Dynamically created rows disappear from Gridviews on update/delete - asp.net

Situation: I have several Gridviews on one page, and each Gridview has a dynamically created row to display the totals at the bottom. In each case, the totals row is created on a RowDataBound event. The strategy that I am using is like the one provided by Mike Dugan on his Blog.
The following is the code for one of the GridViews, but the others all do something very simular.
protected void gvWorkerHours_RowDataBound(object sender, GridViewRowEventArgs e)
{
// Keep running total of hours.
if (e.Row.RowType == DataControlRowType.DataRow)
{
totalBillableHours += Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Hours"));
}
if (e.Row.RowType == DataControlRowType.Footer)
{
int numColumns = gvWorkerHours.Columns.Count;
int hoursIndex = 4; //5th column, 0-based
int rowIndex = gvWorkerHours.Rows.Count + 1;
CreateTotalRow((Table)e.Row.Parent, rowIndex, totalBillableHours, hoursIndex, numColumns);
}
}
private void CreateTotalRow(Table table, int rowIndex, double totalValue, int totalIndex, int numColumns)
{
TableCell[] cells = new TableCell[numColumns];
for (int i = 0; i < numColumns; i++)
{
TableCell cell = new TableCell();
Label label = new Label();
label.Font.Bold = true;
if (i == 0)
{
label.Text = "Total";
}
else if (i == totalIndex)
{
label.Text = totalValue.ToString();
}
else
{
label.Text = "";
}
cell.Controls.Add(label);
cells[i] = cell;
}
GridViewRow row = new GridViewRow(-1, -1, DataControlRowType.DataRow, DataControlRowState.Normal);
row.Cells.AddRange(cells);
table.Rows.AddAt(rowIndex, row);
}
Problem: If a user clicks on an edit/delete command for any row on any of these Gridviews, it will make the totals row disappear for all other Gridviews. As I understand, this is because a PostBack is occurring, however the RowDataBound events will not occur for the other GridViews, rather they will just reload their data from the ViewState, which does not contain the totals.
Failed attempts at solving: I cannot simply call DataBind on each of the GridView during a PostBack, because that will prevent the update/delete from occurring. Although the RowCreated event will occur for the GridViews during a PostBack, this event in not sufficient because the GridViews will not have data bound and will throw an exception when I try to calculate the total. Disabling the ViewState for these GridViews seems like a solution, however there will be a lot of data to reload each time a user clicks a command. Manually saving my data to the ViewState also seems like a solution, but there does not seem to be a simple way to have the GridViews retrieve this custom data on a PostBack.
Is there any way to actually achieve what I am trying to do with ASP.NET? It seems like a simple requirement to have a totals row at the bottom of each GridView.
Thanks in advance for any help.

What if you try creating the dynamic row using the gridView.OnPreRender event instead of the gridView.RowDataBound event. This way your data you need to calculate your dynaimic row results is available but the html has not been sent to the web browser yet. Please post some more code so we can provide more insight into fixing your issue.

As recommended, I tried putting the code to create the totals row in the PreRender event rather than the RowDataBound event. This seemed to work, except that it broke all of the commands for the GridView that it was used on. It appears that manually changing the GridView disrupts its automatic behavior.
protected void gvWorkerHours_PreRender(object sender, EventArgs e)
{
double total = 0;
int numColumns = gvWorkerHours.Columns.Count;
int hoursIndex = 4; //5th column, 0-based
int rowIndex = gvWorkerHours.Rows.Count + 1;
foreach (GridViewRow row in gvWorkerHours.Rows)
{
if (row.RowType == DataControlRowType.DataRow)
{
Label label = (Label)row.FindControl("lblHours");
total += Convert.ToDouble(label.Text);
}
}
CreateTotalRow((Table)gvWorkerHours.Rows[0].Parent, rowIndex, total, hoursIndex, numColumns);
}

