Questions on UI for WinForms Forum

1 answer

391 views

Null reference exception when setting the DataSource of a ChildGridViewTemplate

Hi,

I am using RadControls for WinForms Q3 2009 SP1

I created two UserControls each one has a RadGridView in it. i.e. AListControl and BListControl.
Each RadGridView is bounded to a DataSource which list objects of type A and B.
When I use the controls separately (as I should) it works fine.

Now I try to use the RadGridView of object B as a ChildGridViewTemplate of A.
To avoid recreating the whole grid definition I use the following in AListControl constructor:

    
            public AListControl() 
        
            { 
        
               InitializeComponent(); 
        
               // Create dummy BListControl 
        
               BListControl bListControl = new BListControl(); 
        
               // Add the B's MasterGridViewTemplate to A as a ChildGridViewTemplates 
        
               this.radGridViewA.MasterGridViewTemplate.ChildGridViewTemplates.Add( 
        
                  bListControl.radGridViewB.MasterGridViewTemplate); 
        
               // Add the relation 
        
               GridViewRelation relation = new GridViewRelation(this.radGridViewA.MasterGridViewTemplate); 
        
               relation.ChildTemplate = bListControl.radGridViewB.MasterGridViewTemplate; 
        
               relation.RelationName = "A2B"; 
        
               relation.ParentColumnNames.Add("Id"); 
        
               relation.ChildColumnNames.Add("B.AId"); 
        
               this.radGridViewA.Relations.Add(relation); 
        
            }

I also added a menu item in the context menu that sets the DataSource of bListControl.radGridViewB.MasterGridViewTemplate.
When I set the DataSource the application fails with the exception "Object reference not set to an instance of an object."

This is the callstack I got:

     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTraverser.IsRowVisible(Telerik.WinControls.UI.GridViewRowInfo rowInfo) + 0x32 bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTraverser.MoveForward() + 0x95 bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.UpdateScrollbars(bool resetValue) + 0x165 bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.Update_OrderChanged(Telerik.WinControls.UI.GridUINotifyAction action, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x12c bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridTableElement.UpdateCore(Telerik.WinControls.UI.GridUINotifyAction action, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x74 bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.UI.GridViewTemplate.UpdateUI(Telerik.WinControls.UI.GridUINotifyAction action = SortingChanged, Telerik.WinControls.UI.GridViewRowInfo[] rowInfos) + 0x33f bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.InitializeSorting() + 0x109 bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.InitDataGrid() + 0x14e bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.Bind(object dataSource, string dataMember) + 0x32c bytes
     Telerik.WinControls.GridView.dll!Telerik.WinControls.Data.DataAccessComponent.DataSource.set(object value) + 0x65 bytes
>   InspectSims.exe!Inspector.AListControl.ShowBsClicked(object sender = {Telerik.WinControls.UI.RadMenuItem}, System.EventArgs e = {System.EventArgs}) Line 62 + 0x2b bytes   C#

Can you tell me if this is the correct way to do this, or if there is another way to do this ?

Regards,
Ami

GridView

answered on 07 Jul 2010

1 answer

108 views

Getting Cell Values in Radgrid - URGENT HELP RQD.

hi,

I have a radgridview.While clicking on the cells, I got the values in a radlabel as shown below.
But I got the error ,"Object reference not set to an instance of an object " when clicking on the gridview header or some other places in the radgridview.How can i avoid this error.

Private Sub RadGridView1_CellClick(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles RadGridView1.CellClick

RadLabel5.Text =

"Selected S.No :" & e.Row.Cells("serialno").Value & " - " & e.Row.Cells("name").Value.ToString

GridView

answered on 07 Jul 2010

1 answer

119 views

Regarding the Drag&drop in RadGridView

hi,telerik
we are developing the winform application in telerik control,we used the RadGridView to display the data to the user,we listed all the files that came from a folder,we want to drag an item from RadGridView to desktop(item means a row,it display the information for a file,for example ,filename,datetime,author),but it failed ,it can trigger any events,or drag a file from desktop to RadGridView,it also failed,we have set the AllowDrop=true;i don't know how to implement this function,could u pls help me implement this function, it's very important to our project.my email is feiying0803@163.com;Thanks for you help...

