我有一個資料串列，其中填充了資料庫中的值。當用戶單擊復選框時，我想遍歷所有資料串列項并隱藏所有具有屬性 isActive = false（在文本標簽中顯示為“已禁用”）的項。專案模板由一個包含多個其他專案、按鈕等的表格組成，下面沒有包含這些專案。因此，我想隱藏在特定專案的 itemtemplate 下找到的所有元素。
我的想法是通過訪問其 id 來隱藏整個表，然后將表的可見屬性設定為 false。當我運行代碼時，這目前沒有做任何事情。任何幫助將不勝感激！
<asp:CheckBox runat="server" Text="Filter by active postings" OnCheckedChanged="filterByActive"/>
<asp:DataList ID="postingsDataList" runat="server" OnItemCommand="itemCommand" >
<ItemTemplate>
<div class="postingRow">
<table class="postingTable" id="posting">
<tr>
<td>
<asp:Label ID="lblActive" runat="server" Text=<%#Eval("isActive").ToString().Equals("True") ? "Active ✅" : "Disabled ❌"%>/>
</td>
</tr>
</table>
</div>
</ItemTemplate>
</asp:DataList>
背后的代碼：
protected void filterByActive (object sender, EventArgs e)
{
int count = postingsDataList.Items.Count;
CheckBox check = (CheckBox)sender;
if (check.Checked == true)
{
for (int i = 0; i < count; i )
{
Label lblActive = postingsDataList.Items[i].FindControl("lblActive") as Label;
string isActive = lblActive.Text.ToString();
if (isActive.Equals("Disabled ❌"))
{
Table tbl = postingsDataList.Items[i].FindControl("posting") as Table;
tbl.Visible = false;
}
}
}
else
{
for (int i = 0; i < count; i )
{
Label lblActive = postingsDataList.Items[i].FindControl("lblActive") as Label;
string isActive = lblActive.Text.ToString();
if (isActive.Equals("Active ✅"))
{
Table tbl = postingsDataList.Items[i].FindControl("posting") as Table;
tbl.Visible = true;
}
}
}
}
}
uj5u.com熱心網友回復：
好的，我建議你這樣做：
保留您的表 - 因此您不必再次訪問 sql server。（但是，你可以 - 不是世界末日）。
我沒有你的資料，但我有一個簡單的酒店串列 - 酒店有一個活動列。因此，讓我們根據選中的復選框過濾資料，而不必再次訪問資料庫服務器。更好的是，如果我們取消選中該框，我們可以顯示我們擁有的所有記錄。
我們當然假設這不是很多資料。
好的，所以我們有這個用于我們的標記：
（真的無所謂很多）
<asp:DataList ID="DataList1" runat="server" DataKeyField="ID" RepeatColumns="4" RepeatDirection="Horizontal" >
<ItemTemplate>
<div style="border-style:solid;color:black;width:300px;">
<div style="padding:5px;text-align:right">
<p>Hotel Name: <asp:TextBox ID="HotelName" runat="server" Text ='<%# Eval("HotelName") %>' /></p>
<p>First Name: <asp:TextBox ID="FirstName" runat="server" Text ='<%# Eval("FirstName") %>' /></p>
<p>Last Name: <asp:TextBox ID="LastName" runat="server" Text ='<%# Eval("LastName") %>' /></p>
<p>City: <asp:TextBox ID="City" runat="server" Text ='<%# Eval("City") %>' /></p>
<p>Province: <asp:TextBox ID="Province" runat="server" Text ='<%# Eval("Province") %>' /></p>
Active: <asp:CheckBox ID="Active" runat="server" Checked = '<%# Eval("Active") %>'/>
</div>
</div>
</ItemTemplate>
</asp:DataList>
現在，我們要加載的代碼可能是這樣的：
DataTable rstData = new DataTable();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
LoadData();
ViewState["MyData"] = rstData;
}
else
rstData = (DataTable)ViewState["MyData"];
}
void LoadData()
{
using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
{
string strSQL = "SELECT top 10 * from tblHotels ORDER BY HotelName";
using (SqlCommand cmdSQL = new SqlCommand(strSQL, conn))
{
conn.Open();
rstData.Load(cmdSQL.ExecuteReader());
DataList1.DataSource = rstData;
DataList1.DataBind();
}
}
}
現在我們有了這個：
現在，我們的過濾器顯示/隱藏變成了這樣：
protected void ckFilter_CheckedChanged(object sender, EventArgs e)
{
// filter based on check box
if (ckFilter.Checked)
rstData.DefaultView.RowFilter = "Active = 1";
else
rstData.DefaultView.RowFilter = "";
DataList1.DataSource = rstData;
DataList1.DataBind();
}
更好的是，如果我取消選中該復選框，則會重新顯示所有資料。而且我們不必重新點擊資料庫來做到這一點！！！
現在，我們也可以只隱藏/顯示每一行，然后如果出于某種原因您不想像我上面那樣保留資料表，則取消隱藏。
檢查框過濾器：
As noted, if I un-check the box, then I get all the data back - all without hitting the database again.
Edit:=========================================
Note that if you NOT using the above horizontal across, but just rows down?
Then you can just as well format to hide/show the rows, and you do NOT have to persist the data table.
You can apply formatting say by doing this:
protected void ckFilter_CheckedChanged(object sender, EventArgs e)
{
foreach (DataListItem gRow in DataList1.Items)
{
// get checkbox
CheckBox ckActive = (CheckBox)gRow.FindControl("Active");
// get div
HtmlGenericControl Myiv = (HtmlGenericControl)gRow.FindControl("myrow");
string MyFormat = "normal";
if (ckFilter2.Checked)
{
// only show active ones
if (ckActive.Checked)
MyFormat = "normal";
else
MyFormat = "none";
}
Myiv.Style["display"] = MyFormat;
}
}
So the above does work fine. BUT the restriction is that you can't have a set of horizontal across data items like my original screen shot (it actually still works but in fact hide each panel with a blank space).
So, if your as noted using vertical layout (and it looks to be that you are).
Note for above, I added a simple ID to the "div", and runat server like this:
<ItemTemplate>
<div id="myrow" runat="server"
style="border-style:solid;color:black;width:300px;">
Then skip my first example. You can loop the data list rows, and hide, or un-hide. And even more amazing is that if you un-hide - then the rows all do re-appear and persist correct.
I had pulled a working example - but I was trying to figure out why I had to persist the data - the reason was the "horizontail" across settings.
But, as above shows, no real need to persist the data source table - you can process the data list rows, and hide/show each one conditionals, and you can do this without a data re-bind.
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