我是stackoverflow的新手，如果我错过了什么，请不要犹豫地评论。
所以，这是我的问题。
我试图在我的可编辑网格视图中包含一个签名画布，我尝试了许多不同的解决方案，但画布从来没有工作。我试过一次把它从gridview里放出来，没想到，签名就能用了，但是，只要我点击箭头进行编辑，画布就停止工作了，即使它不在gridview里。
有什么原因吗？
这里是我的代码，我没有包括所有的内容，如果你需要更多的内容，请问。
ps：gridview中的其他所有东西都在工作，而且显示没有问题。
ASP.NET
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
<asp:UpdatePanel ID="Panel1" runat="server">
<ContentTemplate> <%--runat="server">--%>
<asp:GridView
ID="GridView2"
runat="server"
GridLines="None"
AutoGenerateColumns="False"
CellPadding="6"
CssClass="mGrid"
OnRowCancelingEdit="GridView2_RowCancelingEdit"
OnRowEditing="GridView2_RowEditing"
OnRowUpdating="GridView2_RowUpdating"
OnRowDeleting="GridView2_RowDeleting"
OnRowDataBound="GridView2_RowDataBound">
<Columns>
<asp:TemplateField HeaderText="Numéro">
<ItemTemplate><asp:Label ID="lbl_ID" runat="server" Text='<%#Eval("ID") %>'></asp:Label></ItemTemplate>
<EditItemTemplate>
<table cellpadding="0" cellspacing="0" width="100%" width="100%">
<tr class="bottom" >
<td width="70px"><asp:Label ID="lbl_ID2" runat="server" Text='<%#Eval("ID") %>'></asp:Label></td>
<td width="205px"><asp:Label ID="lbl_User2" runat="server" Text='<%#Eval("User") %>'></asp:Label></td>
<td width="123px"><asp:Label ID="lbl_Dep2" runat="server" Text='<%#Eval("Departement") %>'></asp:Label></td>
<td width="52px"><asp:Label ID="lbl_Total2" runat="server" Text='<%#Eval("Total") %>'></asp:Label></td>
<td width="80px"><asp:Label ID="lbl_Date2" runat="server" Text='<%#Eval("Date") %>'></asp:Label></td>
</tr><tr class="spacer"><td></td></tr>
<tr>
<td class="support"></td>
<td colspan="4"><asp:GridView GridLines="None" CssClass="mGrid2" width="100%" ID="GridView" runat="server"></asp:GridView></td>
</tr>
<tr class="spacer">
<td></td>
</tr>
<tr>
<td colspan="2"><asp:Label ID="Lproject" runat="server" Text=""></asp:Label></td>
<td class="bottom" colspan="2" rowspan="4">
<div class="tools">
<a href="#colors_sketch" data-tool="marker">Marker</a> <a href="#colors_sketch" data-tool="eraser">Eraser</a>
</div><br />
<canvas id="colors_sketch" width="300px" height="100pxs"></canvas><asp:HiddenField ID="ImageVal" runat="server" />
</td>
<td></td>
</tr>
<tr>
<td colspan="2"><asp:Label ID="Lpaiement" runat="server" Text=""></asp:Label></td>
<td><asp:Button ID="btn_Update" runat="server" Text="Autoriser" CommandName="Update"/></td>
</tr>
<tr>
<td colspan="2">Autorisé/Refuser par :</td>
</tr>
<tr class="bottom" >
<td colspan="2"><asp:TextBox ID="Tauth" runat="server"></asp:TextBox></td>
<td><asp:Button ID="btn_Delete" runat="server" Text="Refuser" CommandName="Delete"/> </td>
</tr>
</table>
</EditItemTemplate>
</asp:TemplateField >
<asp:TemplateField HeaderText="Soumis">
<ItemTemplate><asp:Label ID="lbl_User" runat="server" Text='<%#Eval("User") %>'></asp:Label></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Departement">
<ItemTemplate> <asp:Label ID="lbl_Name" runat="server" Text='<%#Eval("Departement") %>'></asp:Label> </ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Total">