OK, the way I ended up solving this was with JQuery. If anybody else is facing a similar problem, remember that the totals must be calculated when the DOM is ready, as well as at the end of any postback. To handle the postback situation, you can just call the Javascript on the client using ScriptManager.RegisterStartupScript().
Again, I had four GridViews in my circumstance, but I'll just show the JQuery code for one of them:
$(document).ready(function () {
setTotals();
});
function setTotals() {
var totalHours = getBillableHoursTotal();
if (isNaN(totalHours)) totalHours = '...editing';
$('#spanBillableHoursTotal').html(totalHours);
//... etc.
}
function getBillableHoursTotal() {
var total = 0.0;
var rows = $('table[id*="_gvWorkerHours"] tr.RegularRows');
$(rows).each(function () {
total = total + parseFloat($(this).children('td').children('span[id*="lblHours"]').html());
});
return total;
}
And for the C# on the code behind:
protected void Page_Load(object sender, EventArgs e)
{
// ... preceeding Page Load code
if (IsPostBack)
{
ScriptManager.RegisterStartupScript(this, this.GetType(), "?", "setTotals()", true);
}
}

Related

Loop through a gridview to replace the cell value

I want to loop through a gridview cell values and replace any value which has an asterisk like 3*,4*, ** etc to change like 3(underline), 4 underline and 8 (underline)..so basically i want to remove the asterisk and underline the inetger..Please guide me on this...thank you
You can loop trough every row and cell trough this:
foreach(DataGridViewRow gridRow in myGridview.Rows)
{
for(int i = 0; i < myGridview.Columns.Count; i++)
{
if(gridRow.Cells[i].Text.Contains('*'))
{
//Do your thing
gridRow.Cells[i].Text=gridRow.Cells[i].Text.Replace(#"*", "");
gridRow.Cells[i].Style.Font = new Font("Ariel", 8, FontStyle.Underline);
}
}
}
You can achieved this by using RowDataBound Event.. No need to loop
GridView.RowDataBound Event
The following example demonstrates how to use the RowDataBound event to modify the value of a field in the data source before it is displayed in a GridView control.
void CustomersGridView_RowDataBound(Object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
// Display the company name in italics.
e.Row.Cells[1].Text = "<i>" + e.Row.Cells[1].Text + "</i>";
}
}

Get control which is generated on runtime

am creating some TextBoxes by backend on a text change event, Like this :
protected void txtHowMany_TextChanged(object sender, EventArgs e)
{
int totalSections = Convert.ToInt32(txtHowMany.Text.Trim());
for (int i = 1; i <= totalSections; i++)
{
TextBox tbx = new TextBox();
tbx.Text = "";
tbx.ID = "section" + i;
tbx.Style.Add("width", "90%");
tdSectionsAdd.Controls.Add(tbx);
}
trSectionsName.Visible = true;
}
The auto post back is true for txtHowMany, so when I enter a number, it generates the textboxes and add it to table division
Now the problem is, I am trying to get text from generated textboxes like this :
protected void btnSave_click(object sender, EventArgs e)
{
int numbersOfSectionsToSave = 1;
int sectionsToSave =Convert.ToInt32(txtHowMany.Text.Trim());
for (int i = 1; i < sectionsToSave; i++)
{
Sections section = new Sections();
section.CourseId = result;
section.OrganizationId = course.OrganizationId;
foreach (Control c in tdSectionsAdd.Controls)
{
if (c.GetType() == typeof(TextBox))
{
TextBox txtBox = (TextBox)c;
string id = "section" + i;
if (txtBox.ID == id)
{
section.Name = txtBox.Text.Trim();
}
}
}
string name = Request.Form["section1"];
section.CreatedBy = "Admin";
section.CreationDate = DateTime.Now;
section.ModifiedBy = "Admin";
section.ModificationDate = DateTime.Now;
numbersOfSectionsToSave += section.SaveSection();
}
But its showing 0 count for the controls in tdSectionsAdd , The controls are added before I am trying to access them, but still it shows no controls in td.
Please help, How can I get these textboxes?
Thanks!
You need to add them in each postback. Store the totalSections variable in ViewState so you can add them i page load also:
protected void AddTextBoxes()
{
int totalSections;
if (int.TryParse(Convert.ToString(ViewState["TotalSections"]), out totalSections)
{
for (int i = 1; i <= totalSections; i++)
{
TextBox tbx = new TextBox();
tbx.Text = "";
tbx.ID = "section" + i;
tbx.Style.Add("width", "90%");
tdSectionsAdd.Controls.Add(tbx);
}
trSectionsName.Visible = true;
}
}
protected void txtHowMany_TextChanged(object sender, EventArgs e)
{
ViewState["TotalSections"] = Convert.ToInt32(txtHowMany.Text.Trim());
tdSectionsAdd.Controls.Clear();
AddTextBoxes();
}
protected void Page_Load(object sender, EventArgs e)
{
AddTextBoxes();
}
Dynamic Created controls "Disappear" on postback, if they are not "recreated" in the Page_Init of that page.
Only if they are created in the page_init will the page's viewstate get updated with their information.
Long Explantion:
When we perform a postback (or partial postback) we want to be able to access those controls (or at least the values the user put into them).
We know that the data is in the viewstate, but ASP.NET doesn’t really know which control a ViewState item belongs to. It only knows to match a viewstate item and a control through the same index (e.g. Matches item n in the viewstate tree to item n in the control tree). Therefore in order to get the dynamic controls' data, we need to re-create the controls each time the page is postbacked.
BUT in order for this to work, we need to re-create the controls in the Page_Init function NOT in the Page_Load.
Why? Because when the ViewState is created it needs all the controls to already exist.
This is taken from MSDN, as you can see the viewstate is loaded AFTER the init but before the page load.
TL;DR Call the function that creates the dynamic controls in the page_init and you should be able to see all the values the user entered when the page postbacks
A few links on this issue:
http://forums.asp.net/t/1186195.aspx/1
ASP.NET - Dynamic controls created in Page_Pre_init() or Page_Init() or Page_Load()
Option 2:
I should note: If the controls all had unique Ids and you're not interested in re-creating them again every postback - you could always look for them in the Request Object.
The Request.Form is a NameValueCollection that holds the values of all the controls that were part of the form, just search it for whatever you're looking for

