这个问题反复在论坛出现，其实这个问题在MSDN上早就有答案
1。英文版:Top Questions about the DataGrid Web Server Control(Mike Pope and Nikhil Kothari)
2。中文版:DataGrid Web 伺服器控制项的常见问题
可惜，论坛上的风气不太好，你即使给了连接，真正去看的人大概并不多
诀窍是，如果动态添加了列的话，需要在下一次PostBack时，在LoadViewState或更早把这些列重新添加。原因是，在Page类递归调用LoadViewState时，会调用DataGrid的CreateChildControls，而DataGrid的(实际上是它的父类的实现)CreateChildControls会调用DataGrid的CreateControlHierarchy()方法。在其中，DataGrid会根据当前的列的数目构造DataGridItem里的东西，然后从ViewState里恢复原来的数据。如果你没有重新添加你的动态列的话，你的动态列在PostBack后就会消失，更不用谈触发列里的控件的事件了
检验你的动态控件在PostBack后是否还在的一个方法是，加一个按钮看PostBack后的行为
下面是一个简单的测试
<html>
<body>
<form runat=”server”>
<asp:DataGrid id=”DataGrid1″ runat=”server”
GridLines=”Both” AutoGenerateColumns=”false”
OnItemCommand=”DataGrid1_ItemCommand”>
<Columns>
<asp:ButtonColumn HeaderText=”Static Button” Text=”Click Me”
CommandName=”Static”/>
<asp:TemplateColumn HeaderText=”Data”>
<ItemTemplate><%#Container.DataItem%></ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<asp:Button id=”btnAddAColumn” runat=”server” Text=”Add a column” OnClick=”AddButtonColumn”/>
<asp:Button id=”btnRefresh” runat=”server” Text=”Refresh” />
</form>
</body>
</html>
void BindGrid()
{
DataGrid1.DataSource = new string[] {“a”,”b”,”c”};
DataGrid1.DataBind();
}
void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGrid();
}
}
void DataGrid1_ItemCommand(Object sender, DataGridCommandEventArgs e)
{
Response.Write(“ItemCommand is called
“);
LinkButton btn = e.CommandSource as LinkButton;
if (btn != null)
Response.Write(String.Format(“{0} is clicked on row {1}”, btn.CommandName, e.Item.ItemIndex));
}
//lifted from the original post
public void CreateGridColumn(DataGrid OperationDataGrid)
{
ButtonColumn NewButCol = new ButtonColumn() ;
NewButCol.Text = “编辑” ;
NewButCol.HeaderText = “操作” ;
NewButCol.CommandName = “Edit” ;
NewButCol.ButtonType = ButtonColumnType.LinkButton;
NewButCol.Visible = true ;
OperationDataGrid.Columns.Add(NewButCol) ;
//OperationDataGrid.Columns.AddAt(1,NewButCol) ;
}
bool ButtonAdded
{
get {
object o = ViewState[“ButtonAdded”];
if (o == null)
return false;
else return (bool)o;
}
set { ViewState[“ButtonAdded”] = value;}
}
void AddButtonColumn(object sender, EventArgs e)
{
CreateGridColumn(DataGrid1);
ButtonAdded = true;
BindGrid();
btnAddAColumn.Visible = false;
}
protected override void LoadViewState(object savedState)
{
base.LoadViewState(savedState);
//在这里重新添加，假如已经添加的话
if (ButtonAdded)
CreateGridColumn(DataGrid1);
}
