Android平台下对话框主要有普通对话框、选项对话框、单选多选对话框、进度对话框、日期对话框、时间对话框等。
在程序中通过开发回调方法onCreateDialog来完成对话框的创建，该方法需要传入代表对话框id参数。如果要显示对话框，则调用showDialog方法传入对话框的id来显示指定对话框。
当对话框第一次被显示时，会调用onCreateDialog方法来创建对话框实例，之后将不再重复创建该实例。每次对话框在被显示之前都会调用onPrepareDialog方法，如不重写该方法，每次显示的对话框都将是最初创建的那个。
关闭对话框可用dismiss方法实现。但如果需要让对话框在关闭之后彻底被清除，要调用removeDialog方法并传入dialog的id来彻底释放对话框。
onDismissListener方法可在关闭对话框时执行一些特定工作。
例子如下：
界面上放置四个按钮：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/tv01" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> <Button android:id="@+id/bt01" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="普通对话框" /> <Button android:id="@+id/bt02" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="列表对话框" /> <Button android:id="@+id/bt03" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="单选按钮对话框" /> <Button android:id="@+id/bt04" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="复选按钮对话框" /> <Button android:id="@+id/bt05" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="日期对话框" /> <Button android:id="@+id/bt06" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="时间对话框" /> <Button android:id="@+id/bt07" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="进度条对话框" /> <DigitalClock android:text="DigitalClock" android:textSize="20dip" android:gravity="center" android:id="@+id/dclock01" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <AnalogClock android:text="AnalogClock" android:textSize="20dip" android:gravity="center" android:id="@+id/aclock01" android:layout_width="fill_parent" android:layout_height="wrap_content" /></LinearLayout>
为每个按钮绑定OnClikListener，其中用showDialog（id）方法显示对话框：
bt01.setOnClickListener(new Button.OnClickListener(){
@Override
public void onClick(View v) { // TODO Auto-generated method stub showDialog(COMMON_DIALOG); }});
覆写onCreateDialog方法：
@Override
protected Dialog onCreateDialog(int id) { // TODO Auto-generated method stub Dialog dialog = null; switch (id) { case COMMON_DIALOG: Builder b1 = new AlertDialog.Builder(this); b1.setIcon(R.drawable.img01); b1.setTitle("普通对话框标题"); b1.setMessage("普通对话框内容"); b1.setPositiveButton("确定", new OnClickListener() {@Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub tv.setText("您选择了普通对话框"); } }); dialog = b1.create(); break;
case LIST_DIALOG:
Builder b2 = new AlertDialog.Builder(this); b2.setIcon(R.drawable.img01); b2.setTitle("列表对话框标题"); b2.setItems(R.array.msa, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub tv.setText("您选择了："+getResources().getStringArray(R.array.msa)[which]); } }); dialog = b2.create(); break;/*其中R.array.msa在res/values下array.xml中：
<?xml version="1.0" encoding="utf-8"?><resources> <string-array name="msa"> <item>游泳</item> <item>篮球</item> <item>足球</item> </string-array></resources>
*/
case LIST_DIALOG_SINGLE: Builder b3 = new AlertDialog.Builder(this); b3.setIcon(R.drawable.img01); b3.setTitle("单选按钮对话框标题"); b3.setSingleChoiceItems(R.array.msa, 0,new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub tv.setText("您选择了："+getResources().getStringArray(R.array.msa)[which]); } }); b3.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub } }); dialog = b3.create(); break; case LIST_DIALOG_MULTIPLE:
Builder b4 = new AlertDialog.Builder(this);
b4.setIcon(R.drawable.img01); b4.setTitle("复选按钮对话框标题"); b4.setMultiChoiceItems(R.array.msa, mulFlags,new DialogInterface.OnMultiChoiceClickListener() { @Override public void onClick(DialogInterface dialog, int which, boolean isChecked) { // TODO Auto-generated method stub mulFlags[which]=isChecked; String result="您选择了："; for(int i=0;i<mulFlags.length;i++){ if(mulFlags[i]){ result+=items[i]+"、"; } } tv.setText(result.substring(0, result.length()-1)); } }); b4.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub } }); dialog = b4.create(); break;case DATE_DIALOG:
c=Calendar.getInstance(); dialog=new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener() { @Override public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { // TODO Auto-generated method stub tv.setText("您选择了"+year+"年"+monthOfYear+"月"+dayOfMonth+"日"); } }, c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DAY_OF_MONTH)); case TIME_DIALOG: c=Calendar.getInstance(); dialog=new TimePickerDialog(this, new TimePickerDialog.OnTimeSetListener() {@Override
public void onTimeSet(TimePicker view, int hourOfDay, int minute) { // TODO Auto-generated method stub tv.setText("您选择了"+hourOfDay+"时"+minute+"分"); } }, c.get(Calendar.HOUR_OF_DAY), c.get(Calendar.MINUTE),false);case PROGRESS_DIALOG:
pd = new ProgressDialog(this); pd.setMax(100); pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); pd.setTitle("安装进度"); pd.setCancelable(false); dialog=pd; break; default: break; } return dialog;}
显示进度进度条需要时刻更新进度条进度，因此需要覆写onPrepareDialpg方法：
@Override
protected void onPrepareDialog(int id, Dialog dialog) { // TODO Auto-generated method stub super.onPrepareDialog(id, dialog); switch (id) { case PROGRESS_DIALOG: pd.incrementProgressBy(-pd.getProgress()); new Thread() {//该线程负责进度对话框的进度，并发送消息至主Activity的handler对象进行更新。 public void run() { while (true) { myHandler.sendEmptyMessage(INCREASE); if (pd.getProgress() >= 100) { break; } try { Thread.sleep(40); } catch (Exception e) { e.printStackTrace(); } } } }.start(); } }
主函数中myhandler：
myHandler = new Handler() {
@Override public void handleMessage(Message msg) { // TODO Auto-generated method stub
switch (msg.what) { case INCREASE: pd.incrementProgressBy(1); if (pd.getProgress() >= 100) { pd.dismiss(); } break; } super.handleMessage(msg); }
};