【Telerik】查询控件的使用

在SilverLight项目中，实现模糊查询，并将值绑定到列表中，使用了Telerik中的<telerik:RadMaskedTextBox>控件。

要先添加命名空间的引用： xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"

并且项目要添加引用：

xaml页面代码：

  <!-- 检索-->
                     <Border>
                         <Grid HorizontalAlignment="Left" Width="150">
                             <Grid.ColumnDefinitions>
                                 <ColumnDefinition Width="Auto"></ColumnDefinition>
                                 <ColumnDefinition></ColumnDefinition>
                             </Grid.ColumnDefinitions>
                             <Image  Grid.Column="0" Source="/MASP;Component/Images/Find.png" Stretch="Uniform" Margin="4"></Image>
                             <telerik:RadMaskedTextBox  x:Name="mask_treat" Grid.Column="1" Margin="3" BorderThickness="0"
 EmptyContent="输入关键字进行检索" MaskType="None" VerticalAlignment="Center" ValueChanged="mask_treat_ValueChanged"></telerik:RadMaskedTextBox>
                         </Grid>
                     </Border>

xaml.cs代码：文本内容发生改变事件ValueChanged

  private void mask_treat_ValueChanged(object sender, Telerik.Windows.RadRoutedEventArgs e)
         {
             try
             {
                 string value = mask_treat.MaskedText == null ? "" : mask_treat.MaskedText.ToString().Trim();

                 IList<GridViewDataColumn> ViewDataColumns = new List<GridViewDataColumn>();
                 ViewDataColumns.Add(Rgv_treatlist.Columns[] as GridViewDataColumn);
                 ViewDataColumns.Add(Rgv_treatlist.Columns[] as GridViewDataColumn);
                 ViewDataColumns.Add(Rgv_treatlist.Columns[] as GridViewDataColumn);
                 CustomFilterDescriptor FilterDescriptor = new CustomFilterDescriptor(ViewDataColumns);
                 FilterDescriptor.FilterValue = value;
                 Rgv_treatlist.FilterDescriptors.Clear();
                 Rgv_treatlist.FilterDescriptors.Add(FilterDescriptor);
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message);
             }
         }

CustomFilterDescriptor类代码：

 using Telerik.Windows.Controls;
 using Telerik.Windows.Data;  

 public class CustomFilterDescriptor : FilterDescriptorBase
     {
         private readonly CompositeFilterDescriptor compositeFilterDesriptor;
         private static readonly ConstantExpression TrueExpression = System.Linq.Expressions.Expression.Constant(true);
         private string filterValue;

         public CustomFilterDescriptor(IEnumerable<Telerik.Windows.Controls.GridViewColumn> columns)
         {
             this.compositeFilterDesriptor = new CompositeFilterDescriptor();
             this.compositeFilterDesriptor.LogicalOperator = FilterCompositionLogicalOperator.Or;

             foreach (GridViewDataColumn column in columns)
             {
                 this.compositeFilterDesriptor.FilterDescriptors.Add(this.CreateFilterForColumn(column));
             }
         }

         public string FilterValue
         {
             get
             {
                 return this.filterValue;
             }
             set
             {
                 if (this.filterValue != value)
                 {
                     this.filterValue = value;
                     this.UpdateCompositeFilterValues();
                     this.OnPropertyChanged("FilterValue");
                 }
             }
         }

         protected override System.Linq.Expressions.Expression CreateFilterExpression(ParameterExpression parameterExpression)
         {
             if (string.IsNullOrEmpty(this.FilterValue))
             {
                 return TrueExpression;
             }
             try
             {
                 return this.compositeFilterDesriptor.CreateFilterExpression(parameterExpression);
             }
             catch
             {
             }

             return TrueExpression;
         }

         private IFilterDescriptor CreateFilterForColumn(GridViewDataColumn column)
         {
             FilterOperator filterOperator = GetFilterOperatorForType(column.DataType);
             FilterDescriptor descriptor = new FilterDescriptor(column.UniqueName, filterOperator, this.filterValue);
             descriptor.MemberType = column.DataType;

             return descriptor;
         }

         private static FilterOperator GetFilterOperatorForType(Type dataType)
         {
             return dataType == typeof(string) ? FilterOperator.Contains : FilterOperator.IsEqualTo;
         }

         private void UpdateCompositeFilterValues()
         {
             foreach (FilterDescriptor descriptor in this.compositeFilterDesriptor.FilterDescriptors)
             {
                 object convertedValue = DefaultValue(descriptor.MemberType);

                 try
                 {
                     convertedValue = Convert.ChangeType(this.FilterValue, descriptor.MemberType, null);
                 }
                 catch
                 {
                 }

                 if (!descriptor.MemberType.IsAssignableFrom(typeof(DateTime)))
                 {
                     descriptor.Value = convertedValue; ;

                 }
             }
         }

         private static object DefaultValue(Type type)
         {
             if (type.IsValueType)
             {
                 return Activator.CreateInstance(type);
             }

             return null;
         }
     }

记录完成。