Capture DropDownList Index Change event inside of grid View - asp.net

I am trying to capture the SelectedIndexChanged event for a drop down list I have put inside of a gridview control. It posts back fine, but does not go into my SelectedIndexChanged event handler. Here is my code
DropDownList myddl;
protected void Page_Load(object sender, EventArgs e)
{
this.myGridview.RowDataBound += new GridViewRowEventHandler(myGridview_RowDataBound);
myddl = new DropDownList();
myddl.SelectedIndexChanged += new EventHandler(myddl_SelectedIndexChanged);
if (!Page.IsPostBack)
{
List<Team> teams = giveMeTeams();
this.myGridview.DataSource = teams;
this.myGridview.AutoGenerateColumns = false;
BoundField col1 = new BoundField();
col1.DataField = "Name";
this.myGridview.Columns.Add(col1);
BoundField col2 = new BoundField();
col2.DataField = "Sport";
this.myGridview.Columns.Add(col2);
BoundField col3 = new BoundField();
col3.DataField = "Status";
this.myGridview.Columns.Add(col3);
this.myGridview.DataBind();
}
}
void myGridview_RowDataBound(object sender, GridViewRowEventArgs e)
{
myddl = new DropDownList();
myddl.SelectedIndexChanged += new EventHandler(myddl_SelectedIndexChanged);
List<string> items = new List<string>();
items.Add("good");
items.Add("bad");
myddl.DataSource = items;
myddl.AutoPostBack = true;
myddl.DataBind();
e.Row.Cells[2].Controls.Add(myddl);
}
void myddl_SelectedIndexChanged(object sender, EventArgs e)
{
string temp = "In Here"; //neve hits this code
}
private List<Team> giveMeTeams()
{
Teams teams = new Teams();
teams.Add(new Team("RedWings", "Hockey", "good"));
teams.Add(new Team("Lions", "Football", "bad"));
teams.Add(new Team("Packers", "Football", "good"));
return teams;
}
Any help is greatly appreciated.
Thanks,
Edited based on Comments
I have tried as you suggested...and am still not capturing the post back. here is my new code
void myGridview_RowCreated(object sender, GridViewRowEventArgs e)
{
DropDownList myddl = new DropDownList();
myddl = new DropDownList();
myddl.SelectedIndexChanged += new EventHandler(myddl_SelectedIndexChanged);
myddl.ID = "MyID" + e.Row.RowIndex.ToString();
e.Row.Cells[2].Controls.Add(myddl);
}
void myGridview_RowDataBound(object sender, GridViewRowEventArgs e)
{
DropDownList myddl = e.Row.FindControl("MyID" + e.Row.RowIndex.ToString()) as DropDownList;
//myddl.SelectedIndexChanged += new EventHandler(myddl_SelectedIndexChanged);
List<string> items = new List<string>();
items.Add("good");
items.Add("bad");
myddl.DataSource = items;
myddl.DataMember = "Status";
myddl.AutoPostBack = true;
myddl.DataBind();
e.Row.Cells[2].Controls.Add(myddl);
}
it is still not going into my myddl_SelectedIndexChanged() eventhandler.

Create that Dropdownlist in RowCreated of the Grid and assign an ID to it. Get the refrence to these Dropdowns in RowDataBound via e.Row.FindControl("MyDropdownlistID") and bound them to the Datasource. Create distinct Dropdownlist instances instead of referencing always the same

