我将查询字符串从数据库传递给我的用于图像转换的通用处理程序。 我在设计师页面上遇到以下问题
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="Image1" runat="server" ImageUrl='<%# ImageHandler.ashx?IMG_ID=Eval("Image_ID")+ &IMG_type_ID=Eval("Type_ID_FK") %>' />
</ItemTemplate>
</asp:TemplateField>
我在ImageUrl上遇到了问题。
以下是我的主要设计师代码
<form id="form1" runat="server">
<div style="width: 960px; height: 100%; padding: 0; margin: 0; font-size: 0.875em;
line-height: 1.785em;">
<div>
<asp:Panel ID="Panel1" runat="server">
<h1>
Welcome To Blue Marine! Please login with your account</h1>
<br />
<h2>
Login Area
</h2>
<div>
Username
<asp:TextBox ID="txt_username" runat="server" ControlToValidate=" txt_username"></asp:TextBox><span>*</span><asp:RequiredFieldValidator
ID="RequiredFieldValidator1" runat="server" ErrorMessage="Please Enter Valid Entry"
ControlToValidate="txt_username"></asp:RequiredFieldValidator>
<br />
Password
<asp:TextBox ID="txt_password" runat="server"></asp:TextBox><span>*</span><asp:RequiredFieldValidator
ID="RequiredFieldValidator2" runat="server" ControlToValidate="txt_password"
ErrorMessage="Please Enter Valid Entry"></asp:RequiredFieldValidator>
<br />
<div style="margin-left: 90px">
<asp:Button ID="btn_Submit" runat="server" Text="Submit" OnClick="btn_Submit_Click" />
</div>
</asp:Panel>
</div>
<div>
<asp:Panel ID="Panel2" runat="server" Visible="False">
<div style="text-align: right">
Hello!
<asp:Label ID="lb_username" runat="server" Text="Label"></asp:Label>
<br />
<div>
<asp:LinkButton ID="Linkbtn_signout" runat="server" OnClick="Linkbtn_signout_Click">SignOut</asp:LinkButton>
</div>
</div>
<div style="text-align: left">
<h1>
Image Upload Section</h1>
<p>
You can upload Images here One at a time Format Supported JPG,BMP,PNG
<br />
</p>
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
<asp:FileUpload ID="FileUpload1" runat="server" /><br />
<asp:SqlDataSource ID="SqlDataSource_ImageType" runat="server" ConnectionString="<%$ ConnectionStrings:db_string2 %>"
SelectCommand="SELECT [Type_ID_PK], [TypeName] FROM [ImageType]"></asp:SqlDataSource>
<br />
Select Image Type
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource_ImageType"
DataTextField="Type_ID_PK" DataValueField="Type_ID_PK">
</asp:DropDownList>
<span>*</span>
<asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="Select Image Type"
ControlToValidate="DropDownList1"></asp:RequiredFieldValidator>
<br />
<asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="Upload" /><br />
<br />
<asp:Label ID="lblMessage" runat="server"></asp:Label><br />
<br />
<br />
<div style="text-align: center; margin-left: 170px">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource_DbImage"
EnableModelValidation="True" AllowPaging="True" AllowSorting="True" Width="566px"
DataKeyNames="Image_ID,Type_ID_FK">
<Columns>
<asp:BoundField DataField="Image_ID" HeaderText="Image_ID" InsertVisible="False"
ReadOnly="True" SortExpression="Image_ID" />
<asp:BoundField DataField="Type_ID_FK" HeaderText="Type_ID_FK" SortExpression="Type_ID_FK"
ReadOnly="True" />
<asp:BoundField DataField="ImageName" HeaderText="ImageName" SortExpression="ImageName" />
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="Image1" runat="server" ImageUrl='<%# ImageHandler.ashx?IMG_ID=Eval("Image_ID")+ &IMG_type_ID=Eval("Type_ID_FK") %>' />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</div>
<asp:SqlDataSource ID="SqlDataSource_DbImage" runat="server" ConnectionString="<%$ ConnectionStrings:db_string2 %>"
SelectCommand="SELECT * FROM [Image_Link]"></asp:SqlDataSource>
</div>
</asp:Panel>
</div>
</div>
</form>
我的代码背后：
public partial class Admin : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (Session.Count > 0)
{
try
{
string id = Convert.ToString(Session["UserID"]);
if (id != "")
{
if (!IsPostBack)
{
Panel1.Visible = false;
Panel2.Visible = true;
}
else
{
Panel1.Visible = false;
Panel2.Visible = true;
}
}
}
catch (NullReferenceException n)
{
}
}
else
{
if (!IsPostBack)
{
Panel1.Visible = true;
}
}
}
protected void btn_Submit_Click(object sender, EventArgs e)
{
Session.Clear();
bool result = Check_User_Login(txt_username.Text, txt_password.Text);
if (result == true)
{
Panel1.Visible = false;
Panel2.Visible = true;
}
else
{
Response.Write("<script>alert('Admin Account Does not exist!');</script>");
}
}
public bool Check_User_Login(string para_name, string para_password)
{
string db_username, dp_password;
Web_Eng.DatabaseConection.comm = new SqlCommand("Select Top 1 a.Admin_ID From [Admin] a Order By a.Admin_ID Desc;", Web_Eng.DatabaseConection.connect());
int id = (int)Web_Eng.DatabaseConection.comm.ExecuteScalar();
for (int i = 1; i <= id; i++)
