggleButton);



        button.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View arg0){
            int min = 1;
            int max = 6;
            int rolls = Integer.parseInt(et1.getText().toString());
            int win = Integer.parseInt(et2.getText().toString());
            Random r = new Random();
            int sucess = 0;
            int explode = 0;
            boolean exp =((ToggleButton)arg0).isChecked();

                for(int i=0;i<rolls;i++){
                    int roll = r.nextInt(max-min+1)+min;
                if(roll<win){
                        sucess++;
                    }
                if(exp==true){
                    if(roll==6){
                        rolls++;
                        explode++;
                    }
                }
                }
                Result.setText("Number of successes: " + sucess + "n/Number of explosions: " + explode);
           }
                                  }

        );


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Number of Dice(D6)"
    android:id="@+id/textView"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="number"
    android:ems="10"
    android:id="@+id/editText"
    android:layout_below="@+id/textView"
    android:layout_centerHorizontal="true" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Number for Success"
    android:id="@+id/textView2"
    android:layout_below="@+id/editText"
    android:layout_centerHorizontal="true" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="number"
    android:ems="10"
    android:id="@+id/editText2"
    android:layout_below="@+id/textView2"
    android:layout_centerHorizontal="true"
    android:numeric="integer" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="ROLL!"
    android:id="@+id/button1"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />


<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:id="@+id/textView3"
    android:layout_alignRight="@+id/textView2"
    android:layout_alignEnd="@+id/textView2"
    android:layout_alignLeft="@+id/textView"
    android:layout_alignStart="@+id/textView"
    android:layout_alignParentBottom="true"
    android:layout_below="@+id/button1" />

<ToggleButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="New ToggleButton"
    android:id="@+id/toggleButton"
    android:layout_below="@+id/editText2"
    android:layout_centerHorizontal="true"
    android:textOff="Normal"
    android:textOn="Exploding" />

05-20 13:04:15.830    1866-1866/com.example.isaac.dicetool E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.isaac.dicetool, PID: 1866
java.lang.NumberFormatException: Invalid int: ""
        at java.lang.Integer.invalidInt(Integer.java:137)
        at java.lang.Integer.parseInt(Integer.java:358)
        at java.lang.Integer.parseInt(Integer.java:331)
        at com.example.isaac.dicetool.MainActivity$1.onClick(MainActivity.java:40)
        at android.view.View.performClick(View.java:4438)
        at android.view.View$PerformClick.run(View.java:18422)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5017)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
        at dalvik.system.NativeStart.main(Native Method)

Answer 1

问题是您正试图将空字符串“”值转换为integer！

   int rolls = Integer.parseInt(et1.getText().toString());

如果您的EditText edt1 没有价值，您将在此处获得NumberFormatException。

与下一行代码相同：

  int win = Integer.parseInt(et2.getText().toString());

您可以通过以下方式进行验证：

et1Val = et1.getText().toString();
if (et1Val.matches("")) {
    et1Val = "0";
}
int rolls = Integer.parseInt(et1Val);