Related

why my function doesn't execute after clicking dynamically created button

here is my scenarioton : if !page.Ispostback i fill a dropdown with data from database!
Also in the page there is a butron and onclick it gets one id from database and crates one panel IN WHIH THERE IS DYNAMICALLY CREATED BUTTON. The PROBLEM IS WHEN I CLICK THIS DYNAMICALLY CREATED BUTTON _ JUST NOTHING HAPPENS AND I CANT EXPLAIN WHY.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ddlLanguages.DataSource = this.catRep.GetAllAvailableLanguages();
ddlLanguages.DataBind();
}
//IEnumerable<CatgoriesLanguages> allcategories = this.catRep.GetAllCategoriesByID(1)
}
protected void btnAddNew_Click(object sender, EventArgs e)
{
inseredID = this.catRep.AddCategory();
Label mylab = new Label();
mylab.Text = "Yeeee" + inseredID;
Page.FindControl("form1").Controls.Add(mylab);
Panel myFieldSet = new Panel();
myFieldSet.GroupingText= "Add New Category";
Label lblTitle = new Label();
lblTitle.Text="Title: ";
myFieldSet.Controls.Add(lblTitle);
TextBox txbTitle = new TextBox();
txbTitle.ID = "txbTitle";
myFieldSet.Controls.Add(txbTitle);
myFieldSet.Controls.Add(new LiteralControl("<br />"));
Label lblShrtDescrpt = new Label();
lblShrtDescrpt.Text = "Short Description: ";
myFieldSet.Controls.Add(lblShrtDescrpt);
TextBox txbShrtDescrpt = new TextBox();
txbShrtDescrpt.ID = "txbShrtDescrpt";
myFieldSet.Controls.Add(txbShrtDescrpt);
myFieldSet.Controls.Add(new LiteralControl("<br />"));
Label lblDescrpt = new Label();
lblDescrpt.Text = "Description: ";
myFieldSet.Controls.Add(lblDescrpt);
TextBox txbDescrpt = new TextBox();
txbDescrpt.ID = "txbDescrpt";
myFieldSet.Controls.Add(txbDescrpt);
Button btnAddcategorieslanguage = new Button();
btnAddcategorieslanguage.Click += new EventHandler(btnAddcategorieslanguage_Click);
myFieldSet.Controls.Add(btnAddcategorieslanguage);
Page.FindControl("form1").Controls.Add(myFieldSet);
}
public void btnAddcategorieslanguage_Click(object sender, EventArgs e)
{
TextBox txbTitle = (TextBox)FindControl("txbTitle");
TextBox txbShrtDescrpt = (TextBox)FindControl("txbShrtDescrpt");
TextBox txbDescrpt = (TextBox)FindControl("txbDescrpt");
this.catRep.AddCategoriesLanguages(11, 2, "malee", "tariiiiii", "liliiii");
}
You need to create all dynamically added controls in page Init or page load event too.
Something like this:
protected void Page_Load(object sender, EventArgs e)
{
if(ThereIsDynamicControl())
{
//You can set some session or viewState in the btnAddNew_Click to determine whether you need to add dynamic controls again here or not.
}
if (!IsPostBack)
{
ddlLanguages.DataSource = this.catRep.GetAllAvailableLanguages();
ddlLanguages.DataBind();
}
//IEnumerable<CatgoriesLanguages> allcategories = this.catRep.GetAllCategoriesByID(1);
}

how to add footer template dynamically in asp.net

I have created a gridview dynamically. There is template fields described in designing portion. All the columns were created thru code behind as follows. Its works fine. Here I can listed the pages for each rows. But I dont know how to implement the sum of pages in the footer template thru code behind.
TemplateField Pages = new TemplateField();
Pages.HeaderText = "Pages";
Pages.ItemTemplate = new GridViewTemplate_Pages();
gv1.Columns.Add(Pages);
public class GridViewTemplate_Pages : ITemplate
{
void ITemplate.InstantiateIn(Control container)
{
Label PagesLabel = new Label();
PagesLabel.DataBinding += new EventHandler(this.PagesLabel_DataBinding);
container.Controls.Add(PagesLabel);
}
void PagesLabel_DataBinding(object sender, EventArgs e)
{
Label lbl1 = (Label)sender;
GridViewRow row = (GridViewRow)lbl1.NamingContainer;
lbl1.Text = DataBinder.Eval(row.DataItem, "PagesReceived").ToString();
}
}
Given ShowFooter="True" in aspx page and RowDataBound written separately. The following code works fine if I given footer template in aspx page but do not know how to get the result in programmatically. Please advice.
protected void gv1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int RowTotalPages = Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "PagesReceived"));
TotalPages = TotalPages + RowTotalPages;
}
if (e.Row.RowType == DataControlRowType.Footer)
{
Label m = (Label)e.Row.FindControl("gv1TotalPages");
m.Text = TotalPages.ToString();
}
}
You can create the footer to a gridview like this.
//Code
GridView gv = new GridView();
gv.RowCreated += delegate(object dsender, GridViewRowEventArgs ge)
{
if (ge.Row.RowType == DataControlRowType.Footer)
ge.Row.Cells[0].Text = "Something";
};
gv.AutoGenerateColumns = false;
gv.ShowFooter = true;
BoundField bf = new BoundField();
bf.HeaderText = "col 1";
bf.DataField = "Length";
gv.Columns.Add(bf);
gv.DataSource = new string[] { "One", "Two", "Three" };
gv.DataBind();
Form.Controls.Add(gv);
This is for the dynamically created gridview and a footer. You can change accordingly.
Its a silly thing. I made it complex. I need the sum of pages in the footer row, then why should I think and confuse about GridViewTemplate and Itemplate class. Simply I added the Total pages in the session and recollect it in the DataControlRowType.Footer. Here is the code:
protected void gv1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int RowTotalPages = Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "PagesReceived"));
int RowTotalCharges = Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "ChargesReceived"));
TotalPages = TotalPages + RowTotalPages;
TotalCharges = TotalCharges + RowTotalCharges;
Session.Add("TotalPages", TotalPages.ToString());
Session.Add("TotalCharges", TotalCharges.ToString());
}
if (e.Row.RowType == DataControlRowType.Footer)
{
e.Row.Cells[4].Text = "Batches Count: " + gv1.Rows.Count.ToString();
e.Row.Cells[5].Text = Session["TotalPages"].ToString();
e.Row.Cells[6].Text = Session["TotalCharges"].ToString();
}
}

