小编Nam*_*ora的帖子

我收到此错误:

void是变量onRadioButtonClicked的无效类型

但是开发者网站说虚空是必须的!那问题出在哪里？xml的编码是正确的..问题必须在这里:

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 …

可能重复:
语法问题IF ELSE(Java)

我正在尝试制作一个计算器,如果在编辑框中没有输入任何值,则显示一条消息.但它的FC!我很长一段时间都在制作应用程序,所以我很困惑.

private OnClickListener startListener = new OnClickListener() {
    public void onClick(View v) {               
        double a=0;
        double b=0;
        double c=0;
        EditText edit;
        EditText edit2;
        TextView edit3;
        String lname="";
        edit=(EditText)findViewById(R.id.edit);
        edit2=(EditText)findViewById(R.id.edit2);
        edit3=(TextView)findViewById(R.id.edit3); // everything defined above


        String editstr= edit.getText().toString(); // real work starts
        if(editstr.contentEquals(lname))
            edit3.setText("Enter value");
        else

        a=Double.parseDouble(edit.getText().toString()); // else add the stuff
        b=Double.parseDouble(edit2.getText().toString());
        c=a+b;
        edit3.setText(Double.toString(c));

    } };