Can any one explain to me what the use of "InsertVisible" property of BoundField in a GridView is and at what conditions we should use it? I have seen the description on msdn.com but I am not able to understand exactly.
Thanks in advance.
The GridView control is not designed for inserting data. Thus, this explanation is more applicable to a DetailsView or a FormView.
When you put a databound control into "insert mode", it turns all of the BoundFields into user input controls (TextBoxs, CheckBoxs, etc) by default. InsertVisible allows you to change this as follows:
InsertVisible = true: A user-input control will be generated. This allows a user to enter a value for that field into your datasource.
InsertVisible = false: A user input control is not to be generated, thus the user is not given the opportunity to enter a value.
This is especially useful if you plan to programatically fill out that field (with an auto-generated ID or some calculated value).
Here is the MSDN article as a reference (I realize you mention that you read the article, this is just for the sake of completeness).
Related
I have several Gridviews and Repeaters bound to SqlDataSources using stored procedures. I am trying to implement sorting functionality into some of these but am having a hard time finding concrete instructions and/or examples of what is required on the SqlDataSource side to generate the ORDER BY's needed. Particularly, I do not understand the point of having a SortParameterName property in the SqlDataSource if all it does is manually connect to an ORDER BY clause in the stored procedure. Why define it as such if it is just another parameter in the SelectParameters list like any other, but just so happens to be connected to the ORDER BY clause? When I run the code example below, I am told there are too many arguments specified (obviously, the extra SortParams argument). Do I really need to alter my stored procedures and add "ORDER BY #SortParams" clauses to the end of the existing queries to make this work? I feel like I am missing something.
SqlDataSourceInLine.SelectParameters.Clear()
SqlDataSourceInLine.SelectCommandType = SqlDataSourceCommandType.StoredProcedure
SqlDataSourceInLine.SelectCommand = "ApproverGetApproved"
SqlDataSourceInLine.SelectParameters.Add("CompanyID", ConfigurationManager.AppSettings("Temp_CompanyID"))
SqlDataSourceInLine.SelectParameters.Add("SortParams", "EmpName DESC")
SqlDataSourceInLine.DataSourceMode = SqlDataSourceMode.DataSet
SqlDataSourceInLine.SortParameterName = "SortParams"
Dim dv As DataView = SqlDataSourceInLine.Select(DataSourceSelectArguments.Empty
Any clarification would be appreciated!
I was just trying to figure out how to use the SortParameterName and found this question. After doing some more search I think I have now found the correct answer.
Microsofts page Sorting Data with Data Source Controls says as follows (my emphasis):
The parameter identified by the SortParameterName property is passed to the ObjectDataSource control's SelectMethod or passed as part of the parameter collection to the SqlDataSource control's SelectCommand. The ObjectDataSource control can use the information passed to it in the sort parameter to return the data in sorted order. For the SqlDataSource control, you must supply the name of a stored procedure that can take the sort parameter and return the sorted data, because you cannot pass a parameter as part of an ORDER BY clause.
This indicates that the answer given by Icarus is not correct.
My conclusion is that when the SortParameterName property is set (in combination with an appropriate stored procedure) the Gridview will not do the sorting itself, but will let the datasource do a so called Custom Sorting, which for example would be the necessary way to sort if Custom Paging is used.
Update:
I have now used it in my own programming and confirmed that my conclusion was correct.
I've never used the SortParamter in the past, but what I gather from the documentation is that the purpose of this parameter is to allow you to get the results sorted in the way you want them in case the stored procedure does not do it already. Other than that, you don't need to use it for anything. A GridView whose datasource is of type SqlDataSource already implements sorting out of the box. You simply need to set the AllowSorting property to True and the SortExpression on every column.
Example:
<asp:GridView ID=" productsGridView" Runat="server"
DataSourceID="SqlproductDataSource" AutoGenerateColumns="False"
AllowSorting="True" >
<Columns>
<asp:BoundField HeaderText="Product"
DataField="ProductName" SortExpression="ProductName">
</asp:BoundField>
...
Nothing is required on the SqlDataSource. You need to implement the Sorting event for the Gridview and something else for the repeaters since they don't have sorting built in. What you could do (if you have small datasets coming back) is to use ViewState and store your DataTable of results and then utilize the DataView and the sorting capability of that, then bind the Repeaters/GridViews to the sorted DataView. You still have to keep track of the SortDirection and SortParameter within ViewState, regardless.
I have a scenario where I want to put four identical Gridviews on the same page. (They will be on different tabs in an Ajax TabControl.) They show the same source data, but there are four corresponding groups of source data in a common underlying table. So I want to show Group 1 on Tab 1, Group 2 on Tab 2, etc. These Gridviews contain complicated controls, so I would prefer to use the same data source for all of them to avoid unnecessary repetition. The Insert and Update commands are completely identical.
