我在上传图片代码时遇到问题..错误是未将Object reference设置为对象的实例.

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问题描述

我的代码是，
C#代码
受保护的无效btnSubmit_Click(对象发送者，EventArgs e)
{
SqlConnection连接= null;
试试
{
FileUpload img =(FileUpload)imgUpload;
Byte [] imgByte = null;
如果(img.HasFile && img.PostedFile！= null)
{
HttpPostedFile File = imgUpload.PostedFile;
imgByte =新的Byte [File.ContentLength];
File.InputStream.Read(imgByte，0，File.ContentLength);
}
字符串conn = ConfigurationManager.ConnectionStrings ["EmployeeConnString"].ConnectionString;
connection =新的SqlConnection(conn);
connection.Open();
字符串sql ="INSERT INTO EmpDetails(empname，empimg)VALUES(@ empname，@ empimg)";
SqlCommand cmd =新的SqlCommand(sql，连接);
cmd.Parameters.AddWithValue("@ empname"，txtEName.Text.Trim());
cmd.Parameters.AddWithValue("@ empimg"，imgByte);
int id = Convert.ToInt32(cmd.ExecuteScalar());
lblResult.Text = String.Format("Employee ID is {0}"，id);
}
赶上
{
lblResult.Text =出现错误";
}
终于
{
connection.Close();
}

my code is,
C# code
protected void btnSubmit_Click(object sender, EventArgs e)
{
SqlConnection connection = null;
try
{
FileUpload img = (FileUpload)imgUpload;
Byte[] imgByte = null;
if (img.HasFile && img.PostedFile != null)
{
HttpPostedFile File = imgUpload.PostedFile;
imgByte = new Byte[File.ContentLength];
File.InputStream.Read(imgByte, 0, File.ContentLength);
}
string conn = ConfigurationManager.ConnectionStrings["EmployeeConnString"].ConnectionString;
connection = new SqlConnection(conn);
connection.Open();
string sql = "INSERT INTO EmpDetails(empname,empimg)VALUES(@empname,@empimg)";
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddWithValue("@empname", txtEName.Text.Trim());
cmd.Parameters.AddWithValue("@empimg", imgByte);
int id = Convert.ToInt32(cmd.ExecuteScalar());
lblResult.Text = String.Format("Employee ID is{0}", id);
}
catch
{
lblResult.Text = "There was an error";
}
finally
{
connection.Close();
}

推荐答案

try
{
string filepath = AppDomain.CurrentDomain.BaseDirectory + "gallery/";
<pre lang="cs">if (!Directory.Exists(filepath))
           {
               Directory.CreateDirectory(filepath);
           }
<pre lang="sql">if (FileUpload.HasFile)
        {
 tempName1 = Guid.NewGuid().ToString().Substring(0, 5);
string fileExtension = Path.GetExtension(FileUpload.FileName);
 imgupload.SaveAs(AppDomain.CurrentDomain.BaseDirectory + filepath + tempName1+fileExtension );

string conn = ConfigurationManager.ConnectionStrings["EmployeeConnString"].ConnectionString;
connection = new SqlConnection(conn);
connection.Open();
string sql = "INSERT INTO EmpDetails(empname,empimg)VALUES(@empname,@empimg)";
SqlCommand cmd = new SqlCommand(sql, connection);
cmd.Parameters.AddWithValue("@empname", txtEName.Text.Trim());
cmd.Parameters.AddWithValue("@empimg", tempName1+fileExtension);
int id = Convert.ToInt32(cmd.ExecuteScalar());
lblResult.Text = String.Format("Employee ID is{0}", id);
}
}
catch
{
//error
}

谢谢
~~ Karthik.J ~~

Thanx
~~Karthik.J~~

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CMD