本次實驗中主要是學習如何使用RadioGroup,CheckBox,RadioButton和Toast這幾個控件,其中RadioButton是單選按鈕,多個RadioButton放在一個RadioGroup控件中,也就是說每次只能有1個RadioButton被選中。而CheckBox是多選按鈕,Toatst是android中帶的一個用於顯示提示小窗口消息的控件,其提示的內容過一會兒會自動消失。
RadioGroup和CheckBox控件設置監聽器都是用的setOnCheckedChangeListener函數,其輸入參數是一個函數,且函數內部要實現1個內部類。RadioGroup監聽器的輸入參數用的是RadioGroup.OnCheckedChangeListener(),而CheckBox監聽器的輸入參數用的是函數CompoundButton.OnCheckedChangeListener().
開發環境:android4.1
實驗效果如下(采用的是線性布局):
效果圖1:
效果圖2:
上面3個為一組RadioGroup,每選中其中一個RadioButton,則會有相應的提示。且只能選中其中的一個。
下面的4都為CheckBox,可以選中其中的多個。每個CheckBox被選中或者取消選中都有相應的文字提示小窗口。
代碼如下:
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 { //定義各控件的變量 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); //獲得對應的控件 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); //設置who_group的監聽器,其實是一句代碼,其參數是一個帶有重構函數的對象 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,"中國", Toast.LENGTH_SHORT).show(); } else if(checkedId == america.getId()){ Toast.makeText(MainActivity.this, "美國", Toast.LENGTH_SHORT).show(); } else if(checkedId == others.getId()){ Toast.makeText(MainActivity.this, "其它國家", Toast.LENGTH_SHORT).show(); } } }); //下面為4個checkbox多選按鈕分別建立監聽器 less.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // TODO Auto-generated method stub if(isChecked) { Toast.makeText(MainActivity.this, "30個以下", Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(MainActivity.this, "不是30個以下", Toast.LENGTH_SHORT).show(); } } }); //下面為4個checkbox多選按鈕分別建立監聽器 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(); } } }); //下面為4個checkbox多選按鈕分別建立監聽器 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(); } } }); //下面為4個checkbox多選按鈕分別建立監聽器 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:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:id="@+id/who" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/who" /> <RadioGroup android:id="@+id/who_group" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" > <RadioButton android:id="@+id/china" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="@string/china" /> <RadioButton android:id="@+id/america" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/america" /> <RadioButton android:id="@+id/others" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/others" /> </RadioGroup> <TextView android:id="@+id/how" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/how" /> <CheckBox android:id="@+id/less" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/less" /> <CheckBox android:id="@+id/thirty" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/thirty" /> <CheckBox android:id="@+id/forty" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/forty" /> <CheckBox android:id="@+id/fifty" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/fifty" /> </LinearLayout>
實驗總結:通過本次實驗對RadioGroup,CheckBox,RadioButton和Toast這4個控件的簡單使用有了個初步的了解。