利用ViewState和DataTable动态录入数据的例子
本例子是论坛上的网友提问的问题，由于经常会有人用到，就贴在这里，供初学者练习。
<%@ Page Language="C#" EnableViewState="true" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
private DataTable stoveTable = null;
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//创建 EmptyDataTemplate
this.GridView_list.DataBind();
}
}
protected void GridView_list_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
String usage = DataBinder.Eval(e.Row.DataItem, "usage").ToString();
String steelKind = DataBinder.Eval(e.Row.DataItem, "steelKind").ToString();
String castingTon = DataBinder.Eval(e.Row.DataItem, "castingTon").ToString();
DropDownList x1 = e.Row.FindControl("x1") as DropDownList;
DropDownList x2 = e.Row.FindControl("x2") as DropDownList;
TextBox x3 = e.Row.FindControl("x3") as TextBox;
x3.Text = castingTon;
ListItem xx1 = x1.Items.FindByValue(usage);
if (xx1 != null) xx1.Selected = true;
ListItem xx2 = x2.Items.FindByValue(steelKind);
if (xx2 != null) xx2.Selected = true;
}
}
protected void LinkButton1_Click(object sender, EventArgs e)
{
DropDownList x1, x2;
TextBox x3;
if (GridView_list.Rows.Count == 0)
{
x1 = GridView_list.Controls[0].Controls[0].FindControl("x1") as DropDownList;
x2 = GridView_list.Controls[0].Controls[0].FindControl("x2") as DropDownList;
x3 = GridView_list.Controls[0].Controls[0].FindControl("x3") as TextBox;
}
else
{
GridViewRow r = GridView_list.FooterRow;
x1 = r.FindControl("x1") as DropDownList;
x2 = r.FindControl("x2") as DropDownList;
x3 = r.FindControl("x3") as TextBox;
}
if (ViewState["dt"] == null)
{
stoveTable = new DataTable();
stoveTable.Columns.Add("usage", typeof(String));
stoveTable.Columns.Add("steelKind", typeof(String));
stoveTable.Columns.Add("castingTon", typeof(String));
}
else
{
stoveTable = (DataTable)ViewState["dt"];
}
DataRow newRow = stoveTable.NewRow();
newRow["usage"] = x1.SelectedValue;
newRow["steelKind"] = x2.SelectedValue;
newRow["castingTon"] = x3.Text;
stoveTable.Rows.Add(newRow);
ViewState["dt"] = stoveTable;
this.GridView_list.DataSource = stoveTable;
this.GridView_list.DataBind();
}
protected void LinkButton2_Click(object sender, EventArgs e)
{
if (ViewState["dt"] == null)
{
return;
}
stoveTable = (DataTable)ViewState["dt"];
if (stoveTable.Rows.Count < 1) return;
stoveTable.Rows.RemoveAt(stoveTable.Rows.Count - 1);
ViewState["dt"] = stoveTable;
this.GridView_list.DataSource = stoveTable;
this.GridView_list.DataBind();
}
protected void x1_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList x1 = sender as DropDownList;
GridViewRow r = x1.Parent.Parent as GridViewRow;
if (ViewState["dt"] == null)
{
Response.Write("Error");
return;
}
stoveTable = (DataTable)ViewState["dt"];
stoveTable.Rows[r.RowIndex]["usage"] = x1.SelectedValue;
ViewState["dt"] = stoveTable;
this.GridView_list.DataSource = stoveTable;
this.GridView_list.DataBind();
}
protected void x2_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList x2 = sender as DropDownList;
GridViewRow r = x2.Parent.Parent as GridViewRow;
if (ViewState["dt"] == null)
{
Response.Write("Error");
return;
}
stoveTable = (DataTable)ViewState["dt"];
stoveTable.Rows[r.RowIndex]["steelKind"] = x2.SelectedValue;
ViewState["dt"] = stoveTable;
this.GridView_list.DataSource = stoveTable;
this.GridView_list.DataBind();
}
protected void x3_TextChanged(object sender, EventArgs e)
{
TextBox x3 = sender as TextBox;
GridViewRow r = x3.Parent.Parent as GridViewRow;
if (ViewState["dt"] == null)
{
Response.Write("Error");
return;
}
stoveTable = (DataTable)ViewState["dt"];
stoveTable.Rows[r.RowIndex]["castingTon"] = x3.Text;
ViewState["dt"] = stoveTable;
this.GridView_list.DataSource = stoveTable;