How to get row count inside Gridview label

I have an ItemTemplate Label inside Gridview which I haven't bound with any DataField.
I have userId as one of the columns of GridView.
Based on the userId column, I want to get total no of assets acquired by the User. The totalNo doesn't exists in the database. I have to manually fire a query and get total no of row counts.
Now, how to put this rowCount for each user inside GridView?
Any ideas?
I have tried onRowDataBound and FindControl, but how do I get rowIndex for that particular user?
You add an event function for the DataBound on your GridView and when its render the Header you can change it like:
protected void grdView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
for (int i = 0; i < e.Row.Cells.Count; i++)
{
e.Row.Cells[i].Text = "Custom header";
}
}
}

Dropdownlist in repeater control

I have 3 dropdownlist which will have set of values from the database. In my page, I have different controls. I was planning to add this dropdownlist in a repeater control.
When a user selects a value, the value will be saved to the database, either by a save button inside the control or automatically.
Could you please let me know if this is possible? If yes, any code that can be shared would be helpful.
Yes, it's possible. The trick is that the DataSource for the dropdownlists are separate than the DataSource of the Repeater.
Here's the sample code:
protected void cmdSave_Click(object sender, EventArgs e)
{
foreach (RepeaterItem ri in GeneralRepeater.Items)
{
switch (ri.ItemType)
{
case ListItemType.Item:
case ListItemType.AlternatingItem:
DropDownList GetValue = (DropDownList)ri.FindControl("GeneralDDL");
var sSelectedValue = GetValue.SelectedValue;
for (int index = 0; index <= PocDiagnoses.MAX_DIAGNOSIS; index++)
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foreach (RepeaterItem ri1 in GeneralRepeater.Items)
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int iItemIndex = ri1.ItemIndex;
DropDownList myDDL = (DropDownList)GeneralRepeater.Items[index].FindControl("GeneralDDL");
FirstPlanOfCare.Diagnoses.Diagnoses[index] = new PatientDiagnosis(myDDL.SelectedValue, new SynergyOnSetDate(new System.DateTime(Year, Month, Day)), "01/02/2011"); //Insert Diagnosis Value
}
}
break;
}
}
//Create
Chart.AddPlanOfCare(FirstPlanOfCare);
}

creating dynamic control in asp.net

I'm creating a fileupload control on a linKbutton click event. First time it's creating the controls, but if I press the link button second time, it's not creating. What is the problem with that? The following is my code:
protected void LinkButton1_Click(object sender, EventArgs e)
{
newattach();
}
private void newattach()
{
int i;
for (i = 0; i < 2; i++)
{
count++;
FileUpload f1 = new FileUpload();
f1.ID = "fileupload" + count.ToString();
f1.Height = 34;
f1.Width = 212;
Panel1.Controls.Add(f1);
}
}
and count is a static variable. Please help.
When you create controls dynamically with ASP.NET you need to recreate the control every time you post back, generally you recreate the control on Page_Load. That is most likely the cause of your problem.

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