Question

当我试图运行它所说的代码时，应用程序已经停止了。请帮我编写代码。下面是我想要解决方案的代码。

package gaurav.android;

import java.util.*;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class EventActivity extends Activity {
    /** Called when the activity is first created. */
    View colorregion;
    int[] colorchoices = {Color.BLACK , Color.BLUE, Color.CYAN};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        colorregion = findViewById(R.id.color_region);
        Button clbutton = (Button)findViewById(R.id.color_button);
        clbutton.setOnClickListener((OnClickListener) new ColorRandomizer());
    }
    private void regioncolor(int color)
    {
        colorregion.setBackgroundColor(color);
    }
    private class ColorRandomizer implements onClickListener
    {
        public void onClick(View v)
        {
            Random r= new Random();
            int index= r.nextInt(colorchoices.length);
            regioncolor(colorchoices[index]);
        }
    }
}

Answer 1

更改您的代码

private class ColorRandomizer implements onClickListener
    {
        public void onClick(View v)
        {
            Random r= new Random();
            int index= r.nextInt(colorchoices.length);
            regioncolor(colorchoices[index]);
        }
    }

到此

private class ColorRandomizer implements OnClickListener {
        public void onClick(View v) {
            Random r = new Random();
            int index = r.nextInt(colorchoices.length);
            regioncolor(colorchoices[index]);
        }
    }

它不是onClickListener OnClickListener

Answer 2

    package com.test;

    import java.util.Random;

    import android.app.Activity;
    import android.graphics.Color;
    import android.os.Bundle;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;

    public class EventActivity extends Activity 
    {
     /** Called when the activity is first created. */
    View colorregion;
    int[] colorchoices = {Color.BLACK , Color.BLUE, Color.CYAN};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        colorregion = findViewById(R.id.color_region);
        Button clbutton = (Button)findViewById(R.id.color_button);
        clbutton.setOnClickListener(new ColorRandomizer());
    }
    private void regioncolor(int color)
    {
        colorregion.setBackgroundColor(color);
    }
    private class ColorRandomizer implements OnClickListener
    {
        public void onClick(View v)
        {
            Random r= new Random();
            int index= r.nextInt(colorchoices.length);
            regioncolor(colorchoices[index]);
        }
    }

}

应用程序强制关闭运行。

2 个答案: