asp.net 2.0下一个标准GRIDVIEW功能的实现

在asp.net 2.0下，gridview是十分方便的了，加一个datasource系列的控件的话，就可以马上和gridview绑定，十分方便。但其实也可以
使用datatable或者dataview的，这个时候就不是用datasource系列控件了。下面讲下如何在asp.net 2.0下，实现gridview控件的翻页，各列排序，
编辑的功能。
    首先，我们读取的是northwind数据库中的employee表。放置一个gridview后，添加几个绑定的列，代码如下
 <asp:gridview id="gridview1" runat="server" allowpaging="true" allowsorting="true"
            autogeneratecolumns="false" cellpadding="4" forecolor="#333333" gridlines="none"
            width="100%" datakeynames="employeeid" onpageindexchanging="gridview1_pageindexchanging" onrowediting="gridview1_rowediting" onrowupdating="gridview1_rowupdating" onsorting="gridview1_sorting" pagesize="3" onrowcancelingedit="gridview1_rowcancelingedit" onrowcommand="gridview1_rowcommand">
            <footerstyle backcolor="#990000" font-bold="true" forecolor="white" />
            <columns>
                <asp:boundfield datafield="employeeid" headertext="employee id" readonly="true" />
                <asp:boundfield datafield="firstname" headertext="first name" sortexpression="firstname" />
                <asp:boundfield datafield="lastname" headertext="last name" sortexpression="lastname" />
                <asp:commandfield showeditbutton="true" />
            </columns>
            <rowstyle backcolor="#fffbd6" forecolor="#333333" />
            <selectedrowstyle backcolor="#ffcc66" font-bold="true" forecolor="navy" />
            <pagerstyle backcolor="#ffcc66" forecolor="#333333" horizontalalign="center" />
            <headerstyle backcolor="#990000" font-bold="true" forecolor="white" />
            <alternatingrowstyle backcolor="white" />
        </asp:gridview>

首先，我们要实现分页，把allowpaging设置为true,并设置每页的分页条数，最后在codebehind中写入
protected void gridview1_pageindexchanging(object sender, gridviewpageeventargs e)
    {
        gridview1.pageindex = e.newpageindex;
        bindgrid();
    }
  为了实现每列都可以自动点击排序，可以设置allowsorting=true,然后设置onsorting="gridview1_sorting"，其中gridview_sorting
代码为
  protected void gridview1_sorting(object sender, gridviewsorteventargs e)
    {
        viewstate["sortexpression"] = e.sortexpression;

        if (viewstate["sortdirection"] == null)
        {
            viewstate["sortdirection"] = "asc";
        }
        else
        {
            if (viewstate["sortdirection"].tostring() == "asc")
            {
                viewstate["sortdirection"] = "desc";
            }
            else
            {
                viewstate["sortdirection"] = "asc";
            }
        }
        bindgrid();
    }
很明显，设置viewsate来保存每次排序时的顺序，上面的相信很容易理解。
     最后，实现编辑功能，因为在aspx页面中已经设置了onrowediting="gridview1_rowediting"，其中gridview1_rowediting的代码为
 protected void gridview1_rowupdating(object sender, gridviewupdateeventargs e)
    {
        int empid;
        string fname, lname;
        empid = int.parse(gridview1.rows[e.rowindex].cells[0].text);
        fname = ((textbox)gridview1.rows[e.rowindex].cells[1].controls[0]).text;
        lname = ((textbox)gridview1.rows[e.rowindex].cells[2].controls[0]).text;

        sqlconnection cnn = new sqlconnection(@"data source=localhost;initial catalog=northwind;user id=sa;password=123456");
        cnn.open();
        sqlcommand cmd = new sqlcommand("update employees set [email protected],[email protected] where [email protected]", cnn);
        cmd.parameters.add(new sqlparameter("@fname",fname));
        cmd.parameters.add(new sqlparameter("@lname", lname));
        cmd.parameters.add(new sqlparameter("@empid", empid));
        cmd.executenonquery();
        cnn.close();

        gridview1.editindex = -1;
        bindgrid();
    }
    protected void gridview1_rowediting(object sender, gridviewediteventargs e)
    {
        gridview1.editindex = e.neweditindex;
        bindgrid();
    }
    protected void gridview1_rowcancelingedit(object sender, gridviewcancelediteventargs e)
    {
        gridview1.editindex = -1;
        bindgrid();
    }

  可以看到，上面的代码和asp.net 1.1版本的其实原理是差不多的。最后，bindgrid()的过程很简单，为绑定咯
dataset ds = new dataset();
        sqldataadapter da = new sqldataadapter("select * from employees", @"data source=localhost;initial catalog=northwind;user id=sa;password=123456");
        da.fill(ds,"employees");
        dataview dv = ds.tables[0].defaultview;

        if (viewstate["sortexpression"] != null)
        {
            dv.sort = viewstate["sortexpression"].tostring() + " " + viewstate["sortdirection"].tostring();
        }

        gridview1.datasource=dv;
        gridview1.databind();

这里gridview绑定的是dataview,并且用dv.sort设定了每次排序的顺序，也就是说，每次排序后其顺序都是保持不变的。
当然最后是page_load事件咯
   protected void page_load(object sender, eventargs e)
    {
        if(!ispostback)
        {
            bindgrid();
        }
    }