通过 IDictionary对Silverlight DataGrid 进行动态数据绑定

最新推荐文章于 2025-04-05 23:58:01 发布

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最新推荐文章于 2025-04-05 23:58:01 发布

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分类专栏： .Net相关 silverLight 文章标签： datagrid silverlight dictionary object class ui

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通过 IDictionary对Silverlight DataGrid 进行动态数据绑定

要对DataGrid进行数据绑定，通常我们需要定义具体类，而后建立类的范式集合。如下所示：

public class BasicInfo
    {
         public string id { set ; get ; }
         public string name { set ; get ; }
         public string tel { set ; get ; }
    }

    private void LoadDataByClass()
        {
            var result = new ObservableCollection < BasicInfo > ();
            result.Add( new BasicInfo { id = " 1001 " , name = " Ivan " , tel = " 135462512 " });
            result.Add( new BasicInfo { id = " 1002 " , name = " Ivan2 " , tel = " 135462512 " });
            result.Add( new BasicInfo { id = " 1003 " , name = " Ivan3 " , tel = " 135462512 " });

            dgshow.ItemsSource = result;
        }

      也就说说，如果要在DataGrid中show集合数据，就需要有具体类的存在【匿名类在绑定的时候会出现运行期异常】。这在很多情况下是可行的.
      但是有时候，某个集合只需要show一次而已，而我们又不得不给建立具体类以使得其信息能够在DataGrid中显示。也就是说在要显示的集合的列不确定时，建立具体类实在是有点“浪费”。
      这种情况下，我们可以建立“自己”的集合类【这时候免不了要用到Indexer】，利用Dictionary来动态建立集合列，从而实现数据的动态添加和显示：

public class Row
    {
        Dictionary < string , object > dictionary = new Dictionary < string , object > ();

         public object this [ string index]
        {
             get
            {
                 return dictionary[index];
            }
             set
            {
                dictionary[index] = value;
            }
        }
    }

        private void LoadDataByDictionary()
        {
            var result = new ObservableCollection < Row > ();

            Row row = new Row();
            row[ " id " ] = " Dic1001 " ;
            row[ " name " ] = " Ivan " ;
            row[ " tel " ] = " 123456 " ;
            result.Add(row);

            row = new Row();
            row[ " id " ] = " Dic1002 " ;
            row[ " name " ] = " Ivan2 " ;
            row[ " tel " ] = " 12345622 " ;
            result.Add(row);

            dgshowDic.ItemsSource = result;

        }

这样产生的集合，在DataGrid绑定时，绑定的为Row.所以在UI显示之前，要对数据集合进行转换,使得DataGrid中显示需要显示的列数据：

   public class RowIndexConverter : IValueConverter
    {
         public object Convert( object value, Type targetType, object parameter, CultureInfo culture)
        {
            Row row = value as Row;
             string index = parameter as string ;
             return row[index];
        }

         public object ConvertBack( object value, Type targetType, object parameter, CultureInfo culture)
        {
             throw new NotImplementedException();
        }
    }

附带Xaml的定义代码：

< UserControl xmlns:data ="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"   x:Class ="CodeProjectDemo.Page"
    xmlns ="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x ="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:local ="clr-namespace:CodeProjectDemo"
   Loaded ="UserControl_Loaded" >
     < UserControl.Resources >
         < local:RowIndexConverter x:Key ="RowIndexConverter" ></ local:RowIndexConverter >
         < local:DateConverter x:Key ="DateConverter" ></ local:DateConverter >
     </ UserControl.Resources >
     < Canvas >
         < Button x:Name ="btnDic" Height ="50" Width ="150" Content ="LoadDataBy Dictionary" FontSize ="12"   Click ="btnDic_Click" ></ Button >
         < Button x:Name ="btnCls" Canvas.Left ="200"   Height ="50" Width ="150" Content ="LoadDataBy Class" FontSize ="12"   Click ="btnCls_Click" ></ Button >

         < data:DataGrid x:Name ="dgshow" Canvas.Top ="70" Canvas.Left ="400"   Height ="auto" Width ="150" AutoGenerateColumns ="True" ></ data:DataGrid >
         < data:DataGrid Name ="dgshowDic" Canvas.Top ="70" AutoGenerateColumns ="False" Height ="auto" IsReadOnly ="False" >
             < data:DataGrid.Columns >
                 < data:DataGridTextColumn Header ="id" Binding =" {Binding Converter={StaticResource RowIndexConverter}, ConverterParameter=id} " />
                 < data:DataGridTextColumn Header ="name" Binding =" {Binding Converter={StaticResource RowIndexConverter}, ConverterParameter=name} " />
                 < data:DataGridTextColumn Header ="tel" Binding =" {Binding Converter={StaticResource RowIndexConverter}, ConverterParameter=tel} " />
             </ data:DataGrid.Columns >
         </ data:DataGrid >
         < ListBox x:Name ="MyListBox" Canvas.Top ="300" Canvas.Left ="10" >
             < ListBox.ItemTemplate >
                 < DataTemplate >
                     < StackPanel Orientation ="Horizontal" >
                         < TextBlock Text =" {Binding Time1, Converter={StaticResource DateConverter}} " Margin ="5" Foreground ="Red" ></ TextBlock >
                         < TextBlock Text =" {Binding Time2} " Margin ="5" ></ TextBlock >
                     </ StackPanel >
                 </ DataTemplate >
             </ ListBox.ItemTemplate >
         </ ListBox >
     </ Canvas >
</ UserControl >

ps:注意到 IValueConverter 的应用，可以参考msdn.
建立转换类后，其将作为一个资源存在，故而在xaml中要对此资源进行说明【见上述xaml】。
下面是对此接口的一个简单应用：在ListBox中显示时间前对其进行格式化。

Code
public class DateConverter : IValueConverter
    {
         public object Convert( object value, Type targetType, object parameter, CultureInfo culture)
        {
            DateTime date = (DateTime)value;
             return date.ToShortDateString();
        }

         public object ConvertBack( object value, Type targetType, object parameter, CultureInfo culture)
        {
             throw new NotImplementedException();
        }
    }
     public class MyTime
    {
         public DateTime Time1 { get ; set ; }
         public DateTime Time2 { get ; set ; }
    }