有的大牛只写怎样怎样理解概念，喜欢讲一些概念，有的大牛干脆不写技术，有的大牛只会唯利是图，卖一些组件，我不是大牛，我喜欢帮助别人。

今天我们看看档案管理界面的数据查询与展示，先上一张图，调一下胃口。

这个界面主要的看点有DataGrid数据展示，分组，分页，Convert的使用等。首先我们来看一下界面的代码，这个布局方式采用Grid+StackPanel布局，代码如下。

<controls:ChildWindow.Resources> 
        <StateConvert:ArchiveStateConvert x:Key="ArchiveConvert"></StateConvert:ArchiveStateConvert> 
        <StateConvert:SexConvert x:Key="SexConvert"></StateConvert:SexConvert> 
        <LocalResource:ArchiveManageResource x:Key="LocalResource"></LocalResource:ArchiveManageResource> 
        <Style x:Key="ColumnHeaderStyle" TargetType="sdk:DataGridColumnHeader"> 
            <Setter Property="FontSize" Value="12"></Setter> 
        </Style> 
    </controls:ChildWindow.Resources> 省略部分代码
                <TextBlock Text="{Binding tb_Name,Source={StaticResource LocalResource}}" Margin="10,0,0,0" FontSize="12" Grid.Row="0" Grid.Column="5"/> 
                <sdk:AutoCompleteBox Width="130" FontSize="12" Grid.Row="0" Grid.Column="6" ItemsSource="{Binding PersonList,Mode=OneWay}" SelectedItem="{Binding SelectedPerson,Mode=TwoWay}"/> 
                    <StackPanel Grid.Row="3" Grid.Column="2" Grid.ColumnSpan="3" Margin="0,5,0,0" Orientation="Horizontal" HorizontalAlignment="Center"> 
                    <Button Content="{Binding btn_Search,Source={StaticResource LocalResource}}" Command="{Binding QueryCommands}" FontSize="12" Width="90" Margin="0,0,5,0"/> 
                    <Button Content="{Binding btn_Reset,Source={StaticResource LocalResource}}" FontSize="12" Width="90"/> 
                </StackPanel> 
            </Grid> 
        </Border> 
            <sdk:DataGrid Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2" 
                          IsReadOnly="True" x:Name="dgArchiveList" 
                          ItemsSource="{Binding MyCollectionViewSource.View,Mode=OneWay}" 
                          AutoGenerateColumns="False" 
                          AlternatingRowBackground="Silver" 
                          ColumnHeaderHeight="20" 
                          FrozenColumnCount="3" 
                          CanUserReorderColumns="True" 
                          VerticalScrollBarVisibility="Auto" 
                          HorizontalScrollBarVisibility="Auto"   
                          AreRowGroupHeadersFrozen="False" 
                          SelectionMode="Single" 
                          CanUserSortColumns="False" 
                          LoadingRowGroup="MyDataGrid_LoadingRowGroup"> 
                <sdk:DataGrid.Columns> 
                    <!--<sdk:DataGridTemplateColumn Header="选择"> 
                        <sdk:DataGridTemplateColumn.CellTemplate> 
                            <DataTemplate> 
                                <CheckBox Checked="{Binding IsChecked,Mode=TwoWay}"/> 
                            </DataTemplate> 
                        </sdk:DataGridTemplateColumn.CellTemplate> 
                    </sdk:DataGridTemplateColumn>--> 
                    <sdk:DataGridTextColumn Binding="{Binding ArchiveState,Mode=OneWay,Converter={StaticResource ArchiveConvert}}"> 
                        <sdk:DataGridTextColumn.HeaderStyle> 
                            <Style TargetType="sdk:DataGridColumnHeader"> 
                                <Setter Property="ContentTemplate"> 
                                    <Setter.Value> 
                                        <DataTemplate> 
                                            <TextBlock Text="{Binding Grid_Header_ArchiveState,Source={StaticResource LocalResource}}"/> 
                                        </DataTemplate> 
                                    </Setter.Value> 
                                </Setter> 
                                <Setter Property="FontSize" Value="12"/> 
                            </Style> 
                        </sdk:DataGridTextColumn.HeaderStyle> 
                    </sdk:DataGridTextColumn> 
                    <sdk:DataGridTextColumn HeaderStyle="{StaticResource ColumnHeaderStyle}" Header="档案编号" Binding="{Binding ArchiveNo,Mode=OneWay}" /> 
                    省略部分代码                
            </sdk:DataGrid.Columns> 
            </sdk:DataGrid> 省略部分代码
                <StackPanel Grid.Row="1" Grid.Column="1" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,10,0,0"> 
                <HyperlinkButton x:Name="linkFirst" Foreground="Blue" Tag="First" IsEnabled="{Binding IsLinkFirstEnable,Mode=OneWay}" Click="HyperlinkButton_Click" Content="{Binding link_First,Source={StaticResource LocalResource}}" FontSize="12"/> 
                <HyperlinkButton x:Name="linkPrevious" Foreground="Blue" Tag="Previous"  IsEnabled="{Binding IsLinkPreviousEnable,Mode=OneWay}" Click="HyperlinkButton_Click" Content="{Binding link_Previous,Source={StaticResource LocalResource}}" FontSize="12"/> 
                <HyperlinkButton x:Name="linkNext" Foreground="Blue" Tag="Next" IsEnabled="{Binding IsLinkNextEnable,Mode=OneWay}" Click="HyperlinkButton_Click" Content="{Binding link_Next,Source={StaticResource LocalResource}}" FontSize="12"/> 
                <HyperlinkButton x:Name="linkLast" Foreground="Blue" Tag="Last" IsEnabled="{Binding IsLinkLastEnable,Mode=OneWay}" Click="HyperlinkButton_Click" Content="{Binding link_Last,Source={StaticResource LocalResource}}" FontSize="12"/> 
            </StackPanel> 
</controls:ChildWindow>

