[英]Dynamically generated controls not being found via FindControl
我有一個asp:panel
,單擊按鈕時,會動態添加一些復選框。
在另一個按鈕上單擊,我需要查看這些復選框並檢查是否已選中。
我找不到控件。 我嘗試使用提供的ID和ClientID進行FindControl。
復選框所在的面板的標記,以及兩個按鈕:
<asp:Panel runat="server" ScrollBars="Vertical" ID="pnlEmailCheckboxes" Height="150">
<br/>
<asp:CheckBox runat="server" Text="Other" ID="cbOtherEmail"/>
<asp:TextBox ID="txtOtherEmail" runat="server" Style="width: 270px;" CssClass="textbox-default"></asp:TextBox>
<br/>
</asp:Panel>
<asp:LinkButton ID="btnSendEmail" Text="<span>Send Email</span>" runat="server" CssClass="page-footer-button-highlight" OnClick="btnSendEmail_Click"></asp:LinkButton>
<asp:LinkButton ID="btnCloseEmail" Text="<span>Close</span>" runat="server" CssClass="page-footer-button" CausesValidation="false" OnClick="btnCloseEmail_OnClick"></asp:LinkButton>
生成文本框的事件:
protected void btnEmail_Click(object sender, EventArgs e)
{
List<CheckBox> cbList = new List<CheckBox>();
for (int i = 0; i < 10; i++)
{
CheckBox cb = new CheckBox();
cb.Text = "text" + i;
cb.ID = Guid.newGuid().ToString();
cb.ClientIDMode = ClientIDMode.Static;
pnlEmailCheckboxes.Controls.AddAt(0, cb);
pnlEmailCheckboxes.Controls.AddAt(0, new LiteralControl("<br/>"));
cbList.Add(cb);
}
Session["checkboxes"] = cbList;
mpeEmail.Show();
}
嘗試檢索文本框的按鈕(不起作用):
protected void btnSendEmail_Click(object sender, EventArgs e)
{
//the email recipients
List<string> emailRecipients = new List<string>();
List<CheckBox> cbList = (List<CheckBox>)Session["checkboxes"];
foreach (CheckBox cb in cbList)
{
CheckBox cbClient = (CheckBox) pnlEmailCheckboxes.FindControl(cb.ClientID); //I've also tried to find it by cb.ID
//null reference here, the checkbox cbClient was not found
if (cbClient.Checked) emailRecipients.Add(cb.Text.Trim());
}
//Ive also tried this, it does not contain the dynamically generated checkboxes
//var cbControls = pnlEmailCheckboxes.Controls.OfType<CheckBox>();
}
編輯:
客戶端html甚至顯示,其ID與我要搜索的ID匹配。
<input id="00e3a485-2083-4ef8-810b-6ed4fb1f62f9" type="checkbox" name="ctl00$Body$00e3a485-2083-4ef8-810b-6ed4fb1f62f9">
嘗試向每個動態控件添加唯一的ID並設置ClientIDMode = ClientIDMode.Static
:
List<CheckBox> cbList = new List<CheckBox>();
for (int i = 0; i < 10; i++)
{
CheckBox cb = new CheckBox();
cb.ID = "DynamicCb" + i";
cb.ClientIDMode = ClientIDMode.Static;
cb.Text = "text" + i;
pnlEmailCheckboxes.Controls.AddAt(0, cb);
pnlEmailCheckboxes.Controls.AddAt(0, new LiteralControl("<br/>"));
cbList.Add(cb);
}
我已經找到解決問題的方法。 如果將控件添加到OnInit方法中,則可以看到稍后單擊按鈕的復選框。
protected override void OnInit(EventArgs e)
{
List<CheckBox> cbList = new List<CheckBox>();
for (int i = 0; i < 10; i++)
{
CheckBox cb = new CheckBox();
cb.Text = "text" + i;
cb.ID = Guid.newGuid().ToString();
pnlEmailCheckboxes.Controls.AddAt(0, cb);
pnlEmailCheckboxes.Controls.AddAt(0, new LiteralControl("<br/>"));
cbList.Add(cb);
}
Session["checkboxes"] = cbList;
}
現在存在另一個問題,即使在UI上選中了每個復選框,每個復選框也始終具有Checked == False。 但是,這是另一個問題的原因。
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