手把手教你如何扩展GridView之自动排序篇

一时失言乱红尘 2021-09-30 12:06 307阅读 0赞

最新重构源码下载：[打造0代码全自动GridView-天具神力][0_GridView-]       
        
看到这两天园子里面“强奸”GridView的兄弟们可真不少，自己也手痒，也凑凑热闹，写得好，大家鼓励鼓励，写的不好，大家多多指教。  
   首先说说本文要实现的目的，大家都知道GridView支持排序，但是每次排序的时候，都需要给GridView添加OnSorting事件，这么繁琐而费力，作为世界上最最聪明的程序员的我们难道没有抱怨么？废话少说，不才想到了一种解决这个问题的方法，可以让大家一劳永逸。下面就让兄弟我臭摆一下，希望园子里面的高高手，大大牛们给给面子，捧捧场，别取消兄弟。  
   首先创建一个GridViewEx的类，并继承GridView,然后添加如下委托

![None.gif][] public   delegate   void  BindEventHandler();

在GridViewEx中添加如下代码:

![None.gif][] DataSet \_ds;  
![None.gif][]        \[Description( " 自定义的DataSet类型数据源 " ),Category( " 扩展 " )\]  
![None.gif][]         public   virtual  DataSet DataSetSource  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            get  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                return \_ds;  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            set  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                \_ds = value;  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}

我们在使用GridViewEx的时候，就只需要设定DataSetSource属性，这个将限定本扩展组件只支持DataSet类型的数据源，其他类型数据源有兴趣的，大家可以进行扩展，象ArrayList,List<>这些都是可以的。  
接下来的工作是为GridViewEx添加OnBind事件，如下：

![None.gif][]   public   event  BindEventHandler Bind;  
![None.gif][]         public   virtual   void  OnBind()  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            if (Bind != null)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                Bind();  
![InBlock.gif][]                if (DataSetSource != null)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    DataView dv = DataSetSource.Tables\[0\].DefaultView;  
![InBlock.gif][]                    dv.Sort = SortExpressionStr;                    
![InBlock.gif][]                    this.DataSource = dv;  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][]                    this.DataBind();                \}  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}

有了这个事件，我们就可以让GridView去类外部获取数据源，然后回到类本身来组织数据和进行绑定了。  
接下来，需要声明两个方法

![None.gif][]   \[Description( " 排序表达式 " ),Category( " 扩展 " )\]  
![None.gif][]         protected   virtual   string  SortExpressionStr  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            get  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                if (ViewState\["SortExpression"\] == null)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    return null;  
![ExpandedSubBlockEnd.gif][]                \}  
![InBlock.gif][]                return ViewState\["SortExpression"\].ToString();  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            set  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                ViewState\["SortExpression"\] = value;  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}   
![None.gif][]        \[Description( " 排序方向 " ),Category( " 扩展 " )\]  
![None.gif][]         protected   virtual   string  SortDirectionStr  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            get  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                if (ViewState\["SortDirection"\] == null)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    return "DESC";  
![ExpandedSubBlockEnd.gif][]                \}  
![InBlock.gif][]                if (ViewState\["SortDirection"\].ToString().ToLower() != "asc" && ViewState\["SortDirection"\].ToString().ToLower() != "desc")  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    return "DESC";  
![ExpandedSubBlockEnd.gif][]                \}  
![InBlock.gif][]                return ViewState\["SortDirection"\].ToString();  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            set  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                ViewState\["SortDirection"\] = value;  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}

和下面的属性

![None.gif][]   public   string  SortExpressionEx  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            get  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                if (ViewState\["SortExpressionEx"\] == null)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    return null;  
![ExpandedSubBlockEnd.gif][]                \}  
![InBlock.gif][]                return ViewState\["SortExpressionEx"\].ToString();  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            set  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                ViewState\["SortExpressionEx"\] = value;  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}

然后重写OnSorting事件如下:

![None.gif][]    protected   override   void  OnSorting(GridViewSortEventArgs e)  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            SortExpressionEx = e.SortExpression;  
![InBlock.gif][]            SortExpressionStr = e.SortExpression \+ " " \+ SortDirectionStr;  
![InBlock.gif][]            OnBind();  
![InBlock.gif][]            if (SortDirectionStr.ToLower() == "asc")  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                SortDirectionStr = "DESC";  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            else  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                SortDirectionStr = "ASC";  
![ExpandedSubBlockEnd.gif][]            \}  
![ExpandedBlockEnd.gif][]        \}

并且增加如下的OnLoad事件

![None.gif][]   protected   override   void  OnLoad(EventArgs e)  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][]         ![dot.gif][] \{  
![InBlock.gif][]            if (!Page.IsPostBack)  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]            ![dot.gif][]\{  
![InBlock.gif][]                try  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]                    OnBind();  
![ExpandedSubBlockEnd.gif][]                \}  
![InBlock.gif][]                catch  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]                ![dot.gif][]\{  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][]                \}  
![ExpandedSubBlockEnd.gif][]            \}  
![InBlock.gif][]            base.OnLoad(e);  
![ExpandedBlockEnd.gif][]        \}

经过上面这样简单的改造，您再次使用GridViewEx的时候，在前台页面使用的时候，您只要按照这样的格式就可以了：  
<cc1:GridViewEx id="gridViewEx1" OnBind="BindData" runat="server" AllowSorting="True">  
  <Columns>  
    <asp:TemplateField HeaderText="序号" SortExpression="ID"><%\#Eval(''ID")%></asp:TemplateField>   
 </Columns>  
</cc1:GridViewEx>  
 后台只需要添加这样的方法

![None.gif][] public   void  BindData()  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][] ![dot.gif][] \{  
![InBlock.gif][]   DataSet ds = new DataSet();  
![InBlock.gif][]   ds = ![dot.gif][]//获得DataSet;  
![InBlock.gif][]   gridView1.DataSetSource = ds;  
![ExpandedBlockEnd.gif][]\}

在页面中的Page\_Load方法中，也不用再写  
if(!Page.IsPostBack)  
\{  
        BindData();//绑定GridView的方法  
\}  
注意，如果需要重新绑定GridView，只需要这样GridViewEx1.OnBind();即可。

转载于:https://www.cnblogs.com/jillzhang/archive/2007/06/04/771139.html

[0_GridView-]: http://www.cnblogs.com/jillzhang/archive/2007/10/14/923926.html
[None.gif]: /images/20210724/30c2bb1b7323493a961aadbff1b0b7ff.png
[ExpandedBlockStart.gif]: https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif
[ContractedBlock.gif]: https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif
[dot.gif]: /images/20210724/32f136204706465ba84c2449203cfa27.png
[InBlock.gif]: /images/20210724/d472c4f0dc7b4307b3ed451ac1147cc1.png
[ExpandedSubBlockStart.gif]: https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif
[ContractedSubBlock.gif]: https://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif
[ExpandedSubBlockEnd.gif]: /images/20210724/4a4cfaf8bc14494da4cec8318eb3968e.png
[ExpandedBlockEnd.gif]: /images/20210724/bbff2be3b59b487b8c28198e171e85a5.png