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
Width="100%" DataKeyNames="EmployeeID" OnPageIndexChanging="GridView1_PageIndexChanging" OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" OnSorting="GridView1_Sorting" PageSize="3" OnRowCancelingEdit="GridView1_RowCancelingEdit" OnRowCommand="GridView1_RowCommand">
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 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();
}
}