c# - 将字节从 sql server 渲染到图像控件？

Question

标记:

<asp:ListView ID="lvGallery" runat="server" DataSourceID="SqlDataSource1">
    <LayoutTemplate>
        <table runat="server" id="tableGallery">
            <tr runat="server" id="itemPlaceHolder"></tr>       
        </table>       
    </LayoutTemplate>
    <ItemTemplate>       
    <tr>
        <td>
            <div class="box_img2">
                <div class="g_size">
                    <a runat="server" id="linkImage">
                        <img id="Image1" runat="server" src="MyImage.jpg" />
                    </a>
                </div>         
            </div>
        </td>
    </tr>
   </ItemTemplate>
</asp:ListView>    
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="..."  ProviderName="System.Data.SqlClient"  SelectCommand="SELECT [Image] FROM [GalleryImages]"></asp:SqlDataSource>

代码隐藏:

public void ProcessRequest(HttpContext context)
{
    //write your handler implementation here.
    string username = Convert.ToString(context.Request.QueryString["username"]);
    if (username != null)
    {
        DataSet ds = new DataSet();
        SqlDataAdapter da = new SqlDataAdapter();
        byte[] arrContent;
        DataRow dr;
        string strSql;
        strSql = "Select Image from GalleryImages where username = '" + username + "'";
        da = new SqlDataAdapter(strSql, connection.ConnectionString);
        da.Fill(ds);
        dr = ds.Tables[0].Rows[0];
        arrContent = (byte[])dr["ImageFile"];
        context.Response.ContentType = "jpeg";
        context.Response.OutputStream.Write(arrContent, 0, arrContent.Length);
        context.Response.End();
    }
}

我还在 web.config 中添加了 httphandlers 部分。但是我没有在 ListView 控件中获取图像。

Answer 1

您必须创建一个返回图像的 http 处理程序

public void ProcessRequest(HttpContext context)
{
    byte[] yourImage = //get your image byte array
    context.Response.BinaryWrite(yourImage);
    context.Request.ContentType = "image/jpeg";
    context.Response.AddHeader("Content-Type", "image/jpeg");
    context.Response.AddHeader("Content-Length", (yourImage).LongLength.ToString());
    con.Close();

    context.Response.End();
    context.Response.Close();
}

您可以通过从 visual studio 创建一个 GenericHandler 文件类型并添加前面的代码来做到这一点，然后您可以调用您可以将通用处理程序的 url 写为图像源