Forms Data Controls :: Gridview HeaderTemplate Access Dropdownlist In Code Behind?
Jan 24, 2011
I have a dropdownlist in a headertemplate but I can't seem to access it in the code behind to work with the onselectedindexchanged event. I want to change the data that is shown on the event but can't access the control.
I have an imagebutton control in the column HeaderTemplate of a gridview and want to know how to reference the imagebutton so I can add an attribute to it programmatically. Following is the code for my gridview control:
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I can reference the checkbox control correctly with CheckBox chkbox = GridView1.FindControl("chkSelected") as CheckBox;However, I have tried the following code for the imagebutton but I get the error message Object reference not set to an instance of an object.:
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Or is the OnInit event handler the right place to reference the control?
I'm dynamically adding a DropDownList to the GridView in edit mode and I have set the TextBox Visibility to False. In edit mode I can see the DropDownList and I'm able to select an Item from the DropDownList but not able to access the SelectedValue in RowUpdating Event. How to get the selectedvalue of this DropDownList?
Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound If e.Row.RowType = DataControlRowType.DataRow And (e.Row.RowState And DataControlRowState.Edit) > 0 Then Dim ddl as DropDownList FillStateList(ddl) e.Row.Cells(4).Controls.Add(ddl)
ddl is the DropDownList that is added dynamically. And the default Textbox that is in the Edit mode is set to invisible. So there are actually two controls in the same cell in edit mode(TextBox is invisible).
If I use the above statement I'm getting NullException.This is Probably because its a BoundField. Is there a way I can access the DropDownList 'ddl' SelectedValue?
I need to generate a GridView and inside of one of the cells insert a DropDownList.
The GridView is a list of the users of the web application.The DropDownList is a list of roles of the web aplication.
The GridView is to be a table with the diferent users, diferent columns with various information, the last cell should have a DropDownList with the roles, the role which the user of the line belongs to, should be visible!
I am trying to bind the datasource of a ddl which is located inside the EditTemplate of a TemplateField.When is the best time to bind this datasource (after loading grid, before editing, ? (Note: I must do this in code behind).I am currently trying to bind it on the edit command:
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The issue is that the list retrieved from the LoadLists method is null when passing to the LoadList method where the datasource is bound.
i have gride view and there are three dropDownList in every row in grideview,i want get selected value from every DropDownList,and pass the values to storeprocedure in sql,I dont know how pass value every row, to store procedure,and StoreProcedure get 3 value.
GridViewDetails uses templatefields. In edittemplate I put a button called "ButtonUpdateAdjustAmount" with OnClick="Update_AdjustAmount" in the EditItemTemplate for the "Amt to be Adj" column. There is also a textbox. My user's should be able to edit the textbox, but I also want the ability to click the button and the textbox populated with the correct calculated value. The formula varies based on the "code" column which is a dropdownlist called "DropListCode".
I am fairly new to asp.net, vb, etc...so forgive my code writing. Eventually I need to also put the same functionality on the insertrow for my gridview. But first wanted to get the edit one working. I am using templatefields for all columns and the FooterTemplate to perform the Insert New Detail Line.
I can get the functionality to work for the first data row and only if I take out the If code.SelectedValue = ... line and leave 1 static formula. However that isn't going to work. If DropListCode.SelectedValue is DNR then AdjAmt should be ((q_ordered - q_received) * cost). If DropListCode. SelectedValue is OV then AdjAmt should be (RKNumber * cost). If DropListCode.SelectedValue is NB the AdjAmt should be ((q_received - q_ordered) * cost). If DropListCode.SelectedValue is DAM then AdjAmt should be (RKNumber * cost)
Probably a fairly simple one. Just need to know how I can make reference to controls in the HeaderTemplate of a DataList. I've got a form in there that I need to get the data from.
On my formview I have a drop down list that is populated with the names of the files in a certain directory. This works fine, but when the drop down list selected value is bound to the database field I get the following error :
'ImageFileDropDownList' has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value
I have setup other drop down lists in the same formview populated from SqlDataSources and these all work fine. I can see perhaps why this is an issue because I have not specified a DataValueField or a DataTextField for this drop down that is populated in code (whereas I can for the SQL bound ones) because I'm not sure what these settings would be.
I need to have a "blank" option as well so that the field does not default to the first value in the list.
My code (I have stripped out some meaningless controls) :
I have a datagrid "dgParents" and inside this datagrid I have another datagrid "dgChildren".
In dgChildren I have three dropdownlist drp1, drp2, drp3.
I have a button"Save"
I am able to populate data.
Now User selects any value from dropdownlist of dgChildren and click button "Save".
I have a function in code behind for button click here I want to access the values of drpdownlists that are in dgChildren so that I can save in thesevalues in db.
I'm not able to acess the vlues of dropdownlists that are in dgChildren.
I tries findcontrol and controls etc but didnt work.
I'll really appreciate any help for sample code/tutorial/.
I select a item from gridView and trying to show/update/delete in From view. In Form View I am using the dropdownlist filling it in Code behind. Then i bound the list. But the problem is it is not showing the slected value. Here is the code
I am using an event calendar control (not a MS control) and I am trying to access a LinkButton inside this control's HeaderTemplate. Below is what I have tried so far. I get the familiar "Object reference not set to an instance of an object" error. Does anyone has an alternate way to get this control? I need to change the visibility property of it.
Let me try to explain my situation. I have a database table which contains, among other things, a boolean column called PermissionSlipRequired. I have a repeater on my page, and before each row in the database is shown in the repeater, I want to use my code behind to check the value of PermissionSlipRequired. Based on whether the value of PermissionSlipRequired is true or false, I want to change the text of a literal within the repeater. That's a real mouthful; hopefully some markup and code will clarify. Here's my repeater:
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Here is what I've been able to come up with for my code behind. Needless to say, this code doesn't work.
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As a former PHP user who is trying to migrate to asp.net.
Scenario: I am creating a custom gridview control which has a custom CheckBoxTemplateField column (deriving from TemplateField class). This template field column has custom Checkboxheadertemplate (implementing ITemplate) and CheckboxItemTemplate (also implementing ITemplate). In InstantiateIn method of both templates (header as well as Item template), I am adding a checkbox control which has Autopostback = true.
My requirement is: I want to mark all the values in the binding column of datasource if checkbox in headertemplate is checked. I dont want to mark only rows visible on grid. I WANT TO MARK ALL ROWS IN DATASOURCE. I want to do this in _CheckedChanged event of checkbox in header template.
Problem I am facing: When I check/uncheck the checkbox in header, it postbacks. so in OnCheckedChanged event, gridview's datasource is null. Secondly, in any event of gridview, I could access only those rows of datasource for which corresponding rows are visible in gridview through Gridviewrow.DataItem property. But I want to set it for all rows in datasource.
My problem i am facing is that i do not know if it's possible to access a single field in my case sold from the following code.
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What i want to do is have the checkbox true if the value of sold = yes and false if the value = no I have the checkbox ready on the asp.net side but just need for the checkbox to recognise the datafield, sold, and do and if check statement, is this possible if not i will work around it.