Dialog是android开发过程中最常用到的组件之一，它包括以下几种类型：

　　警告对话框：Alertialog

　　进度对话框：ProgressDialog

　　日期选择对话框：DatePickerDialog

　　时间选择对话框：TimePickerDialog

　　自定义对话框：从Dialog继承

　　Dialog的创建方式有两种：

　　一是直接new一个Dialog对象，然后调用Dialog对象的show和dismiss方法来控制对话框的显示和隐藏。

　　二是在Activity的onCreateDialog(int id)方法中创建Dialog对象并返回，然后调用Activty的showDialog(int id)和dismissDialog(int id)来显示和隐藏对话框。

　　区别在于通过第二种方式创建的对话框会继承Activity的属性，比如获得Activity的menu事件等。

　　使用AlertDialog可以创建普通对话框、带列表的对话框以及带单选按钮和多选按钮的对话框。

　　普通对话框

　　效果如下：

　　代码：

//创建builder
                AlertDialog.Builder builder = new AlertDialog.Builder(DialogSampleActivity.this);
                builder.setTitle("普通对话框")    //标题
                    .setIcon(R.drawable.ic_launcher)    //icon
                    .setCancelable(false)    //不响应back按钮
                    .setMessage("这是一个普通对话框")    //对话框显示内容
                  //设置按钮
                    .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(DialogSampleActivity.this, "点击了确定按钮", Toast.LENGTH_SHORT).show();
                        }
                    })
                    .setNeutralButton("中立", new DialogInterface.OnClickListener() {                        
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(DialogSampleActivity.this, "点击了中立按钮", Toast.LENGTH_SHORT).show();
                        }
                    })
                    .setNegativeButton("取消", new DialogInterface.OnClickListener() {                    
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(DialogSampleActivity.this, "点击了取消按钮", Toast.LENGTH_SHORT).show();
                        }
                    });
                //创建Dialog对象
                AlertDialog dlg = builder.create();
                return dlg;

带列表的对话框

　　效果图：

　　代码：

　final CharSequence[] items = { "Item1", "Item2", "Item3" };
            // 创建builder
            AlertDialog.Builder builder = new AlertDialog.Builder(
                    DialogSampleActivity.this);
            builder.setTitle("列表对话框") // 标题
                    .setIcon(R.drawable.ic_launcher) // icon
                    .setCancelable(false) // 不响应back按钮
                    .setItems(items, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(DialogSampleActivity.this,
                                    "选择了" + items[which], Toast.LENGTH_SHORT)
                                    .show();
                        }
                    });
            // 创建Dialog对象
            AlertDialog dlg = builder.create();
            return dlg;

　　带单选按钮的列表对话框

　　只需将setItems替换为：

.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(DialogSampleActivity.this,
                                    "选择了" + items[which], Toast.LENGTH_SHORT)
                                    .show();
                        }
                    });

　　这里多了一个参数-1，代表默认选中第几项，-1表示默认不选中

　　带复选框的列表对话框

　　只需将setItems替换为：

.setMultiChoiceItems(items, checked, new DialogInterface.OnMultiChoiceClickListener() {        
                        @Override
                        public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                            Toast.makeText(DialogSampleActivity.this,
                                    "选择了" + items[which], Toast.LENGTH_SHORT)
                                    .show();
                        }
                    });

参数checked伟boolean数组，表示默认哪些复选框是被选中的。

　　另外，如果你想要获取list中哪些项是被选中的，你需要：

//获得ListView
ListView list = dlg.getListView();
//判断第i项是否被选中，为真表示被选中，为假表示没有选中
list.getCheckedItemPositions().get(i)

日期选择对话框

　　效果图：

　　代码：

Calendar calendar = Calendar.getInstance();
            DatePickerDialog.OnDateSetListener dateListener =   
                new DatePickerDialog.OnDateSetListener() {  
                    @Override  
                    public void onDateSet(DatePicker datePicker,   
                            int year, int month, int dayOfMonth) {  
                        Toast.makeText(DialogSampleActivity.this,
                                year + "年" + (month+1) + "月" + dayOfMonth + "日", Toast.LENGTH_SHORT)
                                .show();  
                    }
                };  
            DatePickerDialog dlg = new DatePickerDialog(
                    DialogSampleActivity.this,
                    dateListener,
                    calendar.get(Calendar.YEAR),
                    calendar.get(Calendar.MONTH),
                    calendar.get(Calendar.DAY_OF_MONTH));
            return dlg;

　　时间选择对话框

　　效果图：

　　代码：

　Calendar calendar = Calendar.getInstance();
            TimePickerDialog.OnTimeSetListener timeListener =   
                new TimePickerDialog.OnTimeSetListener() {