findcontrol does not find dynamically created control in rowUpdating eventhandler

I implemten ITemplate to dynamically create a Template field
TemplateField isReqField = new TemplateField();
isReqField.HeaderText = "Lizenz anfordern";
isReqField.ItemTemplate = new GridViewTemplate(DataControlRowType.DataRow, DataControlRowState.Normal, "isRequested", "bool");
isReqField.EditItemTemplate = new GridViewTemplate(DataControlRowType.DataRow, DataControlRowState.Edit, "isRequested", "bool");
gvLicence.Columns.Add(isReqField);
I implement InstantiateIn
public void InstantiateIn(System.Web.UI.Control container)
{
...
CheckBox ckRequest = new CheckBox();
ckRequest.ID = "ckRequest";
ckRequest.DataBinding += new EventHandler(this.CkIsRequested_DataBinding);
container.Controls.Add(ckRequest);
...
}
with the DataBinding Handler
private void CkIsRequested_DataBinding(Object sender, EventArgs e)
{
CheckBox ckRequest = (CheckBox)sender;
GridViewRow row = (GridViewRow)ckRequest.NamingContainer;
ckRequest.Checked = (bool)DataBinder.Eval(row.DataItem, columnName);
}
But then in the RowUpdating Handler I cannot find my checkBox Control with the FindControl Method:
protected void gvLicence_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
CheckBox chb = (CheckBox)gvLicence.Rows[e.RowIndex].FindControl("ckRequest");
bool requestValue = chb.Checked;
It throws an Exeption because gvLicence.Rows[e.RowIndex].FindControl("ckRequest") is null.
Many thanks for your attention and help.

