using System;
using System.ComponentModel;
namespace *.ViewModels
{public class ProgressIndicatorViewModel : INotifyPropertyChanged{private Boolean isVisible;private String text;private Boolean isIndeterminate;private Double value;/// <summary>/// 获取或设置 是否显示ProgressIndicator。/// </summary>public Boolean IsVisible{get{return isVisible;}set{if (isVisible != value){isVisible = value;NotifyPropertyChanged("IsVisible");}}}/// <summary>/// 获取或设置 显示的文字。/// </summary>public String Text{get{return text;}set{if (text != value){text = value;NotifyPropertyChanged("Text");}}}/// <summary>/// 获取或设置 进度指示器是不确定的还是确定的。/// </summary>public Boolean IsIndeterminate{get{return isIndeterminate;}set{if (isIndeterminate != value){isIndeterminate = value;NotifyPropertyChanged("IsIndeterminate");}}}/// <summary>/// 获取或设置 进度（0-1）。/// </summary>public Double Value{get{return value;}set{if (this.value != value){this.value = value;NotifyPropertyChanged("Value");}}}public ProgressIndicatorViewModel(){isVisible = false;text = String.Empty;isIndeterminate = false;value = 0;}public event PropertyChangedEventHandler PropertyChanged;private void NotifyPropertyChanged(String propertyName){if (null != PropertyChanged)PropertyChanged(this, new PropertyChangedEventArgs(propertyName));}}
}

<phone:PhoneApplicationPageshell:SystemTray.Opacity="0"shell:SystemTray.IsVisible="{Binding IsVisible}"><shell:SystemTray.ProgressIndicator><shell:ProgressIndicator IsVisible="{Binding IsVisible}"Text="{Binding Text}"IsIndeterminate="{Binding IsIndeterminate}"Value="{Binding Value}"/></shell:SystemTray.ProgressIndicator><Grid></Grid></phone:PhoneApplicationPage>