WPF中的数据绑定Data Binding使用小结

完整的数据绑定的语法说明可以在这里查看：

http://www.nbdtech.com/Free/WpfBinding.pdf

MSDN资料：

Data Binding: Part 1 http://msdn.microsoft.com/en-us/library/aa480224.aspx

Data Binding: Part 2 http://msdn.microsoft.com/en-us/library/aa480226.aspx

Data Binding Overview http://msdn.microsoft.com/en-us/library/ms752347.aspx

 

      INotifyPropertyChanged接口   绑定的数据源对象一般都要实现INotifyPropertyChanged接口。

     {Binding}  说明了被绑定控件的属性的内容与该控件的DataContext属性关联，绑定的是其DataContext代表的整个控件的内容。如下：

ContentControl 只是一个纯粹容纳所显示内容的一个空控件，不负责如何具体显示各个内容，借助于DataTemplate可以设置内容的显示细节。

     使用参数Path

（使用父元素的DataContext）使用参数绑定，且在数值变化时更新数据源。（两种写法）

< TextBox Text =" {Binding Path=Name, UpdateSourceTrigger=PropertyChanged} " />
< TextBox.Text >
< Binding Path ="StartPrice" UpdateSourceTrigger ="PropertyChanged" />
TextBox.Text >

     相对资源RelativeSource

RelativeSource={RelativeSource Self}是一个特殊的绑定源，表示指向当前元素自己。自己绑定自己，将ToolTip属性绑定到Validation.Errors中第一个错误项的错误信息(Validation.Errors)[0].ErrorContent。

绑定：相对资源

< Style x:Key ="textStyleTextBox" TargetType =" {x:Type TextBox} " >
< Setter Property ="Foreground" Value ="#333333" />
< Setter Property ="MaxLength" Value ="40" />
< Setter Property ="Width" Value ="392" />
< Style.Triggers >
< Trigger Property ="Validation.HasError" Value ="true" >
< Setter Property ="ToolTip"
Value =" {Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent} " />
Trigger >
Style.Triggers >
Style >

     使用转换器和验证规则

绑定：转换器和验证规则

< TextBox Name ="StartDateEntryForm" Grid.Row ="3" Grid.Column ="1" Style =" {StaticResource textStyleTextBox} " Margin ="8,5,0,5" Validation.ErrorTemplate =" {StaticResource validationTemplate} " >
< TextBox.Text >
< Binding Path ="StartDate" UpdateSourceTrigger ="PropertyChanged" Converter =" {StaticResource dateConverter} " >
< Binding.ValidationRules >
< src:FutureDateRule />
Binding.ValidationRules >
Binding >
TextBox.Text >
TextBox >

//自定义的验证规则须从ValidationRule继承。
class FutureDateRule : ValidationRule
{
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
DateTime date;
try
{
date = DateTime.Parse(value.ToString());
}
catch (FormatException)
{
return new ValidationResult(false, "Value is not a valid date.");
}
if (DateTime.Now.Date > date)
{
return new ValidationResult(false, "Please enter a date in the future.");
}
else
{
return new ValidationResult(true, null);
}
}
}

     使用数据触发器

SpecialFeatures是一个枚举数据类型。

绑定：数据触发器

< DataTrigger Binding =" {Binding Path=SpecialFeatures} " >
< DataTrigger.Value >
< src:SpecialFeatures > Color src:SpecialFeatures >
DataTrigger.Value >
< Setter Property ="BorderBrush" Value ="DodgerBlue" TargetName ="border" />
< Setter Property ="Foreground" Value ="Navy" TargetName ="descriptionTitle" />
< Setter Property ="Foreground" Value ="Navy" TargetName ="currentPriceTitle" />
< Setter Property ="BorderThickness" Value ="3" TargetName ="border" />
< Setter Property ="Padding" Value ="5" TargetName ="border" />
DataTrigger >

