In the last column of my asp .net GridView I have an image and a checkbox. I want to check if that checkbox is checked, for all rows. I am getting null reference exception at if cause maybe chk is null. any help?
try
{
foreach (GridViewRow row in grdSurveyDetails.Rows)
{
int index = row.Cells.Count - 1;
CheckBox chk = row.Cells[index].Controls[1] as CheckBox;
int rowIndex = row.RowIndex;
if (chk.Checked)
{
ClientScript.RegisterClientScriptBlock(typeof(Page), "alert", "<script>alert("+rowIndex+" is checked!);</script>");
}
}
}
catch (Exception)
{
throw;
}
I'm assuming that you populate the gridview via code, so that you always have an image and checkbox in that last cell. If that's the case, something that come to my mind is that you may be accessing the header row which does not have the checkbox in there.
Nonetheless, could you try doing the null check in there, something like
if (chk?.Checked)
That ? is doing a null check for you. If it's null, then do not do anything with that row.
NB: if the cell doesn't always contains image and checkbox, then use caution as you may have a checkbox in that cell which wasn't at index 1 (ie: you may consider using #Rojalin Sahoo approach to search for checkbox explicitly)
You can check all checked like this
Lets say you have
Aspx
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="chkRow" runat="server" />
</ItemTemplate>
</asp:TemplateField>
Then in
Code Behind
foreach (GridViewRow row in grdSurveyDetails.Rows)
{
if (row.RowType == DataControlRowType.DataRow)
{
int index = row.Cells.Count - 1;
CheckBox chkRow = (row.Cells[index].FindControl("chkRow") as CheckBox);
if (chkRow.Checked)
{
//do something
}
}
}
Please look at this complete example
Here
Related
This is a .aspx page.
I currently have this:
foreach (GridViewRow gvr in gvShows.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
if (((CheckBox) gvr.FindControl("cbSelect")).Checked)
{
string dataSource = gvr.Cells[1].Text;
}
}
}
Which works if the column is visible.
However, the gridView column is now hidden but I still need to capture its value.
How would I go about converting the above code to get the dataSource value which is in a hidden column?
I have a GridView which has multiple rows, on each row I have a CheckBox and a HiddenField. On button click I want to check if the CheckBox is checked and if it is I want to take the value of the HiddenField for that row. Each HiddenField on each row has a different value. User could check multiple CheckBoxes so I need to be able to pull the value of each HiddenField.
Any help will be really appreciate it.
Thank you
Loop through each row in the grid, check if the checkbox is checked and if it is, grab the value of the hidden field.
foreach (GridViewRow row in grdView.Rows)
{
if((row.FindControl("chkBoxId") as CheckBox).Checked)
{
string hiddenFieldValue = (row.FindControl("hiddenFieldId") as HiddenField).Value;
}
}
Where chkBoxId is the ID property of your checkbox on the page and hiddenFieldId is the ID of the hiddenfield control on your page.
Possible duplicates.
How to get values of CheckBoxes inside a gridview that are checked using asp .net
Get the id of selected checkboxes in gridview (Asp.net) c#
How to get the value in the gridview which the checkbox is checked?
One of the answer in above links :
foreach(Gridviewrow gvr in Gridview1.Rows)
{
if(((CheckBox)gvr.findcontrol("CheckBox1")).Checked == true)
{
//Get hidden field value here.
}
}
You can use a code like this:
protected void BtnMybutton_click( Object sender, EventArgs e)
{
Button Mybutton = (Button) sender;
GridViewRow row = (GridViewRow) MyButton.NamingContainer;
CheckBox ChkTest = (CheckBox) row.FindControl("ChkTest");
HidenFiekd HdfValue = (HidenField) row.FindControl("HdfValue");
if(ChkTest.Checked)
{
Console.WriteLine(HdfValues.Value);
}
}
I have datagridview with checkbox column, and the checkbox within the column can be checked or unchecked with external checkbox. It works fine while selecting all the columns and saving the data in database. But, when I unchecked the checkbox in the datagridview with external checkbox and again select the single checkbox within the datagridview, it again takes the rowindex of all the checkbox within the column.
if (chkbranches.Checked == true)
{
foreach (DataGridViewRow dr in gridviewholiday.Rows)
{
dr.Cells[0].Value = true;
}
for (int i = 0; i < gridviewholiday.Rows.Count; i++)
{
rowindex = i;
list.add(rowindex);//to put the rowindex in array list
}
}
else if (chkbranches.Checked == false)
{
foreach (DataGridViewRow dr in gridviewholiday.Rows)
{
dr.Cells[0].Value = false;
gridviewholiday.Refresh();
gridviewholiday.ClearSelection();
list.Clear();
}
}
Why do you loop twice if chkbranches is checked? Can't you add items to the list within the first foreach? And in the loop for unchecking, why do you refresh, and clear both controls each time? Probably only needed once.