find a control by id from Dynamically added Template field in GridView

Hi i added template field dynamically to gridview by implementing ITemplate interface.
The template field contains some controls like label and textboxes. how do i get these controls in row databound event.
I am not able to get when i do gridviewrow.findcontrol("id") as i do normally when we add templatefield from aspx page.
The way i added template field is like this
public class CustomGridViewColumn : ITemplate
{
ListItemType _liType;
string _columnName;
public CustomGridViewColumn(ListItemType type, string column)
{
_liType = type;
_columnName = column;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_liType)
{
case ListItemType.Header:
Label lblHeader = new Label();
lblHeader.Text = _columnName;
container.Controls.Add(lblHeader);
break;
case ListItemType.Item:
Label lblItem = new Label();
lblItem.DataBinding += new EventHandler(lbl_DataBinding);
lblItem.ID = "lbl" + _columnName;
lblItem.ClientIDMode = ClientIDMode.Predictable;
container.Controls.Add(lblItem);
DropDownList ddl = new DropDownList();
ddl.DataBinding += new EventHandler(ddl_DataBinding);
ddl.ID = "ddl" + _columnName;
ddl.Visible = false;
container.Controls.Add(ddl);
break;
}
}
}
Now i want access the label and dropdown which i have added using this code.
when i do gridviewrow.findcontrol("id") i am not getting them.
Can any one please help me.
I am geeting when i go through all the rows and try to find but
i have a check box in a row when i select it all labels should diappear and ddls dhould appear
for this i am using the follwoing code.
protected void chkEdit_CheckedChanged(object sender, EventArgs e)
{
CheckBox chkEditTest = (CheckBox)sender;
GridViewRow grow = (GridViewRow)chkEditTest.NamingContainer;
DropDownList ddl = (DropDownList)grow.FindControl("ddl");
Label lbl= (Label)grow.FindControl("lbl");
}
when i do this i am not able to get the controls.
it seems like controls are disapppearing on postback..
This is what I came up with and I can able to get the control reference in the code behind.
public class CustomGridViewColumn : ITemplate
{
ListItemType _liType; string _columnName;
public CustomGridViewColumn(ListItemType type, string column)
{
_liType = type;
_columnName = column;
}
void ITemplate.InstantiateIn(Control container)
{
switch (_liType)
{
case ListItemType.Header:
Label lblHeader = new Label();
lblHeader.Text = _columnName;
container.Controls.Add(lblHeader);
break;
case ListItemType.Item:
Label lblItem = new Label();
lblItem.DataBinding += new EventHandler(lblItem_DataBinding);
lblItem.ID = "lbl" + _columnName;
lblItem.ClientIDMode = ClientIDMode.Predictable;
container.Controls.Add(lblItem);
DropDownList ddl = new DropDownList();
ddl.DataBinding += new EventHandler(ddl_DataBinding);
ddl.ID = "ddl" + _columnName;
ddl.Visible = false;
ddl.DataSource = new string[] { "Hello", "World" };
container.Controls.Add(ddl);
break;
}
}
void ddl_DataBinding(object sender, EventArgs e)
{
}
void lblItem_DataBinding(object sender, EventArgs e)
{
}
}
protected void Page_Load(object sender, EventArgs e)
{
DataTable dt = new DataTable();
dt.Columns.Add("Name");
DataRow oItem = dt.NewRow();
oItem[0] = "Deepu";
dt.Rows.Add(oItem);
oItem = dt.NewRow();
oItem[0] = "MI";
dt.Rows.Add(oItem);
GridView gv = new GridView();
gv.ID = "myGridView";
gv.AutoGenerateColumns = false;
BoundField nameColumn = new BoundField();
nameColumn.DataField = "Name";
nameColumn.HeaderText = "Name";
gv.Columns.Add(nameColumn);
TemplateField TmpCol = new TemplateField();
TmpCol.HeaderText = "Template Column";
gv.Columns.Add(TmpCol);
TmpCol.ItemTemplate = new CustomGridViewColumn(ListItemType.Item, "TEST");
gv.DataSource = dt;
gv.DataBind();
Form.Controls.Add(gv);
}
protected void Button1_Click(object sender, EventArgs e)
{
GridView gv = Form.FindControl("myGridView") as GridView;
foreach (GridViewRow item in gv.Rows)
{
var ddl = item.FindControl("ddlTest") as DropDownList;
if (ddl != null)
{
ddl.Visible = true;
}
var lbl = item.FindControl("lbl") as Label;
if (lbl != null)
{
lbl.Text = "hello";
}
}
}
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
</form>
Thanks
Deepu
Can you try using row index of GRIDVIEW control
var rowIndex = int.Parse(e.CommandArgument)
GridView1.Rows[rowIndex].FindControl("id")
Also refer
http://forums.asp.net/t/998368.aspx/1
http://www.codeproject.com/Articles/12021/Accessing-the-different-controls-inside-a-GridView
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridviewrow.aspx
Thanks
Deepu

