我添加了编辑按钮列,然后写了UpdateCommand事件,编译通过,可是执行的时候就出现下面的错误:对象必须实现 IConvertible。
说明: 执行当前 Web 请求期间,出现未处理的异常。请检查堆栈跟踪信息,以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.InvalidCastException: 对象必须实现 IConvertible。事件代码如下,请各位前辈帮忙指点一下,谢谢private void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
this.conn.Open();
string sql="update Employees set LastName=@LastName,FirstName=@FirstName,Title=@Title,Address=@Address,City=@City,Region=@Region,Country=@Country,HomePhone=@HomePhone where EmployeeID=@EmployeeID";
SqlCommand cmd=new SqlCommand(sql,this.conn);
string eid;
eid=this.DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();
cmd.Parameters.Add(new SqlParameter("@LastName",SqlDbType.NVarChar,20));
cmd.Parameters.Add(new SqlParameter("@FirstName",SqlDbType.NVarChar,10));
cmd.Parameters.Add(new SqlParameter("@Title",SqlDbType.NVarChar,30));
cmd.Parameters.Add(new SqlParameter("@Address",SqlDbType.NVarChar,60));
cmd.Parameters.Add(new SqlParameter("@City",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Region",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Country",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@HomePhone",SqlDbType.NVarChar,24)); TextBox txtLastName=(TextBox)e.Item.Cells[1].Controls[0];
TextBox txtFirstName=(TextBox)e.Item.Cells[2].Controls[0];
TextBox txtTitle=(TextBox)e.Item.Cells[3].Controls[0];
TextBox txtAdress=(TextBox)e.Item.Cells[4].Controls[0];
TextBox txtCity=(TextBox)e.Item.Cells[5].Controls[0];
TextBox txtRegion=(TextBox)e.Item.Cells[6].Controls[0];
TextBox txtCountry=(TextBox)e.Item.Cells[7].Controls[0];
TextBox txtHomePhone=(TextBox)e.Item.Cells[8].Controls[0]; //cmd.Parameters["@EmployeeID"].Value=EmployeeID;
cmd.Parameters["@LastName"].Value=txtLastName.Text;
cmd.Parameters["@FirstName"].Value=txtFirstName.Text;
cmd.Parameters["@Title"].Value=txtTitle.Text;
cmd.Parameters["@Address"].Value=txtAdress;
cmd.Parameters["@City"].Value=txtCity.Text;
cmd.Parameters["@Region"].Value=txtRegion.Text;
cmd.Parameters["@Country"].Value=txtCountry.Text;
cmd.Parameters["@HomePhone"].Value=txtHomePhone.Text;
//
// try
// {
cmd.ExecuteNonQuery();
// }
// catch(Exception error)
// {
//
// }
// finally
// {
this.conn.Close();
this.DataGrid1.EditItemIndex=-1;
databind();
// }
说明: 执行当前 Web 请求期间,出现未处理的异常。请检查堆栈跟踪信息,以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.InvalidCastException: 对象必须实现 IConvertible。事件代码如下,请各位前辈帮忙指点一下,谢谢private void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
this.conn.Open();
string sql="update Employees set LastName=@LastName,FirstName=@FirstName,Title=@Title,Address=@Address,City=@City,Region=@Region,Country=@Country,HomePhone=@HomePhone where EmployeeID=@EmployeeID";
SqlCommand cmd=new SqlCommand(sql,this.conn);
string eid;
eid=this.DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();
cmd.Parameters.Add(new SqlParameter("@LastName",SqlDbType.NVarChar,20));
cmd.Parameters.Add(new SqlParameter("@FirstName",SqlDbType.NVarChar,10));
cmd.Parameters.Add(new SqlParameter("@Title",SqlDbType.NVarChar,30));
cmd.Parameters.Add(new SqlParameter("@Address",SqlDbType.NVarChar,60));
cmd.Parameters.Add(new SqlParameter("@City",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Region",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Country",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@HomePhone",SqlDbType.NVarChar,24)); TextBox txtLastName=(TextBox)e.Item.Cells[1].Controls[0];
TextBox txtFirstName=(TextBox)e.Item.Cells[2].Controls[0];
TextBox txtTitle=(TextBox)e.Item.Cells[3].Controls[0];
TextBox txtAdress=(TextBox)e.Item.Cells[4].Controls[0];
TextBox txtCity=(TextBox)e.Item.Cells[5].Controls[0];
TextBox txtRegion=(TextBox)e.Item.Cells[6].Controls[0];
