asp.net 2.0下一個標準GRIDVIEW功能的實現（不用datasource控制項）-.NET教程,Asp.Net開發

在asp.net 2.0下，gridview是十分方便的了，加一個datasource系列的控制項的話，就可以馬上和gridview綁定，十分方便。但其實也可以
使用datatable或者dataview的，這個時候就不是用datasource系列控制項了。下面講下如何在asp.net 2.0下，實現gridview控制項的翻頁，各列排序，
編輯的功能。
    首先，我們讀取的是northwind資料庫中的employee表。放置一個gridview後，添加幾個綁定的列，代碼如下
 <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，我們要實現分頁，把allowpaging設定為true,並設定每頁的分頁條數，最後在codebehind中寫入
protected void gridview1_pageindexchanging(object sender, gridviewpageeventargs e)
    {
        gridview1.pageindex = e.newpageindex;
        bindgrid();
    }
  為了實現每列都可以自動點擊排序，可以設定allowsorting=true,然後設定onsorting="gridview1_sorting"，其中gridview_sorting
代碼為
  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();
    }
很明顯，設定viewsate來儲存每次排序時的順序，上面的相信很容易理解。
     最後，實現編輯功能，因為在aspx頁面中已經設定了onrowediting="gridview1_rowediting"，其中gridview1_rowediting的代碼為
 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 firstname=@fname,lastname=@lname where employeeid=@empid", 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，上面的代碼和asp.net 1.1版本的其實原理是差不多的。最後，bindgrid()的過程很簡單，為綁定咯
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();

這裡gridview綁定的是dataview,並且用dv.sort設定了每次排序的順序，也就是說，每次排序後其順序都是保持不變的。
當然最後是page_load事件咯
   protected void page_load(object sender, eventargs e)
    {
        if(!ispostback)
        {
            bindgrid();
        }
    }