综合应用WPF/WCF/WF/LINQ之二十四：使用UserControl技术编写一个翻页控件

UserControl实现起来比较简单。之所以说简单，是因为它没有多少思维的转换，大体做过.NET 2.0版的控件的人，把代码Copy过来，按照WPF的要求做一些改动即可。如果您要求快速开发，UserControl是一个不错的选择。
　　UserControl的实现步骤如下：
　　1、创建一个WPF User Control Library类型的项目。
　　2、将自动创建的UserControl1.xaml删除，重新添加一个名为Pager.xaml的User Control (WPF)项目。
　　3、将Pager.xaml的代码更改如下：
　　其中，Grid.RowDefinitions和Grid.ColumnDefinitions这部分用于定义行和列，也就类似与HTML中的表格。之后，设定控件的Grid.Row和Grid.Column属性，即可定位这个控件。而具体的控件的绘制，则非常类似与在ASPX页面中绘制控件。
　　值得注意的是：UserControl可直接在控件上捆绑事件，并在后台的xxx.xaml.cs中编写代码。而CustomControl则不建议这么处理，虽然ResourceDictionary文件也可以加上x:Class，之后即可在后台的xxx.xaml.cs中编写代码，但由于CustomControl的主体类和后台的xxx.xaml.cs类这两个实例之间的通讯存在问题，所以我们不建议这样做。想进一步了解的朋友，请参阅综合应用WPF/WCF/WF/LINQ之二十三：采用用DataTemplate的方式实现CheckListBox的CustomControl。

    1  < UserControl x : Class ="Eallies.OA.UI.Controls.Common.Pager"

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

    3    xmlns : x ="http://schemas.microsoft.com/winfx/2006/xaml" Loaded ="UserControl_Loaded">

    4      < Grid >

    5          < Grid.RowDefinitions >

    6              < RowDefinition />

    7          </ Grid.RowDefinitions >

    8          < Grid.ColumnDefinitions >

    9              < ColumnDefinition Width ="Auto" />

   10              < ColumnDefinition Width ="Auto" />

   11              < ColumnDefinition Width ="Auto" />

   12              < ColumnDefinition Width ="Auto" />

   13              < ColumnDefinition Width ="Auto" />

   14              < ColumnDefinition Width ="Auto" />

   15              < ColumnDefinition Width ="Auto" />

   16              < ColumnDefinition Width ="Auto" />

   17              < ColumnDefinition Width ="Auto" />

   18              < ColumnDefinition Width ="22" />

   19              < ColumnDefinition Width ="Auto" />

   20          </ Grid.ColumnDefinitions >

   21          < Label Name ="lblFirst" Content ="&lt;&lt;" Grid.Column ="0" MouseLeftButtonUp ="lblFirst_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   22          < Label Name ="lblPrevious" Content ="&lt;" Grid.Column ="1" MouseLeftButtonUp ="lblPrevious_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   23          < Label Name ="lblPage1" Content ="1" Grid.Column ="2" MouseLeftButtonUp ="lblPage1_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   24          < Label Name ="lblPage2" Content ="2" Grid.Column ="3" MouseLeftButtonUp ="lblPage2_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   25          < Label Name ="lblPage3" Content ="3" Grid.Column ="4" VerticalAlignment ="Center" HorizontalAlignment ="Center" FontWeight ="Bold" />

   26          < Label Name ="lblPage4" Content ="4" Grid.Column ="5" MouseLeftButtonUp ="lblPage4_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   27          < Label Name ="lblPage5" Content ="5" Grid.Column ="6" MouseLeftButtonUp ="lblPage5_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   28          < Label Name ="lblNext" Content ="&gt;" Grid.Column ="7" MouseLeftButtonUp ="lblNext_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   29          < Label Name ="lblLast" Content ="&gt;&gt;" Grid.Column ="8" MouseLeftButtonUp ="lblLast_MouseLeftButtonUp" VerticalAlignment ="Center" HorizontalAlignment ="Center" Foreground ="Blue" Cursor ="Hand" />

   30          < Label Name ="lblPages" Content ="1/10" Grid.Column ="10" VerticalAlignment ="Center" HorizontalAlignment ="Center" />

   31      </ Grid >

   32  </ UserControl >

　　其设计图的效果如下：

　　4、更改Pager.xaml.cs的代码。具体代码请参考Eallies.OA系统的源代码。
　　这里仅仅列举隐藏和显示控件的方法。在符合一定条件的情况下，第一页、上一页、前两页、前一页、后一页、后两页、下一页、最后一页，这些控件可能显示也可能不显示。在不显示时，将容纳该控件的格的宽度设为0即可；在显示时，则设为Auto。

    1         private void SetVisible()

    2         {

    3             try

    4             {

    5                 (( Grid) this.lblFirst.Parent).ColumnDefinitions[0].Width = GridLength.Auto;

    6                 (( Grid) this.lblPrevious.Parent).ColumnDefinitions[1].Width = GridLength.Auto;

    7                 (( Grid) this.lblPage1.Parent).ColumnDefinitions[2].Width = GridLength.Auto;

    8                 (( Grid) this.lblPage2.Parent).ColumnDefinitions[3].Width = GridLength.Auto;

    9                 (( Grid) this.lblPage4.Parent).ColumnDefinitions[5].Width = GridLength.Auto;

   10                 (( Grid) this.lblPage5.Parent).ColumnDefinitions[6].Width = GridLength.Auto;

   11                 (( Grid) this.lblNext.Parent).ColumnDefinitions[7].Width = GridLength.Auto;

   12                 (( Grid) this.lblLast.Parent).ColumnDefinitions[8].Width = GridLength.Auto;

   13 

   14                 if ( this._PageIndex <= 1) (( Grid) this.lblFirst.Parent).ColumnDefinitions[0].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   15                 if ( this._PageIndex <= 1) (( Grid) this.lblPrevious.Parent).ColumnDefinitions[1].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   16                 if ( this._PageIndex - 2 <= 0) (( Grid) this.lblPage1.Parent).ColumnDefinitions[2].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   17                 if ( this._PageIndex - 1 <= 0) (( Grid) this.lblPage2.Parent).ColumnDefinitions[3].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   18                 if ( this._PageIndex + 1 >= this._PageCount + 1) (( Grid) this.lblPage4.Parent).ColumnDefinitions[5].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   19                 if ( this._PageIndex + 2 >= this._PageCount + 1) (( Grid) this.lblPage5.Parent).ColumnDefinitions[6].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   20                 if ( this._PageIndex + 1 >= this._PageCount + 1) (( Grid) this.lblNext.Parent).ColumnDefinitions[7].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   21                 if ( this._PageIndex >= this._PageCount) (( Grid) this.lblLast.Parent).ColumnDefinitions[8].Width = ( GridLength)( new GridLengthConverter()).ConvertFromString( "0");

   22             }

   23             catch

   24             {

   25                 throw;

   26             }

   27         }