如何在 asp.net 应用程序中实现编辑功能？

Question

以下 2 个链接提供了我的示例应用程序的预览。

http://img812.imageshack.us/i/image1adl.jpg/ ：显示我的示例应用程序。所有字段都是不言自明的（如果查询，请告诉我）

http://img834.imageshack.us/i/image2vc.jpg/ ：显示，当单击网格中的“编辑”按钮时，时间显示正确，但顺序受到干扰。 （看到 7:00 出现在顶部，然后看到时间列表）。

我的问题

1. 如何纠正计时问题？ （链接 #2）

“编辑”代码如下

protected void lnkEdit_Click(object sender, EventArgs e)
{
    int imageid = Convert.ToInt16((sender as Button).CommandArgument);

    DataSet ds = new DataSet();

    SqlConnection sqlconn = new SqlConnection();
    sqlconn.ConnectionString = ConfigurationManager.ConnectionStrings["TestConn"].ConnectionString;
    string sql = @"SELECT * FROM Images WHERE IsDeleted=0 and Imageid='"+ imageid +"'";

    SqlCommand sqlcommand = new SqlCommand(sql, sqlconn);
    sqlcommand.CommandType = CommandType.Text;
    sqlcommand.CommandText = sql;

    SqlDataAdapter da = new SqlDataAdapter(sqlcommand);
    da.Fill(ds);

    if (ds.Tables[0].Rows.Count > 0)
    {
        txtImageName.Text = ds.Tables[0].Rows[0].ItemArray[1].ToString();
        chkIsActive.Checked = Convert.ToBoolean(ds.Tables[0].Rows[0]["IsActive"].ToString());
        ddlStartTime.DataSource = ds;
        ddlStartTime.DataTextField = ds.Tables[0].Columns["StartTime"].ColumnName.ToString();
        ddlStartTime.DataValueField = ds.Tables[0].Columns["ImageId"].ColumnName.ToString();
        ddlStartTime.DataBind();
        ddlEndTime.DataSource = ds;
        ddlEndTime.DataTextField = ds.Tables[0].Columns["EndTime"].ColumnName.ToString();
        ddlEndTime.DataValueField = ds.Tables[0].Columns["ImageId"].ColumnName.ToString();
        ddlEndTime.DataBind();
        BindDropDownList();
        IsEdit = true;
    }

1. 当我在网格中编辑现有记录时，我得到了值，但记录没有被更新，而是作为新记录添加到数据库中。我知道我想写更新脚本。但是在哪里写呢？

下面的代码是一样的；

protected void btnSubmit_Click(object sender, EventArgs e)
{
    if (Page.IsPostBack)
    {
        try
        {
            string strImageName = txtImageName.Text.ToString();
            int IsActive = 1;
            if (chkIsActive.Checked)
                IsActive = 1;
            else
                IsActive = 0;

            string startDate = ddlStartTime.SelectedItem.Text;
            string endDate = ddlEndTime.SelectedItem.Text;

            if ( Convert.ToDateTime(endDate) - Convert.ToDateTime(startDate) > new TimeSpan(2, 0, 0) || Convert.ToDateTime(endDate)- Convert.ToDateTime(startDate) < new TimeSpan(2,0,0))
            {   
                //Response.Write(@"<script language='javascript'> alert('Difference between Start Time and End Time is 2 hours'); </script> ");
                lblHours.Visible = true;
                lblHours.Text = "Difference between Start Time and End Time should be 2 hours";
                return;
            }

            if (checkConflictTime())
            {
                lblMessage.Visible = true;
                lblMessage.Text = "Time Conflict";
                return;
            }

            //if (checkTimeBetween())
            //{
            //}

            if (fuFileUpload.PostedFile != null && fuFileUpload.PostedFile.FileName != "")
            {
                lblHours.Visible = false;
                byte[] imageSize = new Byte[fuFileUpload.PostedFile.ContentLength];
                HttpPostedFile uploadedImage = fuFileUpload.PostedFile;
                uploadedImage.InputStream.Read(imageSize, 0, (int)fuFileUpload.PostedFile.ContentLength);

                SqlConnection sqlconn = new SqlConnection();
                sqlconn.ConnectionString = ConfigurationManager.ConnectionStrings["TestConn"].ConnectionString;

                SqlCommand cmd = new SqlCommand();
                if (IsEdit == false)
                {
                    cmd.CommandText = "Insert into Images(FileName,FileContent,IsDeleted,IsActive,StartTime,EndTime) values (@img_name, @img_content,@IsDeleted,@IsActive,@StartTime,@EndTime)";
                }
                else
                {
                    cmd.CommandText = "Update Images set FileName=@img_name, FileContent=@img_content, IsDeleted= @IsDeleted,IsActive= @IsActive, StartTime=@StartTime,EndTime=@EndTime";
                }
                cmd.CommandType = CommandType.Text;
                cmd.Connection = sqlconn;

                SqlParameter ImageName = new SqlParameter("@img_name", SqlDbType.NVarChar, 50);
                ImageName.Value = strImageName.ToString();
                cmd.Parameters.Add(ImageName);

                SqlParameter ActualImage = new SqlParameter("@img_content", SqlDbType.VarBinary);
                ActualImage.Value = imageSize;
                cmd.Parameters.Add(ActualImage);

                SqlParameter DeletedImage = new SqlParameter("@IsDeleted", SqlDbType.Bit);
                DeletedImage.Value = 0;
                cmd.Parameters.Add(DeletedImage);

                SqlParameter IsActiveCheck = new SqlParameter("@IsActive", SqlDbType.Bit);
                IsActiveCheck.Value = IsActive;
                cmd.Parameters.Add(IsActiveCheck);

                SqlParameter StartDate = new SqlParameter("@StartTime", SqlDbType.NVarChar, 100);
                StartDate.Value = startDate;
                cmd.Parameters.Add(StartDate);

                SqlParameter EndDate = new SqlParameter("@EndTime", SqlDbType.NVarChar, 100);
                EndDate.Value = endDate;
                cmd.Parameters.Add(EndDate);

                sqlconn.Open();
                int result = cmd.ExecuteNonQuery();
                sqlconn.Close();

                if (result > 0)
                {
                    lblMessage.Visible = true;
                    lblMessage.Text = "File Uploaded!";
                    gvImages.DataBind();
                }
            }
        }
        catch (Exception ex)
        {
            lblMessage.Text = ex.ToString();
        }
    }

}

请帮忙！

Answer 1

你在哪里定义Bool/Bolean IsEdit？我认为它的值在页面回发时被重置，这就是为什么它总是 false 并且正在插入记录。我建议您使用隐藏字段来跟踪它并在那里设置它的值并在插入/更新时检查该值。最后会是这样的......

if (ds.Tables[0].Rows.Count > 0)
{
   //your code
   hiddenField.Value = "true"; // you can set default value to false
}

然后

if (hiddenField.Value == "false")
   {
    cmd.CommandText = "Insert into Images(FileName,FileContent,IsDeleted,IsActive,StartTime,EndTime) values (@img_name, @img_content,@IsDeleted,@IsActive,@StartTime,@EndTime)";
   }
   else
   {
    cmd.CommandText = "Update Images set FileName=@img_name, FileContent=@img_content, IsDeleted= @IsDeleted,IsActive= @IsActive, StartTime=@StartTime,EndTime=@EndTime";
   }