TextBox txtCountry=(TextBox)e.Item.Cells[7].Controls[0];
TextBox txtHomePhone=(TextBox)e.Item.Cells[8].Controls[0]; //cmd.Parameters["@EmployeeID"].Value=EmployeeID;
cmd.Parameters["@LastName"].Value=txtLastName.Text;
cmd.Parameters["@FirstName"].Value=txtFirstName.Text;
cmd.Parameters["@Title"].Value=txtTitle.Text;
cmd.Parameters["@Address"].Value=txtAdress;
cmd.Parameters["@City"].Value=txtCity.Text;
cmd.Parameters["@Region"].Value=txtRegion.Text;
cmd.Parameters["@Country"].Value=txtCountry.Text;
cmd.Parameters["@HomePhone"].Value=txtHomePhone.Text;
//
// try
// {
cmd.ExecuteNonQuery();
// }
// catch(Exception error)
// {
//
// }
// finally
// {
this.conn.Close();
this.DataGrid1.EditItemIndex=-1;
databind();
// }
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TextBox txtFirstName=(TextBox)e.Item.Cells[2].Controls[0];
TextBox txtTitle=(TextBox)e.Item.Cells[3].Controls[0];
TextBox txtAdress=(TextBox)e.Item.Cells[4].Controls[0];
TextBox txtCity=(TextBox)e.Item.Cells[5].Controls[0];
TextBox txtRegion=(TextBox)e.Item.Cells[6].Controls[0];
TextBox txtCountry=(TextBox)e.Item.Cells[7].Controls[0];
TextBox txtHomePhone=(TextBox)e.Item.Cells[8].Controls[0];可能在这个地方出现问题
不知道你为什么要这样用
难道你在编辑的时候动态生成TextBox 就算你想这样,语句也不对啊。
你的页面上应该已经有文本框了吧。直接把值往里面丢不就可以了么。
this.txtLastName.Text = e.Item.Cells[1].Text;
HTML的代码:
<form id="Form1" method="post" runat="server">
<h2 id="H21">实现DataGrid控件中的编辑更新</h2>
<asp:DataGrid id="dgEdit" runat="server" BorderColor="#3366CC" BorderStyle="None" BorderWidth="1px"
BackColor="White" CellPadding="4" AutoGenerateColumns="False" DataKeyField="EmployeeID" Width="320px">
<SelectedItemStyle Font-Bold="True" ForeColor="#CCFF99" BackColor="#009999"></SelectedItemStyle>
<ItemStyle ForeColor="#003399" BackColor="White"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCCCFF" BackColor="#003399"></HeaderStyle>
<FooterStyle ForeColor="#003399" BackColor="#99CCCC"></FooterStyle>
<Columns>
<asp:TemplateColumn HeaderText="LastName">
<ItemTemplate>
<asp:Label runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.LastName") %>' ID="Label1" NAME="Label1">
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="FirstName">
<ItemTemplate>
<asp:Label runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.FirstName") %>' ID="Label2" NAME="Label2">
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="City">
<ItemTemplate>
<asp:Label runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.City") %>' ID="Label3" NAME="Label3">
</asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox runat="server" ID="txtCity" Text='<%# DataBinder.Eval(Container, "DataItem.City") %>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateColumn>
<asp:EditCommandColumn ButtonType="LinkButton" UpdateText="<img src=../../images/save.gif border=0 alt='保存'/>"
CancelText="<img src=../../images/cancel.gif border=0 alt='取消'/>" EditText="<img src=../../images/edit.gif border=0 alt='编辑'/>"></asp:EditCommandColumn>
</Columns>
<PagerStyle HorizontalAlign="Left" ForeColor="#003399" BackColor="#99CCCC" Mode="NumericPages"></PagerStyle>
</asp:DataGrid>
</form>
后台代码:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Configuration;
namespace CommonFunction.数据绑定控件
{
/// <summary>
/// DataGridEdit 的摘要说明。
/// </summary>
public class DataGridEdit : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DataGrid dgEdit; private void Page_Load(object sender, System.EventArgs e)
{
//页面初试化时进行数据绑定
if(!IsPostBack)
DataGridDataBind();
}
private void DataGridDataBind()
{
//定义数据连接对象,其中数据库连接字符串是在Web.Config文件中定义的
SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionSqlServer"].ToString());
//创建数据适配器对象
SqlDataAdapter da = new SqlDataAdapter("select top 5 EmployeeID,LastName,FirstName,City from Employees",conn);
