SilverLight学习笔记--实际应用(一)(4):手把手建立一个Silverlight应用程序之同步数据校验1...

  现在我们的程序有了添加和删除以及修改功能，下面我们看一看如何让程序具备数据校验功能。我们将用两种方式实现数据的校验，一种是在客户端进行同步校验。另一种是在服务器端进行异步校验。
  本篇我们先实现如何在客户端进行同步校验。基本原理是：利用数据的双向绑定和INotifyPropertyChanged 接口以及控件的NotifyOnValidationError与ValidatesOnExceptions两个属性设置来配合实现客户端同步校验。
 现在继续修改完善我们的程序。
 1、修改用户界面如下:

Code
<UserControl xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"  x:Class="SLApplicationDataTest.Page"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="300">
    <StackPanel Height="500" Background="White">
        <StackPanel Orientation="Horizontal">
            <Button x:Name="addButton" Content="Add" Margin="10"/>
            <Button x:Name="deleteButton" Content="Delete" Margin="10"/>
        </StackPanel>
        <data:DataGrid x:Name="dgPeople" AutoGenerateColumns="False" >
            <data:DataGrid.Columns>
                <data:DataGridTextColumn     Header="Name"  Binding="{Binding Name}"  />
                <data:DataGridTextColumn     Header="Sex"  Binding="{Binding Sex}"  />
                <data:DataGridTemplateColumn Header="Age">
                    <data:DataGridTemplateColumn.CellTemplate >
                        <DataTemplate>
                            <TextBlock  Text="{Binding Age}"  ToolTipService.ToolTip="请输入0至200之间的整数！"></TextBlock>
                        </DataTemplate>
                    </data:DataGridTemplateColumn.CellTemplate>
                    <data:DataGridTemplateColumn.CellEditingTemplate>
                        <DataTemplate>
                            <TextBox Text="{Binding Age , Mode=TwoWay, NotifyOnValidationError=True,  ValidatesOnExceptions=True}" BindingValidationError="TextBox_BindingValidationError" 
                                     ToolTipService.ToolTip="请输入0至200之间的整数！"></TextBox>
                        </DataTemplate>
                    </data:DataGridTemplateColumn.CellEditingTemplate>
                </data:DataGridTemplateColumn>
                <data:DataGridTextColumn     Header="Address"  Binding="{Binding Address}"  />
            </data:DataGrid.Columns>
        </data:DataGrid>
    </StackPanel>
</UserControl>

      在此界面中，我们不再是简单地进行绑定数据和显示数据，而是对DataGrid控件进行了改造，尤其是运用了模板来定义我们的Age字段。注意Age字段的CellEditingTemplate模板，它的两个属性:NotifyOnValidationError，ValidatesOnExceptions都必须设置为true,这样才会在绑定出错时报错，而对错误事件的处理则字义在BindingValidationError事件中。
2、修改Person类
在此类中加入绑定数据的校验工作。具体代码如下:

Code
 public int Age
        {
            get { return _age; }
            set
            {
                if (value == _age) return;

                 //如果输入的不是整数，则抛出异常
                try
                {
                    Convert.ToInt32(value);
                }
                catch(Exception ex)
                {
                    throw new Exception(ex.ToString());
                }
                 
                //如果输入的整数不在合理范围同，则也抛出异常

                if (value < 0 || value > 200)
                {
                    throw new Exception("Age must be between 0 and 200");
                }


                _age = value;
                OnPropertyChanged("Age");
            }
        }

Person类全部代码如下:

Code
using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.ComponentModel; //因为要用到INotifyPropertyChanged接口


namespace SLApplicationDataTest
{
    public class Person : INotifyPropertyChanged
    {
        private string _name;
        private string _sex;
        private int _age;
        private string _address;

        #region Constructors
        public Person() { }

        public Person(string NameStr, string SexStr, int AgeInt, string AddressStr)
        {
            this._name = NameStr;
            this._sex = SexStr;
            this._age = AgeInt;
            this._address = AddressStr;
        }
        #endregion


        #region Properties

        public string Name
        {
            get { return _name; }
            set
            {
                if (value == _name) return;
                _name = value;
                OnPropertyChanged("Name");
            }
        }

        public string Sex
        {
            get { return _sex; }
            set
            {
                if (value == _sex) return;
                _sex = value;
                OnPropertyChanged("Sex");
            }
        }

        public int Age
        {
            get { return _age; }
            set
            {
                if (value == _age) return;

                 //如果输入的不是整数，则抛出异常
                try
                {
                    Convert.ToInt32(value);
                }
                catch(Exception ex)
                {
                    throw new Exception(ex.ToString());
                }
                 