asp.net - GridView dynamic footer row creation problem

I am able to create BoundFields and Footer-rows dynamically like this in my GridView:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
CreateGridView();
}
}
private void CreateGridView()
{
GridView1.Columns.Clear();
DataTable dataTable = Book.GetBooksDataSet().Tables[0];
CommandField cf = new CommandField();
cf.ShowEditButton = true;
GridView1.Columns.Add(cf);
int colCount = 1;
foreach (DataColumn c in dataTable.Columns)
{
BoundField boundField = new BoundField();
boundField.DataField = c.ColumnName;
boundField.HeaderText = c.ColumnName;
//boundField.FooterText = "---";
if (colCount == 3 || colCount == 5)
{
boundField.ReadOnly = true;
}
GridView1.Columns.Add(boundField);
colCount++;
}
GridView1.ShowFooter = true;
GridView1.DataSource = dataTable;
GridView1.DataBind();
GridViewRow footerRow = GridView1.FooterRow;
Button b = new Button();
b.Text = "Add New";
int i = 0;
footerRow.Cells[i].Controls.Add(b);
foreach (DataColumn c in dataTable.Columns)
{
++i;
TextBox tb = new TextBox();
footerRow.Cells[i].Controls.Add(tb);
}
}
....................................
....................................
....................................
}
But the problem is, when I click the "Add New" - button, it disappears instantly. And, also I am unable to add any event handler to it. Or intercept its actions like this:
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
int index = Convert.ToInt32(e.CommandArgument);
if (e.CommandName == "Edit")
{
GridView1.EditIndex = index;
GridViewRow selectedRow = ((GridView)e.CommandSource).Rows[index];
//We can get cell data like this
string id = selectedRow.Cells[1].Text;
string isbn = selectedRow.Cells[2].Text;
//This is necessary to GridView to be showed up.
CreateGridView();
}
else if (e.CommandName == "Update")
{
LinkButton updateButton = (LinkButton)e.CommandSource;
DataControlFieldCell dcfc = (DataControlFieldCell)updateButton.Parent;
GridViewRow gvr = (GridViewRow)dcfc.Parent;
//The update...................
//Update grid-data to database
UpdateDataInTheDatabase(gvr.Cells[1].Controls);
//Grid goes back to normal
GridView1.EditIndex = -1;
//This is necessary to GridView to be showed up.
CreateGridView();
}
}
One more thing, I have seen some solutions that suggests to handle the GridView's rowBound event. But I need to do it from within Page_load event handler, or in, GridView1_RowCommand event handler.
Dynamically created controls mus be re-created on every postback. Your "Add New" button causes a postback so the dynamically created footer disappears. Is there a reason this grid has to be created dynamically? From the code you posted it appears that you could do this in markup instead. If not, you'll have to re-create the dynamic controls on every postback.
Edited to add:
I played with this a little bit and what's below works in that the grid doesn't disappear and events are handled, but it doesn't actually do anything. Hope this helps.
Markup:
<p><asp:Literal ID="Literal1" runat="server" /></p>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false"
OnRowCommand="GridView1_RowCommand"
OnRowEditing="GridView1_RowEditing"/>
Code:
protected void Page_Load(object sender, EventArgs e)
{
BindGridView();
}
private DataTable GetBooksDataTable()
{
var dt = new DataTable();
dt.Columns.Add("ID", typeof(int));
dt.Columns.Add("Title", typeof(string));
dt.Columns.Add("Author", typeof(string));
for (int index = 0; index < 10; index++)
{
dt.Rows.Add(index, "Title" + index, "Author" + index);
}
return dt;
}
private void BindGridView()
{
var dt = GetBooksDataTable();
GridView1.Columns.Clear();
GridView1.ShowFooter = true;
var cf = new CommandField();
cf.HeaderText = "Action";
cf.ShowEditButton = true;
GridView1.Columns.Add(cf);
for (int index = 0; index < dt.Columns.Count; index++)
{
var boundField = new BoundField();
boundField.DataField = dt.Columns[index].ColumnName;
boundField.HeaderText = dt.Columns[index].ColumnName;
GridView1.Columns.Add(boundField);
}
GridView1.DataSource = dt;
GridView1.DataBind();
var footer = GridView1.FooterRow;
var b = new LinkButton();
b.Text = "Add New";
b.CommandName = "Add New";
footer.Cells[0].Controls.Add(b);
for (int index = 1; index < dt.Columns.Count + 1; index++)
{
var tb = new TextBox();
footer.Cells[index].Controls.Add(tb);
}
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
Literal1.Text = e.CommandName;
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
Literal1.Text = "Editing row index " + e.NewEditIndex.ToString();
}
Move your code from Page_Load to Page_Init. Things added in the Page_Load last only for the lifecycle of one postback.
You'd then be able to add eventhandlers, intercept events etc.

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