//创建DataSet对象
DataSet ds = new DataSet();
try
{
//填充数据集
da.Fill(ds,"testTable");
//进行数据绑定
dgEdit.DataSource = ds.Tables["testTable"];
dgEdit.DataBind();
}
catch(Exception error)
{
//输出异常信息
Response.Write(error.ToString());
}
} #region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.dgEdit.CancelCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgEdit_CancelCommand);
this.dgEdit.EditCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgEdit_EditCommand);
this.dgEdit.UpdateCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgEdit_UpdateCommand);
this.Load += new System.EventHandler(this.Page_Load); }
#endregion private void dgEdit_CancelCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
//设置DataGrid控件的编辑项的索引为-1,既取消编辑
dgEdit.EditItemIndex = -1;
//数据绑定
DataGridDataBind();
} private void dgEdit_EditCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
//设置DataGrid控件的编辑项的索引为选择的当前项
dgEdit.EditItemIndex = e.Item.ItemIndex;
//数据绑定
DataGridDataBind();
} private void dgEdit_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
//取得编辑行的关键字段的值
int empID = (int)dgEdit.DataKeys[e.Item.ItemIndex];
//取得文本框中输入的内容
TextBox newCity = (TextBox)e.Item.FindControl("txtCity");
//定义SQL语句
string sqlCom = "update Employees set City='" + newCity.Text + "' where EmployeeID="+empID.ToString();
//定义数据连接对象,其中数据库连接字符串是在Web.Config文件中定义的
SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionSqlServer"].ToString());
//定义命令对象
SqlCommand cmd = new SqlCommand(sqlCom,conn);
//打开数据连接
conn.Open();
try
{
//执行SQL命令
cmd.ExecuteNonQuery();
//取消编辑
dgEdit.EditItemIndex = -1;
DataGridDataBind();
}
catch(Exception err)
{
//输出异常信息
Response.Write(err.ToString());
}
finally
{
//关闭连接对象
conn.Close();
}
}
}
}
{
this.conn.Open();
string sql="update Employees set LastName=@LastName,FirstName=@FirstName,Title=@Title,Address=@Address,City=@City,Region=@Region,Country=@Country,HomePhone=@HomePhone where EmployeeID=@EmployeeID";
SqlCommand cmd=new SqlCommand(sql,this.conn);
string eid;
eid=this.DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();
cmd.Parameters.Add(new SqlParameter("@LastName",SqlDbType.NVarChar,20));
cmd.Parameters.Add(new SqlParameter("@FirstName",SqlDbType.NVarChar,10));
cmd.Parameters.Add(new SqlParameter("@Title",SqlDbType.NVarChar,30));
cmd.Parameters.Add(new SqlParameter("@Address",SqlDbType.NVarChar,60));
cmd.Parameters.Add(new SqlParameter("@City",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Region",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@Country",SqlDbType.NVarChar,15));
cmd.Parameters.Add(new SqlParameter("@HomePhone",SqlDbType.NVarChar,24));
cmd.Parameters.Add(new SqlParameter("@EmployeeID",SqlDbType.NVarChar)); TextBox txtLastName=(TextBox)e.Item.Cells[1].Controls[0];
TextBox txtFirstName=(TextBox)e.Item.Cells[2].Controls[0];
TextBox txtTitle=(TextBox)e.Item.Cells[3].Controls[0];
TextBox txtAdress=(TextBox)e.Item.Cells[4].Controls[0];
TextBox txtCity=(TextBox)e.Item.Cells[5].Controls[0];
TextBox txtRegion=(TextBox)e.Item.Cells[6].Controls[0];
TextBox txtCountry=(TextBox)e.Item.Cells[7].Controls[0];
TextBox txtHomePhone=(TextBox)e.Item.Cells[8].Controls[0]; cmd.Parameters["@EmployeeID"].Value=eid;
cmd.Parameters["@LastName"].Value=txtLastName.Text;
cmd.Parameters["@FirstName"].Value=txtFirstName.Text;
cmd.Parameters["@Title"].Value=txtTitle.Text;
cmd.Parameters["@Address"].Value=txtAdress.Text;
cmd.Parameters["@City"].Value=txtCity.Text;
cmd.Parameters["@Region"].Value=txtRegion.Text;
cmd.Parameters["@Country"].Value=txtCountry.Text;
cmd.Parameters["@HomePhone"].Value=txtHomePhone.Text;
try
{
cmd.ExecuteNonQuery();
}
catch(Exception error)
{
}
finally
{
this.conn.Close();
this.DataGrid1.EditItemIndex=-1;
databind();
}
} }