gridview动态templte字段问题 [英] gridview dynamic templte field problem
本文介绍了gridview动态templte字段问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
Hello Every One，
i我正在开发一个网站，其中列是动态的模板字段。
我的问题是在回发时我的gridview变成空白。 />
pl帮我解决这个问题。
这里是代码
Hello Every One,
i am developing one web site in that columns are dynamic by the templates fields.
my problem is on postback my gridview become blank.
pl help me to resolve this.
here is code
<pre lang="xml"><%@ Page Title="" Language="C#" MasterPageFile="~/HOSPITAL/MasterHospital.master"
AutoEventWireup="true" CodeFile="ImeiDetails.aspx.cs" Inherits="HOSPITAL_ImeiDetails"
Theme="SkinFile" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
<style type="text/css">
.style1
{
width: 100%;
}
</style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
<div>
<p class="infopost">
Imei Details
</p>
<div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<div>
<table class="style1">
<tr>
<td class="leftcol">
Select Type
</td>
<td class="leftmidd">
:
</td>
<td>
<asp:DropDownList ID="DropDownList1" runat="server">
<asp:ListItem Value="nDoctorLimit">Doctors</asp:ListItem>
<asp:ListItem Value="nChemistLimit">Chemist</asp:ListItem>
<asp:ListItem>Lab</asp:ListItem>
</asp:DropDownList>
</td>
<td>
<asp:Button ID="BtnLoadClick" runat="server" Text="Load" OnClick="BtnLoadClick_Click" />
</td>
<td>
<asp:Button ID="BtnUpdate" runat="server" Text="Update"
onclick="BtnUpdate_Click" />
</td>
<td>
<asp:UpdateProgress ID="UpdateProgress" runat="server" AssociatedUpdatePanelID="UpdatePanel1"
DisplayAfter="0" DynamicLayout="false">
<ProgressTemplate>
Pl Wait ...
<asp:Image ID="Image1" runat="server" Height="10px"
ImageUrl="~/images/progress.gif" Width="100px" />
</ProgressTemplate>
</asp:UpdateProgress>
</td>
</tr>
</table>
</div>
<div>
<asp:Panel ID="Panel2" runat="server">
</asp:Panel>
</div>
<div>
<asp:Panel ID="Panel1" runat="server" Height="500px" ScrollBars="Both"
Width="700px">
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" EmptyDataText="No Data Available">
</asp:GridView>
</asp:Panel>
</div>
<div>
</div>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</div>
</asp:Content>
C＃代码
C# Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
public partial class HOSPITAL_ImeiDetails : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
string Field;
string JoinCondition; string tablename; string RecurringField;
protected void BtnLoadClick_Click(object sender, EventArgs e)
{
if (true)
{
}
DataSet DsLimit = ClassHospital.GetDataSet("select nImeiNoLimit from hospitalmaster where nhospitalid=" + Session["Hospital_Id"].ToString());
if (DsLimit.Tables[0].Rows.Count > 0)
{
double Limit = Convert.ToDouble(DsLimit.Tables[0].Rows[0][0].ToString());
if (DropDownList1.SelectedIndex == 0)
{
tablename = "DoctorMaster";
Field = " DoctorMaster.nDoctorId as [Doctor_Id],DoctorMaster.cDoctorName AS [Doctor_Name],ImeiDetails.cImeiNo as [Imei],";
JoinCondition = " ON DoctorMaster.nHospitalId = HospitalMaster.nHospitalId LEFT OUTER JOIN " +
" ImeiDetails ON DoctorMaster.nDoctorId = ImeiDetails.nDoctorId ";
RecurringField = "nDoctorId";
}
else if (DropDownList1.SelectedIndex == 1)
{
tablename = "ChemistMaster";
Field = " ChemistMaster.nChemistId as [Chemist_Id],ChemistMaster.cChemistName AS [Chemist_Name],ImeiDetails.cImeiNo as [Imei],";
JoinCondition = " ON ChemistMaster.nHospitalId = HospitalMaster.nHospitalId LEFT OUTER JOIN " +
" ImeiDetails ON ChemistMaster.nChemistId = ImeiDetails.nChemistId ";
RecurringField = "nChemistId";
}
else if (DropDownList1.SelectedIndex == 2)
{
tablename = "LabMaster";
Field = " LabMaster.nLabId as [Lab_Id],LabMaster.cLabName AS [Lab_Name],ImeiDetails.cImeiNo as [Imei],";
JoinCondition = " ON LabMaster.nHospitalId = HospitalMaster.nHospitalId LEFT OUTER JOIN " +
" ImeiDetails ON LabMaster.nLabId = ImeiDetails.nLabId ";
RecurringField = "nLabId";
}
if (Limit != 0)
{
DataLimit(tablename, Field, JoinCondition, Limit, RecurringField);
}
}
}
public void DataLimit(string TableName, string InitialField, String InitialJoinCondition, double Limit, string RecurringJoinField)
{
if (Limit != 0)
{
for (int i = 1; i < Limit; i++)
{
InitialField += " ImeiDetails_" + i.ToString() + ".cImeiNo as [Imei_" + i.ToString() + "],";
InitialJoinCondition += " LEFT OUTER JOIN ImeiDetails AS ImeiDetails_" + i.ToString() + " ON " + TableName + "." + RecurringField + " = ImeiDetails_" + i.ToString() + "." + RecurringField+ " ";
}
}
if (InitialField.EndsWith(","))
{
InitialField = InitialField.Remove(InitialField.Length - 1, 1);
}
string FinalQuery = "SELECT " + InitialField + " FROM " + TableName + " INNER JOIN " +
" HospitalMaster " + InitialJoinCondition + " where " + TableName + ".nHospitalId=" + Session["Hospital_Id"].ToString();
DataSet DsFinal = ClassHospital.GetDataSet(FinalQuery);
DataTable dt = DsFinal.Tables[0];
int i1 = 0;
//Iterate through the columns of the datatable to set the data bound field dynamically.
foreach (DataColumn col in dt.Columns)
{
//Declare the bound field and allocate memory for the bound field.
TemplateField bfield = new TemplateField();
//Initalize the DataField value.
bfield.HeaderTemplate = new GridViewTemplate(ListItemType.Header, col.ColumnName, 0, false);
if (i1 == 0)
{
//Initialize the HeaderText field value.
bfield.ItemTemplate = new GridViewTemplate(ListItemType.Item, col.ColumnName, 50, false);
}
else if (i1 == 1)
{
//Initialize the HeaderText field value.
bfield.ItemTemplate = new GridViewTemplate(ListItemType.Item, col.ColumnName, 150, false);
}
else
{
//Initialize the HeaderText field value.
bfield.ItemTemplate = new GridViewTemplate(ListItemType.Item, col.ColumnName, 100, true);
}
//Add the newly created bound field to the GridView.
GridView1.Columns.Add(bfield);
i1++;
}
//Initialize the DataSource
GridView1.DataSource = dt;
//Bind the datatable with the GridView.
GridView1.DataBind();
if (GridView1.Rows.Count>0)
{
BtnUpdate.Visible = true;
}
else
{
BtnUpdate.Visible = false;
}
}
protected void BtnUpdate_Click(object sender, EventArgs e)
{
try
{
for (int i = 0; i < GridView1.Rows.Count; i++)
{
for (int j = 0; j < GridView1.Columns.Count; j++)
{
Control c = GridView1.Rows[i].Cells[j].FindControl("tb1") as TextBox;
}
}
}
catch (Exception)
{
throw;
}
}
}
templete class
templete class
<pre lang="c#">
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
//A customized class for displaying the Template Column
public class GridViewTemplate : ITemplate
{
//A variable to hold the type of ListItemType.
ListItemType _templateType;
//A variable to hold the column name.
string _columnName;
int _width;
bool _IsEnabled;
//Constructor where we define the template type and column name.
public GridViewTemplate(ListItemType type, string colname,int W,bool E)
{
//Stores the template type.
_templateType = type;
//Stores the column name.
_columnName = colname;
_width = W;
_IsEnabled = E;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_templateType)
{
case ListItemType.Header:
//Creates a new label control and add it to the container.
Label lbl = new Label(); //Allocates the new label object.
lbl.Text = _columnName; //Assigns the name of the column in the lable.
container.Controls.Add(lbl); //Adds the newly created label control to the container.
break;
case ListItemType.Item:
//Creates a new text box control and add it to the container.
TextBox tb1 = new TextBox(); //Allocates the new text box object.
tb1.DataBinding += new EventHandler(tb1_DataBinding); //Attaches the data binding event.
tb1.Width=Unit.Pixel(_width); //Creates a column with size 4.
tb1.Enabled = _IsEnabled;
if (_IsEnabled==false)
{
tb1.BorderStyle = BorderStyle.None;
tb1.Font.Bold = true;
tb1.BackColor = Color.White;
tb1.ForeColor = Color.Red;
}
container.Controls.Add(tb1); //Adds the newly created textbox to the container.
break;
case ListItemType.EditItem:
//As, I am not using any EditItem, I didnot added any code here.
break;
case ListItemType.Footer:
CheckBox chkColumn = new CheckBox();
chkColumn.ID = "Chk" + _columnName;
container.Controls.Add(chkColumn);
break;
}
}
/// <summary>
/// This is the event, which will be raised when the binding happens.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void tb1_DataBinding(object sender, EventArgs e)
{
TextBox txtdata = (TextBox)sender;
GridViewRow container = (GridViewRow)txtdata.NamingContainer;
object dataValue = DataBinder.Eval(container.DataItem, _columnName);
if (dataValue != DBNull.Value)
{
txtdata.Text = dataValue.ToString();
txtdata.ToolTip = dataValue.ToString();
}
}
}
on btnupdate click my gridview become blank
i also want to retrieve text box value.
pl help
on btnupdate click my gridview become blank
i also want to retrieve text box value.
pl help
推荐答案
You can follow below steps to resolve the issue:
Step 1: Create a function - LoadData() and move all the code that you’ve in btnLoadClick_click() event.
Step 2: Call LoadData() from the Load button click event.
Step 3: Call LoadData() from the Update button click event too.
Explanation: Once the page is postback, all the data is lost from the page. You have to bind the data to the GridView control explicitly.
You can follow below steps to resolve the issue:
Step 1: Create a function - LoadData() and move all the code that you've in btnLoadClick_click() event.
Step 2: Call LoadData() from the Load button click event.
Step 3: Call LoadData() from the Update button click event too.
Explanation: Once the page is postback, all the data is lost from the page. You have to bind the data to the GridView control explicitly.
这篇关于gridview动态templte字段问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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