    多重绑定

    绑定源是多个源，绑定目标与绑定源是一对多的关系。

多重绑定

< ComboBox.IsEnabled >
< MultiBinding Converter =" {StaticResource specialFeaturesConverter} " >
< Binding Path ="CurrentUser.Rating" Source =" {x:Static Application.Current} " />
< Binding Path ="CurrentUser.MemberSince" Source =" {x:Static Application.Current} " />
MultiBinding >
ComboBox.IsEnabled >
//自定义的转换器须实现IMultiValueConverter接口。
class SpecialFeaturesConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
//数组中的对象数值的索引顺序与XAML文件的多重绑定定义有关。
int rating = (int)values[0];
DateTime date = (DateTime)values[1];

return ((rating >= 10) && (date.Date < (DateTime.Now.Date - new TimeSpan(365, 0, 0, 0))));
}

public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
return new object[2] { Binding.DoNothing, Binding.DoNothing };
}
}

    Master-Detail：主-从应用（使用CollectionViewSource）

主从应用

< CollectionViewSource Source =" {Binding Source={x:Static Application.Current}, Path=AuctionItems} " x:Key ="listingDataView" />
< ListBox Name ="Master" Grid.Row ="2" Grid.ColumnSpan ="3" Margin ="8" ItemsSource =" {Binding Source={StaticResource listingDataView}} " >
ListBox >
< ContentControl Name ="Detail" Grid.Row ="3" Grid.ColumnSpan ="3" Margin ="9,0,0,0" Content =" {Binding Source={StaticResource listingDataView}} " ContentTemplate =" {StaticResource detailsProductListingTemplate} " />

说明：
AuctionItems的定义为：public ObservableCollection AuctionItems  。
在 ListBox 中直接使用 CollectionViewSource 来表示主数据（AuctionItem集合），在 ContentControl 中则同时使用设定 Content 和 ContentControl 两个属性， Content 直接指向CollectionViewSource， ContentControl 则使用先前已经定义的数据模板绑定（数据模板中的数据项则是绑定到AuctionItem类的各个属性）。

     数据分组（使用CollectionViewSource）
分组表头项的数据模板：

   

在ListBox中使用分组：

   
       
   

分组开关：
Group by category
CheckBox的事件处理：
private void AddGrouping(object sender, RoutedEventArgs e)
{
    PropertyGroupDescription pgd = new PropertyGroupDescription();
    pgd.PropertyName = "Category"; //使用属性Category的数值来分组
    listingDataView.GroupDescriptions.Add(pgd);
}
private void RemoveGrouping(object sender, RoutedEventArgs e)
{
    listingDataView.GroupDescriptions.Clear();
}

     排序数据（使用CollectionViewSource） 比分组简单
排序开关：
Sort by category and date
CheckBox的事件处理：
private void AddSorting(object sender, RoutedEventArgs e)
{
    listingDataView.SortDescriptions.Add(new SortDescription("Category", ListSortDirection.Ascending));
    listingDataView.SortDescriptions.Add(new SortDescription("StartDate", ListSortDirection.Descending));
}
private void RemoveSorting(object sender, RoutedEventArgs e)
{
    listingDataView.SortDescriptions.Clear();
}

     过滤数据（使用CollectionViewSource） 跟排序类似
过滤开关：
Show only bargains
CheckBox的事件处理：
private void AddFiltering(object sender, RoutedEventArgs e)
{
    listingDataView.Filter += new FilterEventHandler(ShowOnlyBargainsFilter);
}
private void RemoveFiltering(object sender, RoutedEventArgs e)
{
    listingDataView.Filter -= new FilterEventHandler(ShowOnlyBargainsFilter);
}
private void ShowOnlyBargainsFilter(object sender, FilterEventArgs e)
{
    AuctionItem product = e.Item as AuctionItem;
    if (product != null)
    {
        //设置e.Accepted的值即可
        e.Accepted = product.CurrentPrice < 25;
    }
}

转载于:https://www.cnblogs.com/glowworm/archive/2010/06/19/1760977.html