java - void 是此变量的无效类型

Question

我收到此错误：

void 是变量 onRadioButtonClicked 的无效类型

但是开发者网站说 void 是必须的！那么问题出在哪里？xml的编码是正确的。问题一定出在这里：

package com.example.kernel.version;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;

public class MainPage extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Intent intent=getIntent();
        setContentView(R.layout.activity_main_page);       

        public void onRadioButtonClicked(View view) {
            // Is the button now checked?
            boolean checked = ((RadioButton) view).isChecked();

            // Check which radio button was clicked
            switch(view.getId()) {
                case R.id.radio_pirates:
                    if (checked)
                        // Pirates are the best
                    break;
                case R.id.radio_ninjas:
                    if (checked)
                        // Ninjas rule
                    break;
            }

        }

Answer 1

你onRadioButtonClicked包含在你的onCreate方法中——使它们成为单独的方法。在以下之后添加右大括号}：

setContentView(R.layout.activity_main_page); 

Answer 2

像这样做：

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;

public class MainPage extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Intent intent=getIntent();
        setContentView(R.layout.activity_main_page);       




    }

    public void onRadioButtonClicked(View view) {
        // Is the button now checked?
        boolean checked = ((RadioButton) view).isChecked();

        // Check which radio button was clicked
        switch(view.getId()) {
            case R.id.radio_pirates:
                if (checked)
                    // Pirates are the best
                break;
            case R.id.radio_ninjas:
                if (checked)
                    // Ninjas rule
                break;
        }

    }
}