{
Web_Eng.DatabaseConection.comm.CommandText = "select a.Admin_Name,a.[Password] from [Admin] a where a.Admin_ID=" + i + ";";
#region use to retrieve whole row from database
Web_Eng.DatabaseConection.entrieRow_Reader = Web_Eng.DatabaseConection.comm.ExecuteReader();
while (Web_Eng.DatabaseConection.entrieRow_Reader.Read())
{
db_username = Web_Eng.DatabaseConection.entrieRow_Reader["Admin_Name"].ToString();
dp_password = Web_Eng.DatabaseConection.entrieRow_Reader["Password"].ToString();
if (db_username == para_name && dp_password == para_password)
{
Session["UserID"] = i;
lb_username.Text = db_username;
Web_Eng.DatabaseConection.entrieRow_Reader.Close();
return true;
}
}
Web_Eng.DatabaseConection.entrieRow_Reader.Close();
#endregion
}
return false;
}
protected void Linkbtn_signout_Click(object sender, EventArgs e)
{
Session.Clear();
Page.Response.Redirect("Index.aspx");
}
protected void btnUpload_Click(object sender, EventArgs e)
{
string strImageName = txtName.Text.ToString();
if (FileUpload1.PostedFile != null && FileUpload1.PostedFile.FileName != "")
{
byte[] imageSize = new byte[FileUpload1.PostedFile.ContentLength];
HttpPostedFile uploadedImage = FileUpload1.PostedFile;
uploadedImage.InputStream.Read(imageSize, 0, (int)FileUpload1.PostedFile.ContentLength);
// Create SQL Command
int id=Convert.ToInt32(DropDownList1.SelectedItem.Value);
int result = AddImage_DB(strImageName, id, imageSize);
if (result > 0)
lblMessage.Text = "File Uploaded";
GridView1.DataBind();
}
}
public int AddImage_DB(string para_imagename, int para_typeID, byte[] para_image)
{
try
{
//DatabaseConection.cmd.con;
Web_Eng.DatabaseConection.cmd.Connection = Web_Eng.DatabaseConection.connect();
Web_Eng.DatabaseConection.cmd = new SqlCommand("Insert_Image_Table", Web_Eng.DatabaseConection.connect());
Web_Eng.DatabaseConection.cmd.CommandType = CommandType.StoredProcedure;
Web_Eng.DatabaseConection.cmd.Parameters.Add(new SqlParameter("@typeID", SqlDbType.Int)).Value = para_typeID;
Web_Eng.DatabaseConection.cmd.Parameters.Add(new SqlParameter("@ImageName", SqlDbType.NVarChar)).Value = para_imagename;
Web_Eng.DatabaseConection.cmd.Parameters.Add(new SqlParameter("@convertedImage", SqlDbType.Image, para_image.Length)).Value = para_image;
Web_Eng.DatabaseConection.cmd.ExecuteNonQuery();
return 1;
}
catch (Exception er)
{
Response.Write("<script>alert('Error');</script>");
return 0;
}
}
}
我的通用处理程序
public class ImageHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
// Create SQL Command
Web_Eng.DatabaseConection.comm = new SqlCommand("Select img.ImageName,img.CompleteImage from Image_Link img where img.Image_ID=@IMG_ID and img.Type_ID_FK=@IMG_type_ID;", Web_Eng.DatabaseConection.connect());
Web_Eng.DatabaseConection.cmd.CommandType = System.Data.CommandType.Text;
// Img ID
SqlParameter ImageID = new SqlParameter("@IMG_ID", System.Data.SqlDbType.Int);
ImageID.Value = context.Request.QueryString["IMG_ID"];
// iMG Type ID
SqlParameter Image_Type_ID = new SqlParameter("@IMG_type_ID", System.Data.SqlDbType.Int);
Image_Type_ID.Value = context.Request.QueryString["IMG_type_ID"];
// Adding Parameters
Web_Eng.DatabaseConection.cmd.Parameters.Add(ImageID);
Web_Eng.DatabaseConection.cmd.Parameters.Add(Image_Type_ID);
SqlDataReader dReader = Web_Eng.DatabaseConection.cmd.ExecuteReader();
dReader.Read();
context.Response.BinaryWrite((byte[])dReader["CompleteImage"]);
dReader.Close();
}
public bool IsReusable
{
get
{
return false;
}
}
}
在将查询字符串传递给我的处理程序
时，不知道我做错了什么先谢谢
答案 0 :(得分：0)
请尝试以下语法：
<asp:Image ID="Image1" runat="server" ImageUrl='ImageHandler.ashx?IMG_ID=<%# Eval("Image_ID")+&IMG_type_ID=Eval("Type_ID_FK") %>' />
答案 1 :(得分：0)
谢谢大家，我已经解决了我自己的问题，我正在为其他可能遇到同样问题的人发布答案，这将有助于他们
只需替换
<asp:Image ID="Image1" runat="server" ImageUrl='<%# ImageHandler.ashx?IMG_ID=Eval("Image_ID")+ &IMG_type_ID=Eval("Type_ID_FK") %>' />
通过
<asp:Image ID="Image1" runat="server" ImageUrl='<%# "ImageHandler.ashx?IMG_ID=" + Eval("Image_ID")+"&IMG_type_ID="+Eval("Type_ID_FK")%>' />
答案 2 :(得分：0)
public void ProcessRequest(HttpContext context)
{
using (SqlConnection connection = new SqlConnection())
{
connection.ConnectionString = "Server=ESLHP280G1P\\SQLEXPRESS; Database=Sample; user id=sa; password=sa@123";
connection.Open();
SqlCommand cmd = new SqlCommand("tblImage_Retrieve", connection);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@id", context.Request.QueryString["id"]);
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
byte[] bytes = (byte[])dr["photo"];
if (bytes.Length > 0 && bytes != null)
{
context.Response.ContentType = "jpg";
context.Response.BinaryWrite(bytes);
}
}
}
}