this.GridView_list.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<asp:GridView ID="GridView_list" runat="server" ShowFooter="true" AutoGenerateColumns="false"
OnRowDataBound="GridView_list_RowDataBound">
<EmptyDataTemplate>
<table style="border-collapse: collapse; width: 100%" cellspacing="0" rules="all"
border="1">
<tr>
<th scope="col">
选择1
</th>
<th scope="col">
选择2
</th>
<th scope="col">
输入文字
</th>
</tr>
<tr><td>
<asp:DropDownList ID="x1" runat="server">
<asp:ListItem>L0</asp:ListItem>
<asp:ListItem>L1</asp:ListItem>
<asp:ListItem>L2</asp:ListItem>
<asp:ListItem>L3</asp:ListItem>
</asp:DropDownList>
</td><td>
<asp:DropDownList ID="x2" runat="server">
<asp:ListItem>10#</asp:ListItem>
<asp:ListItem>20#</asp:ListItem>
<asp:ListItem>30#</asp:ListItem>
<asp:ListItem>40#</asp:ListItem>
</asp:DropDownList>
</td><td>
<asp:TextBox ID="x3" runat="server"></asp:TextBox>
</td></tr>
</table>
</EmptyDataTemplate>
<Columns>
<asp:TemplateField HeaderText="选择1">
<ItemTemplate>
<asp:DropDownList ID="x1" runat="server" AutoPostBack="true" OnSelectedIndexChanged="x1_SelectedIndexChanged">
<asp:ListItem>L0</asp:ListItem>
<asp:ListItem>L1</asp:ListItem>
<asp:ListItem>L2</asp:ListItem>
<asp:ListItem>L3</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
<FooterTemplate>
<asp:DropDownList ID="x1" runat="server">
<asp:ListItem>L0</asp:ListItem>
<asp:ListItem>L1</asp:ListItem>
<asp:ListItem>L2</asp:ListItem>
<asp:ListItem>L3</asp:ListItem>
</asp:DropDownList>
</FooterTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="选择2">
<ItemTemplate>
<asp:DropDownList ID="x2" runat="server" AutoPostBack="true" OnSelectedIndexChanged="x2_SelectedIndexChanged">
<asp:ListItem>10#</asp:ListItem>
<asp:ListItem>20#</asp:ListItem>
<asp:ListItem>30#</asp:ListItem>
<asp:ListItem>40#</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
<FooterTemplate>
<asp:DropDownList ID="x2" runat="server">
<asp:ListItem>10#</asp:ListItem>
<asp:ListItem>20#</asp:ListItem>
<asp:ListItem>30#</asp:ListItem>
<asp:ListItem>40#</asp:ListItem>
</asp:DropDownList>
</FooterTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="输入文字">
<ItemTemplate>
<asp:TextBox ID="x3" runat="server" AutoPostBack="true" OnTextChanged="x3_TextChanged"></asp:TextBox>
</ItemTemplate>
<FooterTemplate>
<asp:TextBox ID="x3" runat="server"></asp:TextBox>
</FooterTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<asp:LinkButton ID="LinkButton1" runat="server" Text="添加内容" OnClick="LinkButton1_Click"></asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" Text="删除内容" OnClick="LinkButton2_Click"></asp:LinkButton>
</form>
</body>
</html>
下面采用另外一种方法，
<%@ Page Language="C#" AutoEventWireup="true" EnableViewState="true" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
private DataTable dataTable = null;
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
this.Bind(true);
}
}
private DataTable GetDataTable()
{
if (ViewState["dt"] == null)
{
dataTable = new DataTable();
dataTable.Columns.Add("usage", typeof(String));
dataTable.Columns.Add("steelKind", typeof(String));
dataTable.Columns.Add("castingTon", typeof(String));
return dataTable;
}
else
{
return ViewState["dt"] as DataTable;
}
}
private void Bind(bool AddBlankRow)
{
dataTable = GetDataTable();
if (AddBlankRow) dataTable.Rows.Add(dataTable.NewRow());
this.GridView1.DataSource = dataTable;
this.GridView1.DataBind();
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DropDownList x1 = e.Row.FindControl("x1") as DropDownList;
DropDownList x2 = e.Row.FindControl("x2") as DropDownList;
TextBox x3 = e.Row.FindControl("x3") as TextBox;
String usage = DataBinder.Eval(e.Row.DataItem, "usage").ToString();