查询条件中使用了AutoComplete，<sdk:AutoCompleteBox Width="130" FontSize="12" Grid.Row="0" Grid.Column="6" ItemsSource="{Binding PersonList,Mode=OneWay}" SelectedItem="{Binding SelectedPerson,Mode=TwoWay}"/>。首先其ItemsSource绑定的是一个List<string>,SelectedItem绑定的是选择项，我们看看效果。

当我在姓名文本框中输入“李”的时侯，所有姓李的人都列出来了。当我选择了一个人名以后，SelectedPerson的值将会变为我选择的人名，因为SelectedPerson是个双向绑定。ok我们再往下看，我们发现前台代码的DataGrid列中有这么一行。

<sdk:DataGridTextColumn Binding="{Binding ArchiveState,Mode=OneWay,Converter={StaticResource ArchiveConvert}}"> 
       <sdk:DataGridTextColumn.HeaderStyle> 
            <Style TargetType="sdk:DataGridColumnHeader"> 
                  <Setter Property="ContentTemplate"> 
                      <Setter.Value> 
                         <DataTemplate> 
                             <TextBlock Text="{Binding Grid_Header_ArchiveState,Source={StaticResource LocalResource}}"/> 
                         </DataTemplate> 
                      </Setter.Value> 
                  </Setter> 
                  <Setter Property="FontSize" Value="12"/> 
            </Style> 
       </sdk:DataGridTextColumn.HeaderStyle> 
</sdk:DataGridTextColumn>

这个写法是因为假如我们要给列头国际化，因为DataGrid的DataGridTextColumn的Header是不可以绑定Resource文件的(因为ColumnHeader是DependencyObject类型的，而不是DepenencyProperty)，所以我们只能给它指定Style。这就是这个列和其他列不同的原因，其他列是直接设置Header的。OK，再看这么一段代码

 <sdk:DataGridTextColumn HeaderStyle="{StaticResource ColumnHeaderStyle}" Header="性别" Binding="{Binding Sex,Mode=OneWay,Converter={StaticResource SexConvert}}"/>

我们发现Binding中有个Converter属性，这个是用来转换性别的，假如Sex的值是1，转换为男，假如是0，转换为女。首先需要在页面引用这个实现了IValueConverter 的类，如上代码xmlns:StateConvert="clr-namespace:Client.Common;assembly=Common"先引用命名空间，在引用类<StateConvert:SexConvert x:Key="SexConvert"></StateConvert:SexConvert>，我们看看这个SexConvert 类,如下

namespace Client.Common  
{  
    public class SexConvert : IValueConverter  
    {  
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)  
        {  
            string s = (string)value;  
            switch (s)  
            {  
                case "1":  
                    s = "男";  
                    break;  
                case "0":  
                    s = "女";  
                    break;  
            }  
            return s;  
        }  
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)  
        {  
            string strValue = value.ToString().Equals("男") ? "1" : "0";  
            return strValue;  
        }  
    }  
}

