ASP.NET更新面板不能在Web用户控件内工作

Question

我已经创建了一个html5画布和javascript签名板，我希望作为具有更新面板的Web用户控件来处理按钮点击。出于某种原因，如果我将更新面板和签名板控件直接添加到aspx文件中，则自动回发事件可以正常工作，但是当我将相同的代码放入Web用户控件时，会出现字段（画布，按钮，div等）回发不再有效。在这两种情况下，我都将我的脚本管理器放在更新面板上方。

这里是我的ascx代码：

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="Signature_Pad.ascx.cs"  Inherits="Controls_Signature_Pad" %> 

<asp:UpdatePanel runat="server" ID="signatureUpdate" updatemode="Conditional"> 
    <Triggers> 
    <asp:AsyncPostBackTrigger controlid="signatureApprove" eventname="Click" /> 
    <asp:AsyncPostBackTrigger controlid="sigClear" eventname="Click" /> 
    <asp:AsyncPostBackTrigger controlid="sigCancel" eventname="Click" /> 
    </Triggers> 
    <ContentTemplate> 
     <fieldset id="SignatureFieldSet" runat="server" style=" border: 1 solid black;"> 
     <p><asp:Label ID="signatureTextLabel" AutoPostBack="true" runat="server" Text=""></asp:Label></p> 
     <div id="canvasDiv" style="height: 300px; border:0px solid #000000; "> 
      <canvas id="canvasSignature" style="border:1px solid #000000;"></canvas> 
     </div> 
     <div id="sigButtonDiv" style=" border:0px solid #000000;"> 
      <br /><br /> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="OnApprove" ID="signatureApprove" Text="Approve" /> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="OnClear" ID="sigClear" Text="Clear" /> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="OnCancel" ID="sigCancel" Text="Cancel" /> 
     </div> 
    </fieldset> 
</ContentTemplate> 
</asp:UpdatePanel> 

这里是背着我的ascx代码：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 

public partial class Controls_Signature_Pad : System.Web.UI.UserControl 
{ 
private string signatureData; 
private string signatureText; 

public string SignatureData 
{ 
    get { return signatureData; } 
    set { signatureData = value; } 
} 
public string SignatureText 
{ 
    get { return signatureText; } 
    set { signatureText = value; } 
} 

public void OnApprove(object sender, EventArgs e) 
{ 
    UtilityClass.showMessageBox("Approve Clicked", this); 
    SignatureText = "Approved Clicked"; 
} 
public void OnClear(object sender, EventArgs e) 
{ 
    UtilityClass.showMessageBox("Clear Clicked", this); 
    SignatureText = "Clear Clicked"; 
} 
public void OnCancel(object sender, EventArgs e) 
{ 
    UtilityClass.showMessageBox("Cancel Clicked", this); 
    SignatureText = "Cancel Clicked"; 
} 

public void Page_Load(object sender, EventArgs e) 
{ 
    signatureTextLabel.Text = signatureText; 
} 
} 

这里是我的相关的aspx：

... 
<%@ Register TagPrefix="mjt" TagName="SignaturePad" Src="~/Controls/Signature_Pad.ascx" %> 
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server"> 
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server"> 

<asp:ScriptManager ID="ScriptManager" runat="server" EnablePartialRendering="true" EnablePageMethods="true"></asp:ScriptManager> 
<mjt:SignaturePad ID="SignaturePad" runat="server" Visible="true" SignatureData="" SignatureText="Test Signature Test." /> 

... 

Answer 1

在代码中添加事件处理后面固定的问题。这是我的代码：

该控件有三个触发事件所需的按钮（批准，清除和取消）。

在ascx.cs：

public event EventHandler Approved; 
public event EventHandler Cleared; 
public event EventHandler Canceled; 

protected void signatureApprove_clicked(object sender, EventArgs e) 
{ 

    if(Approved != null) 
    Approved(this, EventArgs.Empty); 

} 
protected void sigClear_clicked(object sender, EventArgs e) 
{ 
     if (Cleared != null) 
     Cleared(this, EventArgs.Empty); 
} 
protected void sigCancel_clicked(object sender, EventArgs e) 
{ 
     if (Canceled != null) 
     Canceled(this, EventArgs.Empty); 
} 

在ASCX：

<asp:UpdatePanel runat="server" ID="signatureUpdate" updatemode="Conditional"> 
    <Triggers> 
    <asp:AsyncPostBackTrigger controlid="signatureApprove" eventname="Click" /> 
    <asp:AsyncPostBackTrigger controlid="sigClear" eventname="Click" /> 
    <asp:AsyncPostBackTrigger controlid="sigCancel" eventname="Click" /> 
    </Triggers> 
    <ContentTemplate> 
     <fieldset id="SignatureFieldSet" class="fieldSetStyle" > 
     <p><asp:Label ID="signatureTextLabel" AutoPostBack="true" runat="server" Text=""></asp:Label></p> 
     <div id="canvasDiv" runat="server" > 
      <canvas id="canvasSignature" class="canvasStyle"></canvas> 
     </div> 
     <div id="sigButtonDiv"> 
     <br /> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="signatureApprove_clicked" ID="signatureApprove" Text="Approve" CssClass="buttonStyle" /> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="sigClear_clicked" ID="sigClear" Text="Clear" CssClass="buttonStyle"/> 
      <asp:Button AutoPostBack="true" runat="server" OnClick="sigCancel_clicked" ID="sigCancel" Text="Cancel" CssClass="buttonStyle"/> 
     </div> 
     </fieldset> 
    </ContentTemplate> 
</asp:UpdatePanel> 

在ASPX：

<mjt:SignaturePad OnApproved="Signature_Approved" OnCanceled="Signature_Canceled" OnCleared="Signature_Cleared" ID="SignaturePad" runat="server" /> 

在aspx.cs：

protected void Signature_Approved(object sender, EventArgs e) 
{ 
    //Do signature approved action 
} 
protected void Signature_Canceled(object sender, EventArgs e) 
{ 
    //Do signature cancel action 
} 
protected void Signature_Cleared(object sender, EventArgs e) 
{ 
    //Do signature cleared action 
}