我有 3 个文件上传，只允许用户选择图像。问题是，无论用户是否选择带有文件上传的图片，我都会将默认的“Images/noImage.jpg”路径保存到我的数据库中。我也相信我明白为什么。filename我将变量预设为""空字符串。这是我感到困惑的地方，如果我将filename变量设置为文件上传的值，我会收到“对象未设置为对象的实例”错误，告诉我它正在寻找一个不存在的值。这是我尝试过的：
//ImageAlt labels current Text is set to 'Images/'
string ImgPath1 = lblImageAlt1.Text.ToString();
string ImgPath2 = lblImageAlt2.Text.ToString();
string ImgPath3 = lblImageAlt3.Text.ToString();
//Get Filename from fileupload control
string filename1 = "";
string filename2 = "";
string filename3 = "";
if (fileuploadimages1.HasFile)
{
filename1 = Path.GetFileName(fileuploadimages1.PostedFile.FileName);
fileuploadimages1.SaveAs(Server.MapPath(ImgPath1 + filename1));
}
else
{
filename1 = "noImage.jpg";
}
if (fileuploadimages2.HasFile)
{
filename2 = Path.GetFileName(fileuploadimages2.PostedFile.FileName);
fileuploadimages2.SaveAs(Server.MapPath(ImgPath2 + filename2));
}
else
{
filename2 = "noImage.jpg";
}
if (fileuploadimages3.HasFile)
{
filename3 = Path.GetFileName(fileuploadimages3.PostedFile.FileName);
fileuploadimages3.SaveAs(Server.MapPath(ImgPath3 + filename3));
}
else
{
filename3 = "noImage.jpg";
}
//Save images into Images folder
fileuploadimages1.SaveAs(Server.MapPath(ImgPath1 + filename1));
fileuploadimages2.SaveAs(Server.MapPath(ImgPath2 + filename2));
fileuploadimages3.SaveAs(Server.MapPath(ImgPath3 + filename3));
//Getting SiteSqlServer2 from web.config connectionstring
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlconnection1"].ToString());
//Open the database connection
conn.Open();
//Query to insert images path and name into database
SqlCommand cmd = new SqlCommand("Insert into my_db(CreateDate,ItemName,ItemType,ImageSrc1,ImageAlt1,ImageSrc2,ImageAlt2,ImageSrc3,ImageAlt3,ItemDescription,ItemPrice,FName,LName,ContactNum,AltContactNum,IsApproved,IsExpired,Email,IsRejected) values(@CreateDate, @ItemName, @ItemType, @ImageSrc1, @ImageAlt1, @ImageSrc2, @ImageAlt2, @ImageSrc3, @ImageAlt3, @ItemDescription, @ItemPrice, @FName, @LName, @ContactNum, @AltContactNum, @IsApproved, @IsExpired, @Email, @IsRejected)", conn);
//Passing parameters to query
cmd.Parameters.AddWithValue("@CreateDate", CreateDate);
cmd.Parameters.AddWithValue("@ItemName", ItemName);
cmd.Parameters.AddWithValue("@ItemType", ItemType);
cmd.Parameters.AddWithValue("@ImageSrc1", filename1);
cmd.Parameters.AddWithValue("@ImageAlt1", ImgPath1 + filename1);
cmd.Parameters.AddWithValue("@ImageSrc2", filename2);
cmd.Parameters.AddWithValue("@ImageAlt2", ImgPath2 + filename2);
cmd.Parameters.AddWithValue("@ImageSrc3", filename3);
cmd.Parameters.AddWithValue("@ImageAlt3", ImgPath3 + filename3);
cmd.Parameters.AddWithValue("@ItemDescription", ItemDescription);
cmd.Parameters.AddWithValue("@ItemPrice", ItemPrice);
cmd.Parameters.AddWithValue("@FName", FName);
cmd.Parameters.AddWithValue("@LName", LName);
cmd.Parameters.AddWithValue("@ContactNum", ContactNum);
cmd.Parameters.AddWithValue("@AltContactNum", AltNum);
cmd.Parameters.AddWithValue("@IsApproved", isApproved);
cmd.Parameters.AddWithValue("@IsExpired", isExpired);
cmd.Parameters.AddWithValue("@Email", Email);
cmd.Parameters.AddWithValue("@IsRejected", isRejected);
cmd.ExecuteNonQuery();
//Close
conn.Close();
Response.Redirect("form.aspx");
}
如前所述，如果图像路径设置为，图像将正确上传，filename1 = Path.GetFileName(fileuploadimages1.PostedFile.FileName);....但我应该能够为不希望添加全部 3 个或仅添加 1 个或 2 个或根本不添加的用户设置例外。