实现Convert和ConvertBack即可。接下来我们要看的是DataGrid的分页和分组，和上一篇文章一样，查询绑定的是Command，所以逻辑都在ViewModel中。我们看看代码

public ICommand QueryCommands  
        {  
            get 
            {  
                QueryCommand queryCommand = new QueryCommand();  
                queryCommand.Query += delegate()  
                {  
                    this.CurrentPage = 1;  
                    var queryRequest = new SearchRequest()  
                    {  
                        ArchiveNo = this.ArchiveNo,  
                        GraduateStartDate = this.StartDate,  
                        GraduateEndDate = this.EndDate,  
                        Name = this.SelectedPerson,  
                        Sex = this.Sex,  
                        BirthDay = this.BirthDay,  
                        IdCard = this.IdCard,  
                        Professional = this.Professional,  
                        GraduateSchool = this.GraduateSchool,  
                        Education = this.Education,  
                        ArchiveState = this.ArchiveState,  
                        PageIndex = -1,  
                        PageSize = this.PageSize  
                    };  
                    GetData(queryRequest);  
                };  
                return queryCommand;  
            }  
        }  
 
        public void GetData(SearchRequest queryRequest)  
        {  
            string requestStr = SeriealizeHelper<SearchRequest>.JsonSerialize<SearchRequest>(queryRequest);  
            ArchiveInfoService.ArchiveInfoServiceClient client = new ArchiveInfoService.ArchiveInfoServiceClient();  
            List<ArchiveInfoEntity> list = new List<ArchiveInfoEntity>();  
            client.GetPersonInfoListCompleted += delegate(object sender, ArchiveInfoService.GetPersonInfoListCompletedEventArgs e)  
            {  
                ArchiveInfoEntity entity;  
                e.Result.PersonInfoList.ForEach(r =>  
                {  
                    entity = new ArchiveInfoEntity();  
                    entity.IsChecked = false;  
                    entity.ArchiveNo = r.no;  
                    entity.ArchiveState = r.state;  
                    entity.BirthDay = r.birth;  
                    entity.Education = r.education_level;  
                    entity.GraduateSchool = r.graduate_school;  
                    entity.GraduateYear = r.graduate_year;  
                    entity.IdCardNo = r.id_card;  
                    entity.IsChecked = false;  
                    entity.Name = r.name;  
                    entity.Professional = r.professional;  
                    entity.Sex = r.sex;  
                    list.Add(entity);  
                });  
                this.RecordCount = e.Result.RecordCount;  
                this.TotalPage = e.Result.RecordCount % PageSize == 0 ? e.Result.RecordCount / PageSize : e.Result.RecordCount / PageSize + 1;  
                this.SetLinkBtnEnable(queryRequest);  
                CollectionViewSource collectionViewSource = new CollectionViewSource();  
                collectionViewSource.Source = list;  
                collectionViewSource.GroupDescriptions.Add(new PropertyGroupDescription("ArchiveState"));  
                this.MyCollectionViewSource = collectionViewSource;  
            };  
            client.GetPersonInfoListAsync(requestStr);  
        }  
 
        private void SetLinkBtnEnable(SearchRequest request)  
        {  
            this.SetLinkEnable(true);  
            if (this.TotalPage <= 1)  
            {  
                this.SetLinkEnable(false);  
            }  
            if (request.PageIndex == this.TotalPage-2)  
            {  
                this.IsLinkNextEnable = false;  
                this.IsLinkLastEnable = false;  
            }  
            if (request.PageIndex == -1 && this.TotalPage > 1)  
            {  
                this.IsLinkFirstEnable = false;  
                this.IsLinkPreviousEnable = false;  
            }  
        }  
 
        private void SetLinkEnable(bool isEnable)  
        {  
            this.IsLinkFirstEnable = isEnable;  
            this.IsLinkLastEnable = isEnable;  
            this.IsLinkNextEnable = isEnable;  
            this.IsLinkPreviousEnable = isEnable;  
        }

从前台代码我们可以看出，分页按钮的isEnabled状态分别绑定ViewModel中的IsLinkFirstEnable ，IsLinkLastEnable，IsLinkNextEnable，IsLinkPreviousEnable。在GetData中有这么一段代码，就是获取到数据源以后，我们对其进行了分组，

this.RecordCount = e.Result.RecordCount;  
this.TotalPage = e.Result.RecordCount % PageSize == 0 ? e.Result.RecordCount / PageSize : e.Result.RecordCount / PageSize + 1;  
this.SetLinkBtnEnable(queryRequest);  
CollectionViewSource collectionViewSource = new CollectionViewSource();  
collectionViewSource.Source = list;  
collectionViewSource.GroupDescriptions.Add(new PropertyGroupDescription("ArchiveState"));  
this.MyCollectionViewSource = collectionViewSource;