                    @Override
                    public void onTimeSet(TimePicker timePicker, int hourOfDay, int minute) {
                        Toast.makeText(DialogSampleActivity.this,
                                hourOfDay + ":" + minute, Toast.LENGTH_SHORT).show();  
                    }  
                   
                };  
            TimePickerDialog dlg = new TimePickerDialog(
                    DialogSampleActivity.this,
                    timeListener,
                    calendar.get(Calendar.HOUR_OF_DAY),
                    calendar.get(Calendar.MINUTE),
                    true);
            return dlg;

　　自定义对话框

　　效果图：

　　步骤：

　　1、创建对话框的布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content">
      <!-- 标题栏 -->
      <LinearLayout
          android:id="@+id/dlg_priority_titlebar"
          android:orientation="horizontal"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_alignParentTop="true">
          <ImageView
            android:src="@drawable/star_gray"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="5dip"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="选择任务优先级"
            android:layout_gravity="center_vertical"/>
      </LinearLayout>
      <!-- 任务优先级 -->
      <ListView
          android:id="@+id/dlg_priority_lvw"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/dlg_priority_titlebar"
          android:background="@drawable/layout_home_bg">
      </ListView>     
</RelativeLayout>

2、因为该布局中使用了自定义的ListView，所以再为ListView创建布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="horizontal"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    >    <ImageView          android:id="@+id/list_priority_img"          android:layout_width="wrap_content"          android:layout_height="wrap_content"          android:layout_gravity="center_vertical"          android:layout_margin="5dip"                  />    <TextView         android:id="@+id/list_priority_value"         android:layout_width="wrap_content"         android:layout_height="wrap_content"        android:layout_gravity="center_vertical"         android:textSize="28dip"         android:textColor="@drawable/black"/></LinearLayout>
 
3、创建自定义Dialog类PriorityDlg继承自Dialog

public class PriorityDlg extends Dialog {
    
    private Context context;
    private ListView dlg_priority_lvw = null;

    public PriorityDlg(Context context) {
        super(context);
        this.context = context;
        // TODO Auto-generated constructor stub
    }
    
    public PriorityDlg(Context context, int theme) {
        super(context, theme);
        this.context = context;
    }
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
   　　　//设置对话框使用的布局文件
        this.setContentView(R.layout.dlg_priority);

        dlg_priority_lvw = (ListView) findViewById(R.id.dlg_priority_lvw);

        // 设置ListView的数据源
        SimpleAdapter adapter = new SimpleAdapter(context, getPriorityList(),
                R.layout.lvw_priority, new String[] { "list_priority_img",
                        "list_priority_value" }, new int[] {
                        R.id.list_priority_img, R.id.list_priority_value });
        dlg_priority_lvw.setAdapter(adapter);

        // 为ListView设置监听器
        dlg_priority_lvw
                .setOnItemClickListener(new AdapterView.OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> arg0, View arg1,
                            int arg2, long arg3) {

                    }
                });
    }

    /**
     * 得到ListView数据源
     * 
     * @return
     */
    private List<HashMap<String, Object>> getPriorityList() {
        List<HashMap<String, Object>> priorityList = new ArrayList<HashMap<String, Object>>();
        HashMap<String, Object> map1 = new HashMap<String, Object>();
        map1.put("list_priority_img", R.drawable.priority_not_important);
        map1.put("list_priority_value", context.getResources().getString(
                R.string.dlg_priority_not_important));
        priorityList.add(map1);
        HashMap<String, Object> map2 = new HashMap<String, Object>();
        map2.put("list_priority_img", R.drawable.priority_general);
        map2.put("list_priority_value", context.getResources().getString(
                R.string.dlg_priority_general));
        priorityList.add(map2);
        HashMap<String, Object> map3 = new HashMap<String, Object>();
        map3.put("list_priority_img", R.drawable.priority_important);
        map3.put("list_priority_value", context.getResources().getString(
                R.string.dlg_priority_important));
        priorityList.add(map3);
        HashMap<String, Object> map4 = new HashMap<String, Object>();
        map4.put("list_priority_img", R.drawable.priority_very_important);
        map4.put("list_priority_value", context.getResources().getString(
                R.string.dlg_priority_very_important));
        priorityList.add(map4);

        return priorityList;
    }

}

4、创建自定义对话框

PriorityDlg dlg = new PriorityDlg(SimpleTaskActivity.this, R.style.dlg_priority);
return dlg;

这里的R.style.dlg_priority设置了对话框使用的样式文件，只是让对话框去掉标题栏，当然你也可以通过代码来完成这种效果：

<?xml version="1.0" encoding="utf-8"?><resources>    <!-- 对话框样式 -->    <style name="dlg_priority" parent="@android:Theme.Dialog">        <item name="android:windowNoTitle">true</item>    </style></resources>
 
到这里自定义对话框的创建就结束了，想要什么样子的对话框完全凭你自己的想像。