And as mentioned, this isn't doing anything about single checks. If you're expecting it to, that seems to be the problem.
Not quite sure what your attempting to do, but I have something similar with a button that deletes all the checked rows. I use a template field like so for the check box:
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="cbSelector" runat="server" />
</ItemTemplate>
</asp:TemplateField>
Then for the Delete button code behind I do:
protected void btnDeleteChecked_Click(object sender, EventArgs e)
{
foreach (GridViewRow row in gridOrders.Rows)
{
CheckBox cb = (CheckBox)row.FindControl("cbSelector");
if ((null != cb) && cb.Checked)
{
uint id = Convert.ToUInt32(gridOrders.DataKeys[row.RowIndex].Value);
gInvoiceDB.DeleteInvoice(id, true);
}
}
}
I have an ASP.NET 2.0 (C#) web app, and in it I have a gridview that gets its data from an oracle database.
I want to know how to check if the gridview is empty, and the do something.
I have already tried:
if(GridView.Rows.Count == 0)
{
// Do Something
}
but it doesn't work...
Any ideas?
Thank you.
Your code should work. But only after GridView.DataBind() has been called. Generally I don't check the GridView it's self, but the datasource of the grid view.
DataTable data = DAL.getdata();
if (data.Rows.Count == 0)
{
ShowEmptyData();
}
else
{
Grid.DataSource = dt;
Grid.DataBind();
}
This doesn't work since the GridView is data bound and is going to fetch the actual data at a later time while rendering the page. You should check this by directly querying the data binding source of the gridview (see if the actual list that's grid view bound to is empty or not).
If you just want to display something when it's empty, you should use <EmptyDataTemplate> in your markup:
<asp:GridView runat="server">
<EmptyDataTemplate>The grid is empty</EmptyDataTemplate>
</asp:GridView>
I agree with the other responses. I want to add little information, you should get rows.count after databind method :
int rowCount = GridView.Rows.Count; // returns zero
GridView.DataBind();
rowCount = GridView.Rows.Count; // returns actual row count
If you're using databinding, the the row count of the datasource not the count on the grid itself.
Its very easy: Hope it works for you.. :)
Use event of GridView DataBound: which fires after data is bound.
protected void GridView1_DataBound(object sender, EventArgs e)
{
int rowCount = GridView1.Rows.Count;
if (rowCount == 0)
{
GridView1.Visible = false;
}
else
{
GridView1.Visible = true;
}
}
First create a helper class.
public static class GridViewExtensions
{
public static IEnumerable<GridViewRow> AsEnumerable(this GridView grid)
{
foreach (GridViewRow row in grid.Rows)
{
yield return row;
}
}
public static bool IsEmpty(this GridView grid)
{
return !grid.AsEnumerable().Any(t => t.RowType == DataControlRowType.DataRow);
}
}
Then just call IsEmpty
GridView1.IsEmpty()
In case you've configured your GV to automatically fetch the data from DB, then you may add the following line as the first statement of your GV in Source mode:
<EmptyDataTemplate>No data found.</EmptyDataTemplate>
And then continue with the normal code in your GV.
Based on answers already, GridView.Rows.Count is not enough on its own, depending on the nature of your GridView, especially if it's a dynamic gv, which in most cases it is, plus you have to factor in Paginating, Headers and Footers, which alter the row count.
I use a simple method to tell me ...
//checks if a gridview has any actual rows of data (not just blank rows filled in by the Load
protected bool gvNoData(GridView gv)
{
int wsDataRow = 0;
foreach (GridViewRow gvRow in gv.Rows)
if (gvRow.RowType == DataControlRowType.DataRow)
{
HiddenField hf = (HiddenField)gvRow.FindControl("hfStudentID");
if (hf != null)
if (hf.Value.ToString().Length > 0)
wsDataRow +=1;
}
//if a count was generated then there are data rows, otherwise the rows are blank or nonexistant
if (wsDataRow > 0) return false;
else return true;
}
So running something like this will tell you if the Rows are really "
"DATA" rows, or empty or nothing!