我们获取到分页数据以后，根据ArchiveState属性进行分组，然后绑定到界面，注意，DataGrid界面绑定代码ItemsSource="{Binding MyCollectionViewSource.View,Mode=OneWay}"，注意在这里是MyCollectionViewSource.View。接下来是分页，分页是我自己定义的一个分页。我们看看页面cs代码

private void HyperlinkButton_Click(object sender, RoutedEventArgs e)  
{  
     HyperlinkButton hyperLink = sender as HyperlinkButton;  
     var queryRequest = new SearchRequest()  
     {  
           ArchiveNo = archiveModel.ArchiveNo,  
           GraduateStartDate = archiveModel.StartDate,  
           GraduateEndDate = archiveModel.EndDate,  
           Name = archiveModel.SelectedPerson,  
           Sex = archiveModel.Sex,  
           BirthDay = archiveModel.BirthDay,  
           IdCard = archiveModel.IdCard,  
           Professional = archiveModel.Professional,  
           GraduateSchool = archiveModel.GraduateSchool,  
           Education = archiveModel.Education,  
           ArchiveState = archiveModel.ArchiveState,  
           PageSize = archiveModel.PageSize,  
     };  
     switch (hyperLink.Tag.ToString())  
     {  
           case "First":  
               archiveModel.PageIndex = -1;  
               break;  
           case "Next":  
               archiveModel.PageIndex++;  
               break;  
           case "Previous":  
               archiveModel.PageIndex--;  
               break;  
           case "Last":  
               archiveModel.PageIndex = archiveModel.TotalPage-2;  
               break;  
     }  
     archiveModel.CurrentPage = archiveModel.PageIndex + 2;  
     queryRequest.PageIndex = archiveModel.PageIndex;  
     archiveModel.GetData(queryRequest);  
}

在分页的时候调用ViewModel的GetData方法，在ViewModel中动态的设置分页按钮的enabled状态。为了方便大家理解我的意思，我会把ViewModel的cs作为附件供大家下载。ok，我们看看服务端分页代码，如下

public SearchResponse GetPersonInfoList(string searchRequest)  
{  
      SearchRequest searchRequests = SerializeHelper.JsonDeserialize<SearchRequest>(searchRequest);  
      IQueryable<Person_Info> personInfo = misInfoEntities.person_info  
                .Where(p => (string.IsNullOrEmpty(searchRequests.ArchiveNo) ? true : searchRequests.ArchiveNo.Contains(p.no))  
                && (string.IsNullOrEmpty(searchRequests.Name) ? true : p.name == searchRequests.Name)  
                && (string.IsNullOrEmpty(searchRequests.Sex) ? true : p.sex == searchRequests.Sex)  
                && (string.IsNullOrEmpty(searchRequests.IdCard) ? true : p.id_card.Contains(searchRequests.IdCard))  
                && (string.IsNullOrEmpty(searchRequests.Professional) ? true : p.professional == searchRequests.Professional)  
                && (string.IsNullOrEmpty(searchRequests.Education) ? true : p.education_level == searchRequests.Education)  
                && (string.IsNullOrEmpty(searchRequests.ArchiveState) ? true : p.state == searchRequests.ArchiveState)  
                && (!searchRequests.GraduateStartDate.HasValue ? true : p.graduate_year >= searchRequests.GraduateStartDate.Value.Year)  
                && (!searchRequests.GraduateEndDate.HasValue ? true : p.graduate_year <= searchRequests.GraduateEndDate.Value.Year)  
                && (!searchRequests.BirthDay.HasValue ? true : p.birth == searchRequests.BirthDay));  
      IEnumerable<Person_Info> personInfos = personInfo.AsEnumerable().OrderBy(p => p.name)  
                .Skip(searchRequests.PageSize * (searchRequests.PageIndex + 1))  
                .Take(searchRequests.PageSize);  
      foreach (var person in personInfos)  
      {  
          person.education_level = misInfoEntities.codes.SingleOrDefault(c => c.ename == "EDUCATION" && c.data == person.education_level).display_content;  
      }  
      return new SearchResponse() { PersonInfoList = personInfos.ToList(), RecordCount = personInfo.Count() };  
}

在这里因为我的服务端的数据访问层是EF，所以采用的是LINQ to Entities的方式。今天就写到这里，因为篇幅有限，有很多代码没有贴，需要代码的同志可以留言，我可以发给大家，或者加入.net群205217091，我可以共享给大家。