本次实验中主要是学习如何使用RadioGroup,CheckBox,RadioButton和Toast这几个控件,其中RadioButton是单选按钮,多个RadioButton放在一个RadioGroup控件中,也就是说每次只能有1个RadioButton被选中。而CheckBox是多选按钮,Toatst是android中带的一个用于显示提示小窗口消息的控件,其提示的内容过一会儿会自动消失。
RadioGroup和CheckBox控件设置监听器都是用的setOnCheckedChangeListener函数,其输入参数是一个函数,且函数内部要实现1个内部类。RadioGroup监听器的输入参数用的是RadioGroup.OnCheckedChangeListener(),而CheckBox监听器的输入参数用的是函数CompoundButton.OnCheckedChangeListener().
开发环境:android4.1
实验效果如下(采用的是线性布局):
效果图1:
效果图2:
上面3个为一组RadioGroup,每选中其中一个RadioButton,则会有相应的提示。且只能选中其中的一个。
下面的4都为CheckBox,可以选中其中的多个。每个CheckBox被选中或者取消选中都有相应的文字提示小窗口。
代码如下:
MainActivity.java:
package com.example.control1;import android.app.Activity;import android.os.Bundle;import android.widget.CheckBox;import android.widget.CompoundButton;import android.widget.CompoundButton.OnCheckedChangeListener;import android.widget.RadioButton;import android.widget.RadioGroup;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity { //定义各控件的变量 private TextView who = null; private TextView how = null; private RadioGroup who_group = null; private RadioButton china = null; private RadioButton america = null; private RadioButton others = null; private CheckBox less = null; private CheckBox thirty = null; private CheckBox forty = null; private CheckBox fifty = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //获得对应的控件 who = (TextView)findViewById(R.id.who); how = (TextView)findViewById(R.id.how); who_group = (RadioGroup)findViewById(R.id.who_group); china = (RadioButton)findViewById(R.id.china); america = (RadioButton)findViewById(R.id.america); others = (RadioButton)findViewById(R.id.others); less = (CheckBox)findViewById(R.id.less); thirty = (CheckBox)findViewById(R.id.thirty); forty = (CheckBox)findViewById(R.id.forty); fifty = (CheckBox)findViewById(R.id.fifty); //设置who_group的监听器,其实是一句代码,其参数是一个带有重构函数的对象 who_group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { public void onCheckedChanged(RadioGroup group, int checkedId) { // TODO Auto-generated method stub if(checkedId == china.getId()){ Toast.makeText(MainActivity.this,"中国", Toast.LENGTH_SHORT).show(); } else if(checkedId == america.getId()){ Toast.makeText(MainActivity.this, "美国", Toast.LENGTH_SHORT).show(); } else if(checkedId == others.getId()){ Toast.makeText(MainActivity.this, "其它国家", Toast.LENGTH_SHORT).show(); } } }); //下面为4个checkbox多选按钮分别建立监听器 less.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // TODO Auto-generated method stub if(isChecked) { Toast.makeText(MainActivity.this, "30个以下", Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(MainActivity.this, "不是30个以下", Toast.LENGTH_SHORT).show(); } } }); //下面为4个checkbox多选按钮分别建立监听器 thirty.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // TODO Auto-generated method stub if(isChecked) { Toast.makeText(MainActivity.this, "30~39", Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(MainActivity.this, "不是30~39", Toast.LENGTH_SHORT).show(); } } }); //下面为4个checkbox多选按钮分别建立监听器 forty.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // TODO Auto-generated method stub if(isChecked) { Toast.makeText(MainActivity.this, "40~49", Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(MainActivity.this, "不是40~49", Toast.LENGTH_SHORT).show(); } } }); //下面为4个checkbox多选按钮分别建立监听器 fifty.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // TODO Auto-generated method stub if(isChecked) { Toast.makeText(MainActivity.this, "50以上", Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(MainActivity.this, "不是50以上", Toast.LENGTH_SHORT).show(); } } }); }}
activity_main.xml:
实验总结:通过本次实验对RadioGroup,CheckBox,RadioButton和Toast这4个控件的简单使用有了个初步的了解。