Obviously in my case I have a HiddenField to tell me if the GridViewRow is an actual data row, as I prefill my gridview with blank rows (for my purposes) and some datarows.
However, a simpler version to check based on DataRow vs HeaderRow, etc...
foreach (GridViewRow gvRow in myGridView.Rows)
if (gvRow.RowType == DataControlRowType.DataRow)
{
//do what you need
}
I hope this helps.
In short, there is no GridView.IsEmpty() function unfortunately, unless you enumerate one as shown below.
I am creating a gridView that allows adding new rows by adding the controls necessary for the insert into the FooterTemplate, but when the ObjectDataSource has no records, I add a dummy row as the FooterTemplate is only displayed when there is data.
How can I hide this dummy row? I have tried setting e.row.visible = false on RowDataBound but the row is still visible.
You could handle the gridview's databound event and hide the dummy row. (Don't forget to assign the event property in the aspx code):
protected void GridView1_DataBound(object sender, EventArgs e)
{
if (GridView1.Rows.Count == 1)
GridView1.Rows[0].Visible = false;
}
Please try the following
protected void GridView1_DataBound(object sender, EventArgs e)
{
GridView1.Rows[0].Visible = false;
}
I think this is what you need:
<asp:GridView ID="grid" runat="server" AutoGenerateColumns="false" ShowFooter="true" OnRowDataBound="OnRowDataBound">
<Columns>
<asp:TemplateField HeaderText="headertext">
<ItemTemplate>
itemtext
</ItemTemplate>
<FooterTemplate>
insert controls
</FooterTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
and the codebehind:
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Attributes["style"] = "display:none";
}
}
But I do not understand why you are adding your "insert controls" to the footer instead of placing them below the grid.
Maybe try:
e.Row.Height = Unit.Pixel(0);
This isnt the right answer but it might work in the meantime until you get the right answer.
Maybe use CSS to set display none?!
This is the incorrect usage of the GridView control. The GridView control has a special InsertRow which is where your controls should go.
GridView has a special property to access Footer Row, named "FooterRow"
Then, you cold try yourGrid.FooterRow.Visible = false;
I did this on a previous job, but since you can add rows, I always had it visible in the footer row. To make it so that the grid shows up, I bound an empty row of the type that is normally bound
dim row as Datarow = table.NewRow()
table.AddRow(row)
gridView.DataSource = table
gridView.Databind()
then it has all the columns and then you need. You can access the footer by pulling this:
'this will get the footer no matter how many rows there are in the grid.
Dim footer as Control = gridView.Controls(0).Controls(gridView.Controls(0).Controls.Count -1)
then to access any of the controls in the footer you would go and do a:
Dim cntl as Control = footer.FindControl(<Insert Control Name Here>)
I'd assume you'd be able to do a:
footer.Visible = false
to make the footer row invisible.
I hope this helps!
Edit I just figured out what you said. I basically delete the row when I add a new one, but to do this you need to check to see if there are any other rows, and if there are, check to see if there are values in it.
To delete the dummy row do something like this:
If mTable.Rows.Count = 1 AndAlso mTable.Rows(0)(<first column to check for null value>) Is DBNull.Value AndAlso mTable.Rows(0)(<second column>) Is DBNull.Value AndAlso mTable.Rows(0)(<thrid column>) Is DBNull.Value Then
mTable.Rows.Remove(mTable.Rows(0))
End If
mTable.Rows.Add(row)
gridView.Datasource = mTable
gridView.Databind()
Why are you not using the EmptyDataTemplate? It seems to work great even though I have only been using it for a couple days...
You should use DataKeyNames in your GridView:
<asp:GridView ID="GridView1" runat="server" DataKeyNames="FooID">
And then retrieve it on your code:
GridView1.DataKeys[0].Value.ToString()
Where "0" is the number of the row you want to get the "FooID"
To make it visible, just use:
Gridview.Rows.Item(i).Attributes.Add("style", "display:block")
And to make it invisible
Gridview.Rows.Item(i).Attributes.Add("style", "display:none")
If you do not want to display data when the column/row is null:
if (!String.IsNullOrEmpty(item.DataName))
{
e.Row.Visible = false;
}
It can easily be done by SQL
USE YourdatabaseName select * from TableName where Column_Name <> ''