String steelKind = DataBinder.Eval(e.Row.DataItem, "steelKind").ToString();
String castingTon = DataBinder.Eval(e.Row.DataItem, "castingTon").ToString();
x3.Text = castingTon;
ListItem xx1 = x1.Items.FindByValue(usage);
if (xx1 != null) xx1.Selected = true;
ListItem xx2 = x2.Items.FindByValue(steelKind);
if (xx2 != null) xx2.Selected = true;
}
}
protected void LinkButton1_Click(object sender, EventArgs e)
{
//总是取最后的一行
GridViewRow row = GridView1.Rows[GridView1.Rows.Count - 1];
DropDownList x1 = row.FindControl("x1") as DropDownList;
DropDownList x2 = row.FindControl("x2") as DropDownList;
TextBox x3 = row.FindControl("x3") as TextBox;
dataTable = this.GetDataTable();
DataRow newRow = dataTable.NewRow();
if (dataTable.Rows.Count > 0)
{
newRow = dataTable.Rows[dataTable.Rows.Count - 1];
}
newRow["usage"] = x1.SelectedValue;
newRow["steelKind"] = x2.SelectedValue;
newRow["castingTon"] = x3.Text;
if (dataTable.Rows.Count == 0)
{
dataTable.Rows.Add(newRow);
}
ViewState["dt"] = dataTable;
this.Bind(true);
}
protected void LinkButton2_Click(object sender, EventArgs e)
{
dataTable = this.GetDataTable();
if (dataTable.Rows.Count < 1) return;
dataTable.Rows.RemoveAt(dataTable.Rows.Count - 1);
ViewState["dt"] = dataTable;
this.Bind(false);
}
protected void x1_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList x1 = sender as DropDownList;
GridViewRow r = x1.Parent.Parent as GridViewRow;
dataTable = this.GetDataTable();
dataTable.Rows[r.RowIndex]["usage"] = x1.SelectedValue;
ViewState["dt"] = dataTable;
this.Bind(false);
}
protected void x2_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList x2 = sender as DropDownList;
GridViewRow r = x2.Parent.Parent as GridViewRow;
dataTable = this.GetDataTable();
dataTable.Rows[r.RowIndex]["steelKind"] = x2.SelectedValue;
ViewState["dt"] = dataTable;
this.Bind(false);
}
protected void x3_TextChanged(object sender, EventArgs e)
{
TextBox x3 = sender as TextBox;
GridViewRow r = x3.Parent.Parent as GridViewRow;
dataTable = this.GetDataTable();
dataTable.Rows[r.RowIndex]["castingTon"] = x3.Text;
ViewState["dt"] = dataTable;
this.Bind(false);
}
protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if (e.Row.RowIndex < this.GetDataTable().Rows.Count - 1)
{
DropDownList x1 = e.Row.FindControl("x1") as DropDownList;
DropDownList x2 = e.Row.FindControl("x2") as DropDownList;
TextBox x3 = e.Row.FindControl("x3") as TextBox;
x1.AutoPostBack = x2.AutoPostBack = x3.AutoPostBack = true;
x1.SelectedIndexChanged += new EventHandler(x1_SelectedIndexChanged);
x2.SelectedIndexChanged += new EventHandler(x2_SelectedIndexChanged);
x3.TextChanged += new EventHandler(x3_TextChanged);
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowDataBound="GridView1_RowDataBound"
OnRowCreated="GridView1_RowCreated">
<Columns>
<asp:TemplateField HeaderText="选择1">
<ItemTemplate>
<asp:DropDownList ID="x1" runat="server">
<asp:ListItem>L0</asp:ListItem>
<asp:ListItem>L1</asp:ListItem>
<asp:ListItem>L2</asp:ListItem>
<asp:ListItem>L3</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="选择2">
<ItemTemplate>
<asp:DropDownList ID="x2" runat="server">
<asp:ListItem>10#</asp:ListItem>
<asp:ListItem>20#</asp:ListItem>
<asp:ListItem>30#</asp:ListItem>
<asp:ListItem>40#</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="输入文字">
<ItemTemplate>
<asp:TextBox ID="x3" runat="server"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<asp:LinkButton ID="LinkButton1" runat="server" Text="添加内容" OnClick="LinkButton1_Click"></asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" Text="删除内容" OnClick="LinkButton2_Click"></asp:LinkButton>
</form>
</body>
</html>