Silverlight:telerik RadControls中RadGridView的一个Bug及解决办法_综合

当RadGridView中嵌套RadComboBox，且RadGridView的高度不够出现滚动条时，上下拉动滚动条后，RadComboBox中的选中值将丢失!

　　如下图：

　　滚动条未拖动前

　　滚动条上下拖动后(注意下图的高亮部分)

　　重现该Bug的测试代码：

　　Model层

　　TextValueObject.cs

namespace RadControlsBug.Model

{

public class TextValueObject

{

public string Text { set ; get ; }

public string Value { set ; get ; }

}

　　SexType.cs

namespace RadControlsBug.Model

{

public class SexType

{

/// <summary>

/// 男

/// </summary>

public static string Male = "男" ;

/// <summary>

/// 女

/// </summary>

public static string FeMale = "女" ;

}

　　SexTypeCollection.cs

using System.Collections.Generic;

namespace RadControlsBug.Model

{

public static class SexTypeCollection

{

private static List<TextValueObject> _items = new List<TextValueObject>();

public static List<TextValueObject> Items

{

get { return _items; }

set { _items = value; }

}

static SexTypeCollection()

{

_items.Add( new TextValueObject() { Text = "男" , Value = SexType.Male });

_items.Add( new TextValueObject() { Text = "女" , Value = SexType.FeMale });

}

　　Person.cs

using System.Collections.Generic;

namespace RadControlsBug.Model

{

public class Person

{

public string Name { set ; get ; }

public string Sex { set ; get ; }

private List<TextValueObject> _sexItems = SexTypeCollection.Items;

public List<TextValueObject> SexItems { get { return _sexItems; } }

}

　　Company.cs

using System.Collections.ObjectModel;

namespace RadControlsBug.Model

{

public class Company

{

private ObservableCollection<Person> _employees = new ObservableCollection<Person>();

public ObservableCollection<Person> Employees

{

get { return _employees; }

set { _employees = value; }

}

public Company()

{

this ._employees.Add( new Person() { Name = "张三" , Sex = SexType.Male });

this ._employees.Add( new Person() { Name = "李四" , Sex = SexType.FeMale });

this ._employees.Add( new Person() { Name = "王五" , Sex = SexType.Male });

this ._employees.Add( new Person() { Name = "赵六" , Sex = SexType.FeMale });

this ._employees.Add( new Person() { Name = "孙七" , Sex = SexType.Male });

this ._employees.Add( new Person() { Name = "杨九" , Sex = SexType.FeMale });

this ._employees.Add( new Person() { Name = "胡十" , Sex = SexType.Male });

}

　　UI层：

　　MainPage.Xaml:

< UserControl x:Class = "RadControlsBug.MainPage"

xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:d = "http://schemas.microsoft.com/expression/blend/2008"

xmlns:mc = "http://schemas.openxmlformats.org/markup-compatibility/2006"

xmlns:telerik = "http://schemas.telerik.com/2008/xaml/presentation"

mc:Ignorable = "d"

d:DesignHeight = "300" d:DesignWidth = "400" >

< Grid x:Name = "LayoutRoot" Background = "White" >

< StackPanel VerticalAlignment = "Center" HorizontalAlignment = "Center" >

< telerik:RadGridView ShowGroupPanel = "False" RowIndicatorVisibility = "Collapsed" CanUserFreezeColumns = "False" AutoGenerateColumns = "False" ItemsSource = "{Binding Employees,Mode=TwoWay}" Width = "300" Height = "120" Name = "gridView1" >

< telerik:RadGridView.Columns >

< telerik:GridViewColumn Header = "姓名" Width = "80" >

< telerik:GridViewColumn.CellTemplate >

< DataTemplate >

< telerik:RadMaskedTextBox Value = "{Binding Name,Mode=TwoWay}" MaskType = "None" ></ telerik:RadMaskedTextBox >

</ DataTemplate >

</ telerik:GridViewColumn.CellTemplate >

</ telerik:GridViewColumn >

< telerik:GridViewColumn Header = "性别" Width = "80" >

< telerik:GridViewColumn.CellTemplate >

< DataTemplate >

< telerik:RadComboBox ItemsSource = "{Binding SexItems,Mode=TwoWay}" SelectedValue = "{Binding Sex,Mode=TwoWay}" SelectedValuePath = "Value" DisplayMemberPath = "Text" />

</ DataTemplate >

</ telerik:GridViewColumn.CellTemplate >

</ telerik:GridViewColumn >

</ telerik:RadGridView.Columns >

</ telerik:RadGridView >

</ StackPanel >

</ Grid >

</ UserControl >

　　MainPage.Xaml.cs：

using System.Windows;

using System.Windows.Controls;

using RadControlsBug.Model;

namespace RadControlsBug

{

public partial class MainPage : UserControl

{

public MainPage()

{

InitializeComponent();

this .Loaded += new RoutedEventHandler(Page_Loaded);

}

void Page_Loaded( object sender, RoutedEventArgs e)

{

Company _viewModel = new Company();

this .DataContext = _viewModel;

}

　　该问题曾经困扰我长达2周之久，在Telerik的论坛上提问也未得到回复。

　　曾经反复尝试，发现解决方法居然极其简单：

　　<telerik:RadComboBox ItemsSource="{Binding SexItems,Mode=TwoWay}" SelectedValue="{Binding Sex,Mode=TwoWay}" SelectedValuePath="Value" DisplayMemberPath="Text"/>

　　改成：

　　<telerik:RadComboBox SelectedValue="{Binding Sex,Mode=TwoWay}" SelectedValuePath="Value" DisplayMemberPath="Text" ItemsSource="{Binding SexItems,Mode=TwoWay}"/>

　　后，问题奇迹般的解决了!

　　分享于此，希望有助于遇到同样问题的朋友。(个人分析：有可能telerik的开发人员在解析XAML时，判断逻辑依赖于属性出现的顺序导致--胡猜的，我也没去看它的源码)

　　最后谈一下我个人对于Telerik RadControls For Silverlight这套控件的感受，用这套控件做项目开发已经有近3个月的时间，总体感觉还不错，能大幅提高团队的开发效率，官方有详细文档和示例，上手非常容易，而且客观来讲，BUG也比较少(用了3个月，基本上才发现这一个比较诡异的BUG)，此外，如果是正版用户，官方还提供源码，并有一年的免费升级期限，每季度官方均会对整套控件做一次升级(主要是修复之前的BUG，以及增加一些新功能)。从成本上考虑，一套控件的售价9k RMB左右(无Licence数量限制，而且能拿到源码任意修改)，国内用户可在慧都控件网上直接购买，对于公司来讲这个成本其实并不高(相比公司招人自己实现这些控件的功能而言，9k多其实可以忽略不计了)，如果您的公司打算致力于企业级应用的RIA开发，建议使用。