WPF之DataTemplate
DataTemplate顧名思義,就是數據模板,用來指定數據的表現形式。這對於ItemsControl類的控件尤其有用,可以改變列表項的外觀,更具有表現能力。
例如
<Grid>
<Grid.Resources>
<src:Customers x:Key="customers"/>
</Grid.Resources>
<ListBox ItemsSource="{StaticResource customers}" Width="350" Margin="0,5,0,10">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Padding="5,0,5,0"
Text="{Binding FirstName}" />
<TextBlock Text="{Binding LastName}" />
<TextBlock Text=", " />
<TextBlock Text="{Binding Address}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
<Grid> <Grid.Resources> <src:Customers x:Key="customers"/> </Grid.Resources> <ListBox ItemsSource="{StaticResource customers}" Width="350" Margin="0,5,0,10"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Padding="5,0,5,0" Text="{Binding FirstName}" /> <TextBlock Text="{Binding LastName}" /> <TextBlock Text=", " /> <TextBlock Text="{Binding Address}" /> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> </Grid>
上例中通過指定ListBox.ItemTemplate屬性來定義子項的顯示格式,如果不是列表項,可以通過控件的ContentTemplate屬性來指定應用哪個數據模板。
使用起來比較簡單,大概分為三步:
1.如果有些屬性不是可以直接使用,需要轉換的,寫轉換器,實現IValueConverter接口
2.定義好轉換器之后,需要實例化,指定給需要的綁定
3.定義模板,也就是需要的顯示格式
4.應用模板,把定義好的模板指定到目標控件的ContentTemplate或者ItemTemplate
看一個完整的例子
1.用來封裝的實體類和轉換器
class Car
{
public string Automaker { get; set; }
public string Name { get; set; }
public string Year { get; set; }
public string TopSpeed { get; set; }
}
//廠商名稱轉化為Logo圖片
public class AutomakerToLogoPathConverter:IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
string uriStr = string.Format(@"images/{0}.jpg",value.ToString());
return new BitmapImage(new Uri(uriStr, UriKind.Relative));
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
//汽車名稱轉化為圖像
public class NameToPhotoPathConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
string uriStr = string.Format(@"images/{0}.jpg", value.ToString());
return new BitmapImage(new Uri(uriStr, UriKind.Relative));
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
class Car { public string Automaker { get; set; } public string Name { get; set; } public string Year { get; set; } public string TopSpeed { get; set; } } //廠商名稱轉化為Logo圖片 public class AutomakerToLogoPathConverter:IValueConverter { public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { string uriStr = string.Format(@"images/{0}.jpg",value.ToString()); return new BitmapImage(new Uri(uriStr, UriKind.Relative)); } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { throw new NotImplementedException(); } } //汽車名稱轉化為圖像 public class NameToPhotoPathConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { string uriStr = string.Format(@"images/{0}.jpg", value.ToString()); return new BitmapImage(new Uri(uriStr, UriKind.Relative)); } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { throw new NotImplementedException(); } }
2.模板及窗體
<Window x:Class="TempaletPractise.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:TempaletPractise"
Title="汽車展覽" Height="350" Width="623">
<Window.Resources>
<!--Converter-->
<local:AutomakerToLogoPathConverter x:Key="a2l"></local:AutomakerToLogoPathConverter>
<local:NameToPhotoPathConverter x:Key="n2p"></local:NameToPhotoPathConverter>
<!--Data Template for Detail View-->
<DataTemplate x:Key="carDetailViewTemplate">
<Border BorderBrush="Black" BorderThickness="1" CornerRadius="6">
<StackPanel Margin="5">
<Image Width="400" Height="250" Source="{Binding Name, Converter={StaticResource n2p}}"></Image>
<StackPanel Orientation="Horizontal" Margin="5,0">
<TextBlock Text="Name:" FontWeight="Bold" FontSize="20"></TextBlock>
<TextBlock Text="{Binding Name}" FontSize="20" Margin="5,0"></TextBlock>
</StackPanel>
<StackPanel Orientation="Horizontal" Margin="5,0">
<TextBlock Text="Automaker" FontWeight="Bold"></TextBlock>
<TextBlock Text="{Binding Automaker}" Margin="5,0"></TextBlock>
<TextBlock Text="Year" FontWeight="Bold"></TextBlock>
<TextBlock Text="{Binding Year}" Margin="5,0"></TextBlock>
<TextBlock Text="Top Speed" FontWeight="Bold"></TextBlock>
<TextBlock Text="{Binding TopSpeed}" Margin="5,0"></TextBlock>
</StackPanel>
</StackPanel>
</Border>
</DataTemplate>
<!--DataTemplate for Item View-->
<DataTemplate x:Key="carListItemViewTemplate">
<Grid Margin="2">
<StackPanel Orientation="Horizontal">
<Image Source="{Binding Automaker,Converter={StaticResource a2l}}"
Grid.RowSpan="3" Width="64" Height="64"></Image>
<StackPanel Margin="5,0">
<TextBlock Text="{Binding Name}" FontSize="16" FontWeight="Bold"></TextBlock>
<TextBlock Text="{Binding Year}" FontSize="14"></TextBlock>
</StackPanel>
</StackPanel>
</Grid>
</DataTemplate>
</Window.Resources>
<!--窗體的內容-->
<StackPanel Orientation="Horizontal" Margin="5">
<UserControl ContentTemplate="{StaticResource carDetailViewTemplate}"
Content="{Binding SelectedItem, ElementName=listBoxCars}"></UserControl>
<ListBox x:Name="listBoxCars" Width="180" Margin="5,0" ItemTemplate="{StaticResource carListItemViewTemplate}"></ListBox>
</StackPanel>
</Window>
3.指定數據源
private void InitialCarList()
{
List<Car> cars = new List<Car>()
{
new Car(){ Automaker="CADILLAC",Name="CADILLAC1",Year="1990",TopSpeed="340"},
new Car(){ Automaker="Ferrari",Name="Ferrari1",Year="1991",TopSpeed="350"},
new Car(){ Automaker="LAMBORGHINI",Name="LAMBORGHINI1",Year="1992",TopSpeed="360"},
new Car(){ Automaker="PORSCHE",Name="PORSCHE1",Year="1993",TopSpeed="370"}
};
this.listBoxCars.ItemsSource = cars;
}
參考 MSDN 《深入淺出WPF》第11章
ps.今天看到園子編輯推薦的一則新聞,Silverlight開始邊緣化,從官方就開始不推了,不知道WPF的命運會怎樣,在微軟的大船上,只能跟着起伏,不過今天能從ASP.NET轉WPF,明天也能從WPF轉其他技術,我們從來就不怕這個,畢竟我們學過,想過,用過,他幫助過我們,每種技術都代表了一種思想,技術可以沒落,思想卻沉淀下來了。