So in theory I could build the Select command in such a way that I could filter the data based on the GridView that is binding to the SQLDataSource. The problem is that if I use the same SQLDataSource for all the Gridviews, I cannot find a way to have each GridView tell the SQLDataSource which one is calling it. I am thinking maybe this is not possible, because the SQLDataSource binds first before it knows what is binding to it, but I'm not sure. Can anyone think of a way to do this?
You can change the parameter value dynamically using OnSelecting event of SQLDataSource. This can be done in server side code.
Create a property which holds your current gridview unique key, which is causing SQLDataSource to fetch data from SQL database.
Assign this property unique gridview key on DataBinding event of gridview.
Based on this property change the parameter in OnSelecting event of SQLDataSource.
Let me know if I am missing something.
Is there a way to iteratively reference an ASP.NET control based on it's name pattern? Perhaps by a "pointer" or something?
What I have are a large set of comboboxes (each with an associated DropDownList and TextBox control). The DropDownList always has an item selected by default, but the use may wish to submit a NULL value. I come up with the following code to handle three cases: NULL, Existing Item, New Item.
'TextBoxControl & DropDownListControl should iteratively reference their
' respective TextBox & DropDownList controls by the actual control name
If StrComp(TextBoxControl.Text, DropDownListControl.SelectedItem.ToString) = 0 Then
'When an Existing Item is selected, Do Something
ElseIf Not TextBoxControl.Text = "" Then
'When a New Item is entered, Validate & Do Something
Else
'When NULL, Do Something
End If
The problem is, with so many comboboxes, I could easily end up with hundreds of lines of code. I wish to handle this in a more dynamic way, but I do not know if it is possible to reference controls in this way. Say I wanted to reference all the TextBox Controls and DropDownList Controls, respectively.
I can do string formatting with a given naming pattern to generate a name ID for any of the controls because they are all named with the same pattern. For example by attaching a specific suffix, say "_tb" for TextBox Controls and "_ddl" for DropDownList Controls:
Left(item.SelectedItem.ToString, item.SelectedItem.ToString.Length - 3) + "_tb"
Can this sort of thing be done in VB? Ultimately, my goal is to take the value entered/selected by the user, if any, and send it to a stored procedure on SQL Server for insertion into the database.
Yes. Write your code inside of a function having parameters for the textbox and the dropdown, and then write the function in terms of those two parameters. Then you simply call that function for every set instead of copy/pasting code everywhere.
Don't attempt choosing things by name. That's fragile and imposes machine requirements on a field that'd designed for human consumption.
I am not sure if the samething that applies VBA will apply to your situation, but I had the same issue and was able to use:
Me.MultiPage1.Pages(1).Controls("ref" & i + 1).Value
where controls encompasses all controls on the userform ("Me"). So if the controls in your program conform to a consecutive naming structure it is easy handle if the above applies vb.net
When I attach a Site Map data source type to a site map control, I specify an ID for the data source.
Where in the code (or config files) is that ID associated with the corresponding Web.sitemap file?
Is it that there can be only one site map data source and the ID is actually redundant information?
Cheers.
DataSourceID is used when the source data is provided by another control of type DataSourceControl in the page, for instance a SqlDataSource control.
DataSource is used to provide the data directly. You should use either, but not both.
Look the DataSource is a control ,you can find it in the Data section of your tool box(ex:sqldatasource,objectdatasource,...etc).
You can set the datasource of your control(gridview for example)through one of two ways:
The first one is to drag the specific datasource control from the
toolbox and drop it in your page,then set the DataSourceID property
of your control by the id of the datasource control you has dragged.
The second one is through the code behind, you can set the
DataSource property of your control then call the DataBind().
You can't use both of the two ways at the same time. but you can solve this problem.if you wanna to use the both (each one under specific case or condition)then first you should set the other one by null before you can use the other one.
like this:
gv1.DataSource = null;
gv1.DataSourceID = ObjectDataSource1.ID;
gv1.DataBind();
and vice versa .
I'm looking for the easiest way to bind data from a SqlDataSource to textboxes dropped in Visual Studio 2008.
For example, I have 4 textboxes currently that have Address, City, State, Zip. I also have a SqlDataSource on the page fetching the ID of the record and selecting those 4 fields based on ID.
How am I able to quickly bind each box to those particular fields selected? I would think this would be really straight forward - but seems it's not. Seems like the answer is funneled towards having to create a GridView or some type of control.
Be gentle...I'm a nub :)
In general you are correct, if you want to use databinding you'll need to use an appropriate control. For this example I'd suggest using a FormView - it is designed to display the results from a single database record and uses templates, meaning you'll have complete control over the output. This article is probably a good place to start: FormView Control: Step by Step.
To read the values bound to the FormView in the code-behind class you would need to create an event handler for the FormView's DataBound event. In that event handler you would reference the controls programmatically via FindControl, like so:
Dim myLabel As Label = CType(FormViewID.FindControl("id"), Label)
Here, id would be the ID of the Label whose value you were interested in. Once you have a reference to the Label you can get its value using myLabel.Text.