Windows Phone 之 SearchTask

　　SearchTask是Windows Phone 眾多任務中一個非常重要的任務，主要執行搜尋任務，在其內部是調用Bing搜尋引擎的相關服務，SearchTask簡單便於使用，下面是SearchTask的類圖：

　　SearchQuery：用於設定查詢搜尋索引鍵

　　Show:調用搜尋服務，顯示搜尋結果

　　在開發Windows Phone Application的時候，如果需要搜尋服務，即可使用SearchTask。下面舉例說明，採用MVVM模式。

XMAL:

<phone:PhoneApplicationPage
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" xmlns:ec="clr-namespace:Microsoft.Expression.Interactivity.Core;assembly=Microsoft.Expression.Interactions" 
    x:Class="SearchTask.MainPage"
xmlns:viewModel="clr-namespace:SearchTask.ViewModel"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.Resources>
            <viewModel:MainPageView x:Key="ViewModel"/>
        </Grid.Resources>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="My First Application" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="Search Page" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" DataContext="{StaticResource ViewModel}" Grid.Row="1" Margin="12,0,12,0">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition />
            </Grid.RowDefinitions>
            <TextBox x:Name="SearchBox" Text="{Binding SearchQuery, Mode=TwoWay}"/>
            <Button x:Name="SearchBut" Content="Search" HorizontalAlignment="Left" VerticalAlignment="Top" Height="81" Margin="4,8,0,0" Grid.Row="1" Width="196" Background="#00C07777">
<i:Interaction.Triggers>
                    <i:EventTrigger EventName="Click">
                        <ec:CallMethodAction MethodName="Search" TargetObject="{Binding}"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>
            </Button>
        </Grid>
    </Grid>
</phone:PhoneApplicationPage>

ViewModel:

public class MainPageView : INotifyPropertyChanged
    {
public event PropertyChangedEventHandler PropertyChanged;

public void OnPropertyChanged(PropertyChangedEventArgs e)
        {
if (PropertyChanged != null)
            {
                PropertyChanged(this, e);
            }
        }

private string searchQuery;

public string SearchQuery
        {
get
            {
return searchQuery;
            }
set
            {
                searchQuery = value;
                PropertyChanged(this, new PropertyChangedEventArgs("SearchQuery"));
            }
        }

public void Search()
        {
            Microsoft.Phone.Tasks.SearchTask task = new Microsoft.Phone.Tasks.SearchTask();
            task.SearchQuery = SearchQuery;
            task.Show();
        }
    }

運行應用程式：

在文字框中輸入：windows phone:

單擊Search:

以上就是SearchTask的使用示範。原始碼：http://files.cnblogs.com/PerfectSoft/SearchTask.zip