1
我正在嘗試創建一個GridView，它將包含用戶和他們有權訪問的權限級別的列表。每行都有以下字段：User_ID，Username，Permission1，Permission2，...，PermissionN，其中如果用戶沒有該權限，則權限值的值爲「0」，如果他們這樣做，則爲「1」由DAL返回的列不是名爲Permission1，而是實際的權限名稱）。我想通過使用複選框來表示數據，以允許管理員一次性向大量用戶快速授予或撤銷權限。在Dynamic GridView中保留CheckBox的值TemplateField
因爲我不知道手頭的權限數量，所以我動態地創建了TemplateFields和CheckBoxes，並且這個工作正常; GridView會顯示所有用戶的當前權限級別。當我嘗試根據用戶檢查和取消選中框來更新權限時，我遇到了問題。
一旦用戶完成更改權限，我有一個「更新」按鈕，這當然會導致回發。由於回發發生在OnClick事件之前，到達OnClick時，所有複選框已被重置爲其初始值。有沒有辦法我可以在發生回發之前獲取CheckBoxes的Checked屬性的值？是否有另一種（更好）的方式來做到這一點？謝謝。
ASPX：
<asp:GridView ID="gvUsers" runat="server" AutoGenerateColumns="False"
EnableModelValidation="True" DataKeyNames="ID">
</asp:GridView>
<asp:ObjectDataSource ID="odsUsers" runat="server" SelectMethod="GET_USERS"
TypeName="oDAL">
</asp:ObjectDataSource>
<asp:Button ID="btnUpdate" runat="server" Text="Update Permissions" OnClick="btnUpdate_OnClick"/>
代碼背後：
private static string[] excludeCols = { "ID", "Username" };
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack) // Removing the IsPostBack check refreshes the GridView when the Update button is clicked
bindGridViewWithHiddenID(gvUsers, ((DataView)odsUsers.Select()).Table, excludeCols);
}
public static bool bindGridViewWithHiddenID(GridView gv, DataTable dt, string[] excludeCols)
{
gv.Columns.Clear();
gv.DataBind();
if (gv != null && dt != null && dt.Rows.Count > 0)
{
DataControlField newField;
foreach (DataColumn column in dt.Columns)
{
if (excludeCols.Contains(column.ColumnName))
{
newField = new BoundField();
((BoundField)newField).DataField = column.ColumnName;
}
else
{
newField = new TemplateField();
((TemplateField)newField).ItemTemplate = new CustomTemplate(column.ColumnName);
}
newField.HeaderText = column.ColumnName;
if (column.ColumnName == "ID" || column.ColumnName.EndsWith("_ID"))
newField.Visible = false;
gv.Columns.Add(newField);
}
gv.DataSource = dt;
gv.DataBind();
return true;
}
return false;
}
// By this time execution reaches here the CheckBoxes have already been reset
protected void btnUpdate_Click(object sender, EventArgs e)
{
...
}
CustomTemplate類：
public class CustomTemplate : ITemplate
{
private string binding;
private static int count = 0;
public CustomTemplate(string colNameBinding)
{
binding = colNameBinding;
}
public void InstantiateIn(Control container)
{
CheckBox chk = new CheckBox();
chk.ID = "chk" + count++;
chk.DataBinding += new EventHandler(this.chk_OnDataBinding);
container.Controls.Add(chk);
}
public void chk_OnDataBinding(object sender, EventArgs e)
{
CheckBox chk = (CheckBox)sender;
GridViewRow namingContainer = (GridViewRow)chk.NamingContainer;
DataRowView dataRow = (DataRowView)namingContainer.DataItem;
if (dataRow[binding].ToString() == "1")
chk.Checked = true;
else
chk.Checked = false;
}