<ItemTemplate><asp:Label ID="lbl_Total" runat="server" Text='<%#Eval("Total") %>'></asp:Label></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Date">
<ItemTemplate><asp:Label ID="lbl_Date" runat="server" Text='<%#Eval("Date") %>'></asp:Label></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate><asp:Button ID="btn_Edit" runat="server" Text="↓" CommandName="Edit" /></ItemTemplate>
<EditItemTemplate>
<asp:Button ID="btn_Cancel" runat="server" Text="↑" CommandName="Cancel" />
</EditItemTemplate>
</asp:TemplateField>
</Columns>
<HeaderStyle />
</asp:GridView>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script src="https://cdn.rawgit.com/mobomo/sketch.js/master/lib/sketch.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
$('#colors_sketch').sketch();
$(".tools a").eq(0).attr("style", "color:#000");
$(".tools a").click(function () {
$(".tools a").removeAttr("style");
$(this).attr("style", "color:#000");
});
$("#btnSave").bind("click", function () {
var base64 = $('#colors_sketch')[0].toDataURL();
$('[Id*=ImageVal]').val(base64);
});
});
</script>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</asp:Content>
C#
protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowState.ToString().Contains("Edit"))
{
GridView editGrid = sender as GridView;
int colSpan = editGrid.Columns.Count;
for (int i = 1; i < colSpan - 1 ; i++)
{
e.Row.Cells[i].Visible = false;
e.Row.Cells[i].Controls.Clear();
}
e.Row.Cells[0].Attributes["ColSpan"] = (colSpan - 1).ToString();
}
}
protected void GridView2_RowEditing(object sender, System.Web.UI.WebControls.GridViewEditEventArgs e)
{
//NewEditIndex property used to determine the index of the row being edited.
GridView2.EditIndex = e.NewEditIndex;
fillcomm(Ddepfilt.SelectedValue);
GridView GV = GridView2.Rows[GridView2.EditIndex].FindControl("GridView") as GridView;
Label id = GridView2.Rows[GridView2.EditIndex].FindControl("lbl_ID2") as Label;
Label project = GridView2.Rows[GridView2.EditIndex].FindControl("Lproject") as Label;
Label paiement = GridView2.Rows[GridView2.EditIndex].FindControl("Lpaiement") as Label;
string query2 = "select bdc_projectname, bdc_paiement from BDC where bdc_num = '" + id.Text + "'";
string query = "select bdci_qty as Qty, bdci_item as Decription, bdci_price as Prix from BDCITEM inner join BDC on bdci_num = bdc_num where bdc_num = '"+id.Text+"'";
SqlDataAdapter gridadapt = new SqlDataAdapter(query, conn);
SqlDataAdapter detailsadapt = new SqlDataAdapter(query2, conn);
DataSet currentgrid = new DataSet();
DataSet details = new DataSet();
conn.Open();
gridadapt.Fill(currentgrid);
detailsadapt.Fill(details);
conn.Close();
project.Text = "Projet : " + details.Tables[0].Rows[0][0].ToString();
paiement.Text = "Méthode de paiement : " + details.Tables[0].Rows[0][1].ToString();
GV.DataSource = currentgrid;
GV.DataBind();
}
UpdatePanels 对你来说 document.ready事件只被触发一次--当页面第一次被加载时。同样的情况也适用于 window.onload.UpdatePanel，应该是静态的，只加载一次。所以，你看，为什么这是不工作。当页面第一次加载时， canvas 没有被渲染，因为我想你的GridView不是在编辑模式下。所以 document.ready-函数无法启动 canvas.
为了让这个工作，你需要启动你的 canvas 切换到edit-mode后，例如通过在server-event中添加一个启动脚本，或者通过在javascript中使用async-page-load-events。