Question

我有一个存储在表中的图像，以及一个用于插入，更新和删除该表中的行的gridview（Default.aspx，Default1.apsx.cs）。但是，列之一是Varbinary（Max）数据类型。为了将该blob渲染为Gridview上的图像，我编写了一个图像处理程序（ImageHandler.ashx）。如何公开gridview名称gvHoursEmp，使其包含在ImageHandler.aspx的上下文中。它们都是通用名称空间下通用项目的成员。

// Default.aspx代码段。 HandWrittenSignature是我尝试在gvHoursEmp网格视图中正确显示的Blob。

<%@ Page Language="C#" AutoEventWireup="true" 
CodeFile="Default1.aspx.cs" Inherits="HoursOfServiceGridView.Default" 
CodeBehind="Default1.aspx.cs" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Hours of Service Employee Master</title>
<link  rel="icon"
 type="image/png"   
 href="~/images/SaveRow_16x.png" />
</head>
<body>
<form id="form1" runat="server">
    <div>
        <asp:GridView ID="gvHoursEmp" runat="server" AutoGenerateColumns="False"
            DataKeyNames="ID" ShowFooter="True" ShowHeaderWhenEmpty="True" OnRowCommand="gvHoursEmp_RowCommand"
            OnRowEditing="gvHoursEmp_RowEditing"  OnRowUpdating="gvHoursEmp_RowUpdating" OnRowCancelingEdit="gvHoursEmp_RowCancelingEdit"
            OnRowDeleting="gvHoursEmp_RowDeleting" CellPadding="4" AllowSorting="True" ToolTip="True" ValidateRequestMode="Disabled" BackColor="White" BorderColor="#3366CC" BorderStyle="None" BorderWidth="1px" >
            <%--Theme Properties--%>
            <FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
            <HeaderStyle BackColor="#003399" Font-Bold="True" ForeColor="#CCCCFF" Font-Names="Arial" />
            <RowStyle ForeColor="#003399" Font-Names="Arial" BackColor="White" />
            <Columns>
                 <asp:TemplateField HeaderText="First Name" HeaderStyle-Width="10%" ItemStyle-Width="10%" FooterStyle-Width="10%">
                    <ItemTemplate>
                        <asp:Label Text='<%# Eval("FirstName")  %>' runat="server" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtFirstName" Text='<%# Eval("FirstName") %>' runat="server" />
                    </EditItemTemplate>
                    <FooterTemplate>
                        <asp:TextBox ID="txtFirstNameFooter" runat="server" />
                    </FooterTemplate>
                    <FooterStyle Width="10%" HorizontalAlign="Left" VerticalAlign="Middle"></FooterStyle>
                    <HeaderStyle Font-Names="Arial" />
                    <ItemStyle Width="10%" Height="10%"></ItemStyle>
                    </asp:TemplateField>
                <asp:TemplateField HeaderText="Mid Init">
                    <ItemTemplate>
                        <asp:Label Text='<%# Eval("MiddleInitial")  %>' runat="server" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtMiddleInitial" Text='<%# Eval("MiddleInitial") %>' runat="server" />
                    </EditItemTemplate>
                    <FooterTemplate>
                        <asp:TextBox ID="txtMiddleInitialFooter" runat="server" />
                    </FooterTemplate>
                    <ControlStyle Height="10%" Width="20px" />
                    <FooterStyle Height="10%" Width="20px" Wrap="False" HorizontalAlign="Left" VerticalAlign="Middle" />
                    <HeaderStyle Font-Names="Arial" Height="10%" Width="20px" HorizontalAlign="Left" />
                    <ItemStyle Height="10%" Width="20px" Font-Names="Arial" HorizontalAlign="Left" VerticalAlign="Middle" />
                </asp:TemplateField>
                <asp:TemplateField HeaderText="Last Name">
                    <ItemTemplate>
                        <asp:Label Text='<%# Eval("LastName")  %>' runat="server" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtLastName" Text='<%# Eval("LastName") %>' runat="server" />
                    </EditItemTemplate>
                    <FooterTemplate>
                        <asp:TextBox ID="txtLastNameFooter" runat="server" />
                    </FooterTemplate>
                    <ControlStyle Height="10%" Width="125px" />
                    <FooterStyle Height="10%" Width="10%" />
                    <HeaderStyle Font-Names="Arial" Height="10%" Width="10%" />
                    <ItemStyle Height="10%" Width="125px" />
                </asp:TemplateField>           
                 <asp:TemplateField HeaderText="Employee ID">
                    <ItemTemplate>
                        <asp:Label Text='<%# Eval("EmployeeID")  %>' runat="server" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="txtEmployeeID" Text='<%# Eval("EmployeeID") %>' runat="server" />
                    </EditItemTemplate>
                    <FooterTemplate>
                        <asp:TextBox ID="txtEmployeeIDFooter" runat="server" />
                    </FooterTemplate>
                </asp:TemplateField>
                 <asp:TemplateField HeaderText="Signature">
                     <ItemStyle HorizontalAlign="Center" Height="100px" Width="100px" Wrap="False" />
                     <ItemTemplate>
                       <asp:Image  ID="Image1" runat="server" ImageUrl='<%# "ImageHandler.ashx?ID=1"+ Eval("HandWrittenSignature") %>' /> 
                      </ItemTemplate>
                      <EditItemTemplate>
                        <asp:TextBox ID="txtSignature" Text='<%# Eval("HandWrittenSignature") %>' runat="server" />
                    </EditItemTemplate>
                 </asp:TemplateField>

ImageHandler.ashx代码在这里：

<%@ WebHandler Language="C#" Class="ImageHandler"   %>
using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI.WebControls;

namespace HoursOfServiceGridView
{
public class ImageHandler : IHttpHandler

{
    public bool IsReusable { get { return true; } }
    public void ProcessRequest(HttpContext context)
    {
        string id = context.Request.QueryString["id"];
        SqlConnection sqlCon = new SqlConnection(@"Data Source=365-ETDB- 
01A;Initial Catalog=TMDS_ODS;Integrated Security=True");
        SqlCommand sqlCmd = new SqlCommand("SELECT HandWrittenSignature 
FROM dbo.HoursOfServiceEmployee WHERE EmployeeID = @EmployeeID", 
sqlCon);
        sqlCmd.CommandType = CommandType.Text; SqlCmd.Parameters.AddWithValue("@EmployeeID",Convert.ToInt32(gvHoursEmp.Rows[e.RowIndex].FindControl("txtEmployeeID") as TextBox).Text.Trim());
        sqlCon.Open();
        byte[] pict = (byte[])sqlCmd.ExecuteScalar();
        sqlCon.Close();

        context.Response.ContentType = "image/bmp";
        context.Response.OutputStream.Write(pict, 78, pict.Length - 78);

    }


    }
}

由于Gridview在ImageHandler.aspx页面的当前上下文之外，因此Gridview无法显示HandWrittenSignature Blob的图像。

如何在项目中的另一个页面上共享一个普通的Gridview？

0 个答案: