ADO.net Entity Gridview is null when RowUpdating event fired - c#

So I'm using ADO.net Entity Data model in an ASP.Net (C#) Web page. I am dynamically adding and retrieving data to my database using gridviews. I am using master pages, and my gridview is in a contentplaceholder. My only issue with this code is that when my RowUpdating event fires, the gridview is null. I can call by BindGV function, and then the rest of the code updates the database perfectly fine, with the original data from the database I just bound to it, since the database was not updated yet. In all events, if I change bindGV() to Gridview1.databind(), the gridview is null. I think the datasource the gridview is referencing is becoming null at the end of the event when the data connection is closed, is there anyway to prevent this?
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
onrowcancelingedit="GridView1_RowCancelingEdit"
onrowediting="GridView1_RowEditing" onrowupdating="GridView1_RowUpdating"
onrowdatabound="GridView1_RowDataBound"
>
<Columns>
<asp:TemplateField Visible="false">
<ItemTemplate>
<asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="lblId" runat="server" Text='<%# Eval("id") %>'></asp:Label>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Machine">
<ItemTemplate>
<asp:Label ID="lblMachine" runat="server" Text='<%# Eval("MachineName") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtMachine" runat="server" Text='<%# Eval("MachineName") %>'></asp:TextBox>
</EditItemTemplate>
<ControlStyle Width="60px" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Dept">
<ItemTemplate>
<asp:Label ID="lblDept" runat="server" Text='<%# Eval("WorkCenterFK") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddldept" runat="server" >
</asp:DropDownList>
</EditItemTemplate>
<ControlStyle Width="120px" />
</asp:TemplateField>
<asp:CommandField HeaderText="Actions" ShowEditButton="true" ShowDeleteButton="True"
ControlStyle-Width="50px" CausesValidation="false">
</asp:CommandField>
</Columns>
protected void BindGV()
{
QualityEntities database = new QualityEntities();
GridView1.DataSource = (from m in database.Machines
from d in database.Workcenters
where m.WorkcenterFK == d.id
select
new { id = m.id, MachineName = m.MachineName, WorkCenterFK = d.WorkCenterName }); ;
GridView1.DataBind();
}
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack) BindGV();
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
BindGV();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
BindGV();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
QualityEntities database = new QualityEntities();
BindGV();
Int32 id = Convert.ToInt32(((Label)GridView1.Rows[e.RowIndex].FindControl("lblId")).Text);
DropDownList ddl = ((DropDownList)GridView1.Rows[e.RowIndex].FindControl("ddlDept"));
TextBox txt = ((TextBox)GridView1.Rows[e.RowIndex].FindControl("txtMachine"));
Machine mch = (from m in database.Machines where m.id == id select m).Single();
mch.MachineName = txt.Text;
mch.WorkcenterFK = Convert.ToInt32(ddl.SelectedItem.Value);
database.SaveChanges();
GridView1.EditIndex = -1;
BindGV();
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
QualityEntities database = new QualityEntities();
DropDownList temp = (DropDownList)(e.Row.FindControl("ddlDept"));
if (temp != null)
{
temp.DataSource = (from w in database.Workcenters select w);
temp.DataTextField = "WorkCenterName";
temp.DataValueField = "id";
temp.DataBind();
Int32 id = Convert.ToInt32(((Label)e.Row.FindControl("lblId")).Text);
}
}

Not sure why the GridView is null, but instead of using a member variable i would use the sender of the event which is always the source of the event (in this case the GridView)
// ...
GridView grid = (GridView)sender;
Int32 id = Convert.ToInt32(((Label)grid.Rows[e.RowIndex].FindControl("lblId")).Text);
// ...

Related

Cannot find hidden input control on row data bound event

Here is my aspx file content.
<asp:UpdatePanel ID="UpdatePanel1" runat="server" OnUnload="UpdatePanel_Unload">
<ContentTemplate>
<table>
<tr>
<td>
<input id="hdnAID" type="hidden" runat="server" />
<asp:GridView ID="GridView1" runat="server" OnRowCancelingEdit="GridView1_RowCancelingEdit"
OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" OnRowDataBound="GridView1_RowDataBound" OnDataBound="GridView1_DataBound"
DataKeyNames="GeneralSettingID" EnableViewState="true">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<GridEditPopupMenu:GridEditPopupMenu ID="GridEditPopupMenu1" runat="server" currenttemplate="ItemTemplate" ShowDeleteLink="0" />
</ItemTemplate>
<EditItemTemplate>
<GridEditPopupMenu:GridEditPopupMenu ID="GridEditPopupMenu1" runat="server" currenttemplate="EditItemTemplate" />
</EditItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="GeneralSettingID" HeaderText="SettingNo" ReadOnly="true" />
<asp:TemplateField HeaderText="SettingName">
<ItemTemplate>
<asp:Label ID="Label25" runat="server" Text='<%# Eval("GeneralSettingName") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingName" onfocus="this.blur();" runat="server" Text='<%# Bind("GeneralSettingName") %>'
Width="350px" />
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Values">
<ItemTemplate>
<asp:Label ID="Label23" runat="server" Text='<%# Eval("GeneralSettingValue") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingValue" runat="server" Text='<%# Bind("GeneralSettingValue") %>'
Width="600px" TextMode="MultiLine" Rows="6" />
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Company1">
<ItemTemplate>
<asp:Label ID="Label28" runat="server" Text='<%# Eval("GeneralSettingCompany") %>' />
</ItemTemplate>
<ItemTemplate>
<asp:TextBox ID="txtUpdateGeneralSettingCompany" runat="server" Text='<%# Bind("GeneralSettingCompany") %>'
Width="100px" TextMode="MultiLine" Rows="1" Enabled="false" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Company2">
<ItemTemplate>
<asp:DropDownList ID="drpCompanyList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="drpCompanyList_SelectedIndexChanged" DataTextField="CompanyName" DataValueField="CompanyID"></asp:DropDownList>
<input id="hdnCompanyId" type="hidden" value='<%# Eval("GeneralSettingCompany") %>' runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>
Here is the .cs side .
private LMSDataAccess.LookupsDataContext LkpDC = new LMSDataAccess.LookupsDataContext(ConfigFile.DBConnStr);
private System.Collections.Generic.List<LMSDataAccess.GeneralSetting> GeneralSettingList = null;
protected void Page_Load(object sender, EventArgs e)
{
base.ModuleID = 27;
if (!IsPostBack)
{
if (Request["AID"] != null)
hdnAID.Value = Request["AID"];
BindData();
}
}
private void BindData()
{
GeneralSettingList = LkpDC.GeneralSettingsGetAll(Common.NVLInt(hdnAID.Value),null).ToList();
GridView1.DataSource = GeneralSettingList;
GridView1.DataBind();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
BindData();
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
BindData();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
TextBox txtUpdateGeneralSettingName = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txtUpdateGeneralSettingName");
TextBox txtUpdateGeneralSettingValue = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txtUpdateGeneralSettingValue");
var hdnCompany = (HiddenField)GridView1.Rows[e.RowIndex].FindControl("hdnCompanyId") as HiddenField;
string KeyValue = GridView1.DataKeys[e.RowIndex].Value.ToString();
LkpDC.GeneralSettingsUpdate(Convert.ToInt32(KeyValue),
txtUpdateGeneralSettingName.Text,
txtUpdateGeneralSettingValue.Text,
Convert.ToInt32(hdnCompany.Value));
GridView1.EditIndex = -1;
BindData();
ResultCode = 0;
}
protected List<LMSDataAccess.Company> GetAllCompanies()
{
System.Collections.Generic.List<LMSDataAccess.Company> CompanyList = null;
LMSDataAccess.OrganizationDataContext OrgDC = new LMSDataAccess.OrganizationDataContext(ConfigFile.DBConnStr);
CompanyList = OrgDC.CompaniesGetAll(null).ToList();
return CompanyList;
}
protected void drpCompanyList_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList ddl = (DropDownList)sender;
GridViewRow row = (GridViewRow)ddl.Parent.Parent;
var hdnCompany = row.FindControl("hdnCompanyId") as HiddenField;
hdnCompany.Value = ddl.SelectedValue;
}
protected void GridView1_RowDataBound(object sender,GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
var ddl = e.Row.FindControl("drpCompanyList") as DropDownList;
//here is the problem.
var hdn = e.Row.FindControl("hdnCompanyId") as HiddenField;
if (ddl != null)
{
ddl.DataSource = GetAllCompanies();
ddl.DataValueField = "CompanyID";
ddl.DataTextField = "CompanyName";
ddl.DataBind();
}
}
}
My beloved problem is not being able to get hdnCompanyId element when GridView1_RowDataBound and drpCompanyList_SelectedIndexChangedfired.I am always getting null.(as showed at the commented line )
I have tried under GridView1_RowDataBound event method like e.Row.FindControl("hdnCompanyId")
but it did not work.
My final aim is to setting and getting this element to control selected items of my dropdownlist.
I think the code is well written but I guess I am missing something about hierarchy of the user control elements.
Can you help me about what I am missing?
I have found that the problem was choosing the wrong casting type of the input.It must be HtmlInputHidden rather than HiddenField.I hope someone can get useful info from that question.

OnRowUpdating Does not take value of edit template textbox

I am trying to update a value in my gridview on row updating. However, it refuses to take in the value written in the textbox. I populate the gridview if the page is not post back. Help!
GRIDVIEW:
<asp:UpdatePanel runat="server" UpdateMode=Conditional><ContentTemplate>
<asp:GridView runat="server" ID="searchGV" AutoGenerateColumns="False" GridLines="None"
CssClass="mGrid" EmptyDataText="The Search Did Not Return Any Results"
PagerStyle-CssClass="pgr" AlternatingRowStyle-CssClass="alt" Width="100%" OnRowCancelingEdit="searchGV_RowCancelingEdit"
OnRowEditing="searchGV_RowEditing" DataKeyNames="media_id" OnRowUpdating="searchGV_RowUpdating">
<Columns>
<asp:BoundField DataField="media_id" Visible="false" HeaderText="" />
<asp:BoundField DataField="dir_path" Visible="false" HeaderText="Dir" />
<asp:TemplateField HeaderText="Date Taken" >
<ItemTemplate>
<asp:LinkButton ID="dateLinkCsBtn" OnClientClick='<%#Eval("dir_path","Javascript:return test(\"{0}\",event);")%>'
runat="server" Text='<%# Bind("date") %>'></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Media Type">
<ItemTemplate>
<asp:Label runat="server" ID="mediaTypeLbl" Text='<%#Eval("description") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Alias File Name">
<ItemTemplate>
<asp:Label runat="server" ID="aliasFileName" Text='<%#Bind("alias_file_name") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox runat="server" Text='<%#Bind("alias_file_name") %>' ID="updateAliasTxt"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" />
</Columns>
</asp:GridView>
</ContentTemplate></asp:UpdatePanel>
CODE BEHIND:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
FillGrid();
}
}
protected void searchGV_RowEditing(object sender, GridViewEditEventArgs e)
{
searchGV.EditIndex = e.NewEditIndex;
FillGrid();
}
protected void searchGV_RowCancelingEdit(object sender,
GridViewCancelEditEventArgs e)
{
searchGV.EditIndex = -1;
FillGrid();
}
public void FillGrid()
{
Media_DAO media_query = new Media_DAO();
searchGV.DataSource = media_query.get_search_media(alias_file_name_txt.Text.Trim(), Convert.ToInt16(mediaTypeDDL.SelectedValue),
from_date_txt.Text.Trim(), to_date_txt.Text.Trim(), Convert.ToInt16(Session["user_id"]));
searchGV.DataBind();
}
protected void searchGV_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewRow row = searchGV.Rows[e.RowIndex];
TextBox new_alias = (TextBox)searchGV.Rows[e.RowIndex].FindControl("updateAliasTxt");
int media_id = Convert.ToInt16(searchGV.DataKeys[e.RowIndex]["media_id"]);
Media_DAO media_query2 = new Media_DAO();
media_query2.update_alias_name_by_id(media_id, new_alias.Text.Trim(), Convert.ToInt16(Session["user_id"]));
searchGV.EditIndex = -1;
FillGrid();
}
while declaring the grid you have specified only 1 *data key value*
asDataKeyNames="media_id"
DateKeys for grid view is stored in array format starting from 0.
The error may be in getting the media_id while updating. You need to change it as follows.
protected void searchGV_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewRow row = searchGV.Rows[e.RowIndex];
TextBox new_alias = (TextBox)searchGV.Rows[e.RowIndex].FindControl("updateAliasTxt");
int media_id = Convert.ToInt16(e.Keys[0]); //this will get the media_id
Media_DAO media_query2 = new Media_DAO();
media_query2.update_alias_name_by_id(media_id, new_alias.Text.Trim(), Convert.ToInt16(Session["user_id"]));
searchGV.EditIndex = -1;
FillGrid();
}
Since the earlier method was searchGV.DataKeys[e.RowIndex]["media_id"] , you might not get the media_id value if the row number which you are trying to edit is greater than 1.
The DataKeys property of GridView returns a collection of DataKey objects that represents the data key value of each row for a GridView. Thus, DataKeys[1] gives 2nd row, DataKeys[4] gives 5th row ...
Therefore, you need to use either the Value OR the Values property to access the value of a key field.
Rather than doing this:
int media_id = Convert.ToInt16(searchGV.DataKeys[e.RowIndex]["media_id"]);
do this:
int media_id = Convert.ToInt16(searchGV.DataKeys[e.RowIndex].Values["media_id"]);
// You can also use the Value property which gives the key value at index 0
int media_id = Convert.ToInt16(searchGV.DataKeys[e.RowIndex].Value);

GridView dissapears when clicking on Edit-Button

I've searched for two days now and can't find a solution for my problem. I'm programming a webpart with connection to a database with Visual Studio.
So I've made a GridView to show some data listed in the database and the user is able to edit and update the data in it. Before you see the GridView, you have to click the button "load table". But when I click on "edit" on the GridView, the GridView dissapears and only shows up when I click the button "load table" again, with the GridView in edit-mode.
ASP
<asp:Button ID="btnload" runat="server" Text="load table"
onclick="btnload_Click" />
<asp:GridView ID="gridtable" runat="server" BackColor="White"
BorderColor="#CC9966" BorderStyle="None" BorderWidth="1px"
CellPadding="4" EnableModelValidation="True"
OnRowCancelingEdit="gridtable_RowCancelingEdit"
OnRowEditing="gridtable_RowEditing"
OnRowUpdating="gridtable_RowUpdating" >
<FooterStyle BackColor="#FFFFCC" ForeColor="#330099" />
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="#FFFFCC" />
<PagerStyle BackColor="#FFFFCC" ForeColor="#330099" HorizontalAlign="Center" />
<RowStyle BackColor="White" ForeColor="#330099" />
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="#663399" />
<Columns>
<asp:TemplateField HeaderText="P_number">
<ItemTemplate>
<%#Eval("P_number")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="textbox1" runat="server" Text='<%#Eval("P_number")%>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="lastname">
<ItemTemplate>
<%#Eval("lastname")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="textbox2" runat="server" Text='<%#Eval("lastname")%>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="PN_ch">
<ItemTemplate>
<%#Eval("PN_ch")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="textbox3" runat="server" Text='<%#Eval("PN_ch")%>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="lastname_ch">
<ItemTemplate>
<%#Eval("lastname_ch")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="textbox4" runat="server" Text='<%#Eval("lastname_ch")%>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="workplace">
<ItemTemplate>
<%#Eval("workplace")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="textbox5" runat="server" Text='<%#Eval("workplace")%>'>
</asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
C#
public SqlDataSource datasource;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnload_Click(object sender, EventArgs e)
{
openConnection(getconstring());
gridtable.AutoGenerateColumns = false;
gridtable.AutoGenerateEditButton = true;
datasource = new SqlDataSource(getconstring(), "SELECT * FROM T_Employees");
BindData();
}
public void BindData()
{
try
{
gridtable.DataSource = datasource;
gridtable.DataBind();
}
catch (Exception e)
{
//Do something
}
}
protected void gridtable_RowEditing(object sender, GridViewEditEventArgs e)
{
gridtable.EditIndex = e.NewEditIndex;
BindData();
}
protected void gridtable_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
//get EditIndex
GridViewRow row = gridtable.Rows[e.RowIndex];
// save changes
string pnumber = ((row.Cells[1].Controls[0]).ToString());
string lastname = ((row.Cells[2].Controls[0]).ToString());
string pn_ch = ((row.Cells[3].Controls[0]).ToString());
string lastname_ch = ((row.Cells[4].Controls[0]).ToString());
string workplace = ((row.Cells[5].Controls[0]).ToString());
//Update
datasource.UpdateCommand = "UPDATE T_Employees SET P_number='"+pnumber+"', lastname='"
+lastname+"', PN_ch='"+pn_ch+"', lastname_ch='"
+lastname_ch+"', workplace='"+workplace+"'";
datasource.Update();
//reset EditIndex
gridtabelle.EditIndex = -1;
//Bind data
BindData();
}
protected void gridtable_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
gridtable.EditIndex = -1;
BindData();
}
You need to store the datasource in session in the button click:
protected void btnload_Click(object sender, EventArgs e)
{
openConnection(getconstring());
gridtable.AutoGenerateColumns = false;
gridtable.AutoGenerateEditButton = true;
datasource = new SqlDataSource(getconstring(), "SELECT * FROM T_Employees");
Session["datasource "] = datasource
BindData();
}
Then change your bind to this:
public void BindData()
{
try
{
gridtable.DataSource = Session["datasource "] ;
gridtable.DataBind();
}
catch (Exception e)
{
//Do something
}
}
You also need to add this to the web.config:
<system.web>
<pages enableSessionState="true">
</system.web>
Or this to the page:
<%#Page enableSessionState="true">
You may just declare your datasource as in your aspx file and you're done. If you then need to bind your grid after a button click, then you have to store somewhere (eg. viewstate) a flag (boolean value) to indicate if your grid has to be binded or not. Then bind the grid only if that flag is true.
Don't need to use session at all.
Eg:
protected void Page_Load(object sender, EventArgs e)
{
if (!isPostBack){
ViewState["FLAG"] = false;
}
else{
if ((bool)ViewState["FLAG"]) BindData();
}
}
protected void btnload_Click(object sender, EventArgs e)
{
ViewState["FLAG"] = true;
}
Looking # previous answers, please consider that even if you choose ViewState or Session (each of these have their own advantages / disadvantages), you don't need to store ridundant data. In your case, just a single bit is enough, as you have the code - in your page - to build/bind the data source without storing it interely.

GridView into UpdatePanel fires OnRowUpdating event : but I can see only the controls inside ItemTemplate instead of EditItemTemplate?

As i was written in the title, the problem is very funny :
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="id_Newsletter" HeaderStyle-BackColor="Black"
HeaderStyle-ForeColor="White" RowStyle-BackColor="DarkGray" AlternatingRowStyle-BackColor="LightGray" PageSize="6" AllowPaging="true"
AllowSorting="true" ShowHeaderWhenEmpty="true" EmptyDataText="La tabella non contiene dati" EnableViewState="true" RowStyle-Wrap="true"
PagerStyle-HorizontalAlign="Left" PagerStyle-BorderWidth="0" BorderWidth="0" OnRowCommand="GridView_RowCommand"
OnRowCancelingEdit="GridView_RowCancelingEdit" OnRowUpdating="GridView_RowUpdating" OnRowDeleting="GridView_RowDeleting"
OnPageIndexChanging="GridView_PageIndexChanging" OnSorting="GridView_Sorting" OnRowEditing="GridView_RowEditing" CssClass="NewsletterManager_GridView" >
<Columns>
<asp:TemplateField ItemStyle-HorizontalAlign="Center" HeaderText="Indirizzo Email" HeaderStyle-Width="275" SortExpression="emailNewsletter">
<ItemTemplate>
<asp:Label ID="lbl_emailNewsletter" runat="server" Text='<%# Eval("emailNewsletter") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="lbl_emailNewsletter" runat="server" Text='<%# Eval("emailNewsletter") %>' Visible="false" ></asp:Label>
<asp:TextBox ID="txt_emailNewsletter" runat="server" Text='<%# Bind("emailNewsletter") %>'></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField ItemStyle-HorizontalAlign="Center" HeaderText="Azioni" HeaderStyle-Width="100">
<EditItemTemplate>
<asp:ImageButton ID="Img_Aggiorna" runat="server" CommandName="Update" ImageUrl="~/images/GridIcon/update.png" ToolTip="Aggiorna" />
<asp:ImageButton ID="Img_Annulla" runat="server" CommandName="Cancel" ImageUrl="~/images/GridIcon/undo.png" ToolTip="Annulla" />
</EditItemTemplate>
<ItemTemplate>
<asp:ImageButton ID="Img_Modifica" runat="server" CommandName="Edit" ImageUrl="~/images/GridIcon/edit.png" ToolTip="Modifica" />
<asp:ImageButton ID="Img_Cancella" runat="server" CommandName="Delete" ImageUrl="~/images/GridIcon/delete.png" OnClientClick="return confirm('Sei sicuro di voler cancellare l\'email?');" ToolTip="cancella" />
</ItemTemplate>
</asp:TemplateField>
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
LoadGridView(GridView1, -1, 0);
lbl_result.Text = String.Empty;
}
protected void GridView_RowEditing(Object sender, GridViewEditEventArgs e)
{
LoadGridView(((GridView)sender), e.NewEditIndex, ((GridView)sender).PageIndex);
}
protected void GridView_RowUpdating(Object sender, GridViewUpdateEventArgs e)
{
NewsLetterBL newsBl = new NewsLetterBL();
String oldmail = ((Label)((GridView)sender).Rows[e.RowIndex].FindControl("lbl_emailNewsletter")).Text;
String newmail = ((TextBox)((GridView)sender).Rows[e.RowIndex].FindControl("txt_emailNewsletter")).Text;
if (newsBl.ModifyWrongEmail(oldmail, newmail))
lbl_result.Text = "Modify Done";
else lbl_result.Text = newsBl.LastMessage;
LoadGridView(((GridView)sender), -1, ((GridView)sender).PageIndex);
}
protected void LoadGridView(GridView GV, int EditIndex, int PageIndex)
{
NewsLetterBL newsBl = new NewsLetterBL();
DataView dw = new DataView(newsBl.getFullNewsletter());
String SortExpression = GV.ID.ToString() + "_SortExpression";
if (ViewState[SortExpression] != null) dw.Sort = (String)ViewState[SortExpression];
GV.DataSource = dw;
GV.PageIndex = PageIndex;
GV.EditIndex = EditIndex;
GV.DataBind();
}
When I try to access to the txt_emailNewsletter control into the row in edit mode from the GridView_RowUpdating that handle the OnRowUpdating event of the GridView1, the element throws a NullReferenceException, but the lbl_emailNewsletter control can be founded.
The labels into ItemTemplate and EditItemTemplate have the same ID (lbl_emailNewsletter): if I change the ID of the label into the ItemTemplate, both the String oldmail and newmail throws an exception of null Reference ; clearly the problem is that when I click on ImageButton Img_Aggiorna with CommandName="Update", ASP.NET for a mysterious reason Find only controls of ItemTemplate instead of EditItemTemplate from the edited row.
GridView event "OnRowUpdating" is useful only if you use a datasource : in this case is possible to access to the Dictionary e.OldValues[] or e.NewValues[] and get correctly the old and new values.
I have solved the problem using the event "OnRowCommand" with a personalized CommandName and a CommandArgument with the old values : in this case is possible to access to all the controls inside the edited row in the GridView with the new values.
<asp:ImageButton ID="Img_Update" runat="server" CommandName="Change" CommandArgument='<%# Eval("emailNewsletter") %>' ImageUrl="~/images/GridIcon/update.png" ToolTip="Update" />
protected void GridView_RowCommand(Object sender, GridViewCommandEventArgs e)
{
switch (e.CommandName)
{
case "Change":
ImageButton btnNew = e.CommandSource as ImageButton;
GridViewRow row = btnNew.NamingContainer as GridViewRow;
TextBox txt_emailNewsletter = row.FindControl("txt_emailNewsletter") as TextBox;
if ( !CheckEmail(e.CommandArgument.ToString()) || !CheckEmail(txt_emailNewsletter.Text) )
lbl_result.Text = "ERROR : Email not Valid";
else {
if (txt_emailNewsletter.Text.Trim().ToLower() == e.CommandArgument.ToString())
lbl_result.Text = "Email values are indentical";
else
{
//Business Layer Call
NewsLetterBL newsBl2 = new NewsLetterBL();
if (newsBl2.ModifyWrongEmail(e.CommandArgument.ToString(), txt_emailNewsletter.Text.Trim().ToLower()))
lbl_result.Text = "Email Changed";
else
lbl_result.Text = "ERROR : " + newsBl2.LastMessage;
}
}
LoadDataForGridView(((GridView)sender));
BindGridView(((GridView)sender), -1, ((GridView)sender).PageIndex);
break;
}
}

How to get the Command Argument on Row Data bound Event of gridview

i am binding the values to gridview like this
<asp:GridView ID="grdViewAttachment_Client" runat="server" Width="615px" AutoGenerateColumns="False" GridLines="None" CssClass="grid-view" OnRowCommand="grdViewAttachment_Client_RowCommand">
<Columns>
<asp:TemplateField HeaderText="Attachment" HeaderStyle-CssClass="hedding2">
<ItemTemplate>
<asp:LinkButton ID="lnkbtnAttachments" runat="server" Text="Delete" CommandName="Delete" CommandArgument='<%#Eval("AttachmentId") %>' ></asp:LinkButton>
</ItemTemplate>
<HeaderStyle/>
</asp:TemplateField>
<asp:TemplateField HeaderText="Attachment" HeaderStyle-CssClass="hedding2">
<ItemTemplate>
<%--<asp:LinkButton ID="lnkbtnAttachments" runat="server" Text='<%#Eval("AttachmentName") %>' CommandName='<%#Eval("AttachmentName")%>' CommandArgument='<%#Eval("AttachmentId") %>'></asp:LinkButton>--%>
<asp:LinkButton ID="LinkButton1" runat="server" Text='<%#Eval("AttachmentName") %>' CommandName='<%#Eval("AttachmentName")%>' ></asp:LinkButton>
</ItemTemplate>
<HeaderStyle/>
</asp:TemplateField>
<asp:TemplateField HeaderText="AssignedTo" HeaderStyle-CssClass="hedding2">
<ItemTemplate>
<asp:Label ID="lblAssignedTo" Text='<%#Eval("AssignedTo") %>' runat="server" CssClass="body-text"></asp:Label>
</ItemTemplate>
<HeaderStyle />
</asp:TemplateField>
<asp:TemplateField HeaderText="CreationDate" HeaderStyle-CssClass="hedding2">
<ItemTemplate>
<asp:Label ID="lblCreationDate" Text='<%#Eval("CreationDate") %>' runat="server" CssClass="body-text"></asp:Label>
</ItemTemplate>
<HeaderStyle />
</asp:TemplateField>
</Columns>
</asp:GridView>
In my row command event i write as follows code
protected void grdViewAttachment_Client_RowCommand(object sender, GridViewCommandEventArgs e)
{
SqlConnection m_Conn = new SqlConnection(Utilities.ConnectionString());
SqlCommand m_oCmd;
int iStID = int.Parse(e.CommandArgument.ToString());
int pk = 0;
int.TryParse(e.CommandArgument as string, out pk);
string strStoreProcName = null;
DataSet oDS1 = new DataSet();
if (e.CommandName == "Delete")
{
strStoreProcName = StoredProcNames.Attachments_uspDeleteAttachs;
m_oCmd = new SqlCommand(strStoreProcName, m_Conn);
m_oCmd.CommandType = CommandType.StoredProcedure;
m_oCmd.Parameters.Add("#AttachmentId", SqlDbType.Int).Value = Convert.ToInt32(e.CommandArgument.ToString());
m_Conn.Open();
m_oCmd.ExecuteNonQuery();
AttachmentDetails();
}
string fname = e.CommandName.ToString();
}
But i am not getting the value i am getting the exception as Input string was not in correct format can any one help me
es #Muhammad Akhtar was right .It should be like
int iStID = Convert.ToInt32(gridName.DataKeys[Convert.ToInt32(e.CommandArgument.ToString())].Value);
Specify Datakey property in your data grid . and you can access the data key value of the current row as above
add datakey name to your statement
ID_COLUMN should be a column from data table which you are binding to gridview
Write this code for row Created
protected void grdViewAttachment_Client_RowCreated(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
LinkButton lnkbtnAttachments=(LinkButton)e.Row.FindControl("lnkbtnAttachments");
lnkbtnAttachments.CommandArgument = e.Row.RowIndex.ToString();
// similarly write for other controls
}
}
Do not use Delete standard commandName otherwise you have to handle the "RowDeleting" event.
Take a look at this sample:
.aspx markup
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
onrowcommand="GridView1_RowCommand">
<Columns>
<asp:TemplateField>
<ItemTemplate>
Data :
<asp:Label ID="Label1" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
<asp:LinkButton ID="btnDelete" runat="server"
CommandArgument='<%# Eval("No") %>' CommandName="Del">Delete</asp:LinkButton>
<asp:LinkButton ID="btnShow" runat="server" CommandArgument='<%# Eval("No") %>'
CommandName="Show">Show</asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Code behind
public class Data
{
public int No { get; set; }
public string Name { get; set; }
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
List<Data> list = new List<Data>()
{
new Data(){ No=1, Name="A"},
new Data(){ No=2, Name="B"},
new Data(){ No=3, Name="C"}
};
GridView1.DataSource = list;
GridView1.DataBind();
}
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "Del")
{
Response.Write("Delete : " + e.CommandArgument);
}
else
if (e.CommandName == "Show")
{
Response.Write("Show : " + e.CommandArgument);
}
}
As you are not passing command Argument this will always give null reference . Try this in your control where ever you required.
<asp:LinkButton ID="LinkButton1" runat="server" Text='<%#Eval("AttachmentName") %>' CommandName='<%#Eval("AttachmentName")%>' CommandArgument='<%#Eval("AttachmentId") %>'>
<ItemTemplate>
<asp:LinkButton ID="lnkDetails" runat="server" CommandName="Details" CommandArgument='<%#Eval("ID")%>'
ToolTip="View Details">View</asp:LinkButton>
</ItemTemplate>
protected void gvmain_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "Details")
{
int id = Convert.ToInt32(e.CommandArgument);
Response.Redirect("~/MEMBER/UploadedDocList.aspx?id=" + id, false);
}
}

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