Android中Dialog的使用
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>