                //如果输入的整数不在合理范围同，则也抛出异常

                if (value < 0 || value > 200)
                {
                    throw new Exception("Age must be between 0 and 200");
                }


                _age = value;
                OnPropertyChanged("Age");
            }
        }

        public string Address
        {
            get { return _address; }
            set
            {
                if (value == _address) return;
                _address = value;
                OnPropertyChanged("Address");
            }
        }
        #endregion

        #region INotifyPropertyChanged 接口实现
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string name)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(name));
        }
        #endregion

    }
}

  3、完成校验错误处理程序

Code
   #region 校验错误处理程序
        private void TextBox_BindingValidationError(object sender, ValidationErrorEventArgs e)
        {
            
            if (e.Action == ValidationErrorEventAction.Added)
            {
               //((Control)e.OriginalSource).Background = new SolidColorBrush(Colors.Red);
               //((Control)e.OriginalSource).SetValue(ToolTipService.ToolTipProperty, e.Error.Exception.Message);
               //((Control)e.OriginalSource).Focus();
               this.Dispatcher.BeginInvoke(() => HtmlPage.Window.Alert(e.Error.Exception.Message));

              
            }
            else if (e.Action == ValidationErrorEventAction.Removed)
            {
                //((Control)e.OriginalSource).Background = new SolidColorBrush(Colors.White);
                //((Control)e.OriginalSource).SetValue(ToolTipService.ToolTipProperty, null);
            }

        }
        #endregion

  Page.xaml.cs全部代码如下:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Browser; //因为要使用HtmlPage.Window.Alert(message));

namespace SLApplicationDataTest
{
    public partial class Page : UserControl
    {
        People mypeople;
        public Page()
        {
            InitializeComponent();

            this.addButton.Click += new RoutedEventHandler(addButton_Click);
            this.deleteButton.Click += new RoutedEventHandler(deleteButton_Click);
            this.dgPeople.KeyDown += new KeyEventHandler(peopleDataGrid_KeyDown);



            Loaded += new RoutedEventHandler(Page_Loaded);
        }

        private void Page_Loaded(object sender, RoutedEventArgs e)
        {
            取得数据源数据并绑定到DataGrid控件上#region 取得数据源数据并绑定到DataGrid控件上
            mypeople = People.GetTestData();
            this.dgPeople.ItemsSource = mypeople;
            #endregion

        }

        通过按钮添加新记录行#region 通过按钮添加新记录行
        void addButton_Click(object sender, RoutedEventArgs e)
        {
            mypeople.Add(new Person());
        }
        #endregion

        通过按钮删除记录#region 通过按钮删除记录
        void deleteButton_Click(object sender, RoutedEventArgs e)
        {
            DeletePerson();
        }
        #endregion

        删除记录子程序#region 删除记录子程序
        private void DeletePerson()
        {
            if (null == this.dgPeople.SelectedItem)
            {
                return;
            }
            Person person = this.dgPeople.SelectedItem as Person;
            if (null == person)
            {
                return;
            }
            mypeople.Remove(person);
        }
        #endregion

        处理键盘响应事件#region 处理键盘响应事件
        void peopleDataGrid_KeyDown(object sender, KeyEventArgs e)
        {
            如果是Insert键，则做插入新行操作#region 如果是Insert键，则做插入新行操作
            if (Key.Insert == e.Key)
            {
                mypeople.Add(new Person());
            }
            #endregion

            如果是Delete键，则做删除操作#region 如果是Delete键，则做删除操作
            if (Key.Delete == e.Key)
            {
                DeletePerson();
            }
            #endregion
        }
        #endregion


        校验错误处理程序#region 校验错误处理程序
        private void TextBox_BindingValidationError(object sender, ValidationErrorEventArgs e)
        {
            
            if (e.Action == ValidationErrorEventAction.Added)
            {
                //如果校验出错，则抛出错误提示窗口
               /**/////((Control)e.OriginalSource).Background = new SolidColorBrush(Colors.Red);
               ////((Control)e.OriginalSource).SetValue(ToolTipService.ToolTipProperty, e.Error.Exception.Message);
               ////((Control)e.OriginalSource).Focus();
               this.Dispatcher.BeginInvoke(() => HtmlPage.Window.Alert(e.Error.Exception.Message));

              
            }
            else if (e.Action == ValidationErrorEventAction.Removed)
            {
                //如果校验通过，则做如下处理
                /**/////((Control)e.OriginalSource).Background = new SolidColorBrush(Colors.White);
                ////((Control)e.OriginalSource).SetValue(ToolTipService.ToolTipProperty, null);
            }

        }
        #endregion

    }
}

运行效果如下：