GridView

answered on 07 Jul 2010

3 answers

128 views

Autogeneratecolumns property ignored :(

Hi,

Having spent way too long on this, what has to be done to switch autogenerated columns OFF on the GridView? The property seems to be getting ignored, whether I set it in codebehind or in the propertymanager.

I've defined my columns through the collection in Vis Studio, and then call

SqlConnection cn = new SqlConnection(feedsSvr);
            cn.Open();
            SqlCommand cmd = new SqlCommand("ASP_GetDeltas", cn);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@FeedGUID", feedGUID);
            SqlDataReader dr = cmd.ExecuteReader();
            radGridView1.MasterGridViewTemplate.AutoGenerateColumns = false;
            radGridView1.MasterGridViewTemplate.LoadFrom(dr);

Thanks for your help!!

Paul

GridView

answered on 07 Jul 2010

4 answers

223 views

RadGridView Column Chooser and Context Menu

Do not work (?)

GridView

answered on 07 Jul 2010

2 answers

99 views

Retrieve SQL Auto ID

How can I retrieve the SQL Server Auto Increment ID when adding a record to the grid when binding source is a Table Data Adapter?

Anyone?

T.I.A.

GridView

answered on 07 Jul 2010

9 answers

388 views

Binding to Hierarchical Data Programmatically

I have setup a Hierarchical Grid programmatically basically following the example in the Documentation. Now I need to update some Cells in the ChildGridView programmatically and assumed I can update the cell info with the following:

    
            '-- The ChildGridView has already been populated with data  
        
            Dim cTemplate As GridViewTemplate = GridViewPricing.MasterGridViewTemplate.ChildGridViewTemplates(0)  
        
            'The following throws an error : 
        
            'Object reference not set to an instance of an object.  
        
            cTemplate.Rows(0).Cells(1).Value="somedata"

The above throws the Object reference not set to an instance of an object error. In fact accessing any of the Cells methods or properties throws the Object Not set to an instance of an object.

Any help greatly appreicated.

GridView

answered on 07 Jul 2010

1 answer

108 views

Making Ribbon/Toolbar Optional

Hi,
I'm evaluating your WinForms control suite and was wondering if I can build an application where the user can choose between having a ribbon or a menu/toolbar application window. If so, how can I switch between those modes programmatically? Some other control vendors just require to drop the ribbon control onto a standard form to make it a ribbon form. When I then hide the ribbon control and show the menu/toolbar, I'm basically back in standard (menu/toolbar) mode again. Is something like that possible using Telerik?

RibbonBar

answered on 06 Jul 2010

2 answers

574 views

DropDown or ComboBox for filtering a gridview

I have been looking all weekend for this solution but cant seem to figure it out. I have a sql database, very small and simple. It is basically is a support database for taking service requests. (just a training for myself) I have a database view that i'm using to bring the information into my winform project.

I'm trying to figure out the best way to filter a gridview using the dropdown.

1. Is it possible to populate a RadDropDownButton with the Technician Name items from a sql database and then filter the records in a gridview?
2. Is it better to use a combobox although the dropdown seems to look cooler?

So I have a radform, drop a raddropdown and a gridview on the form... I can get the gridview to display records, I can get a combobox to show the technicians but I can only get the dropdown to display the first technician.

I have not been able to get any of the dropdowns or combobox's to filter the gridview.. anybody have any simple solutions that I may be missing?

I have tried several different ways, one such as this:

    
            Public Class RadForm1  
        
                Private Sub RadForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load  
        
                    'TODO: This line of code loads data into the 'WODataset.WorkOrderMain' table. You can move, or remove it, as needed.  
        
                    Me.WorkOrderMainTableAdapter.Fill(Me.WODataset.WorkOrderMain)  
        
                    RadDropDownButton1.Items.Add(WODataset.WorkOrderMain.techFullNameColumn)  
        
                    RadComboBox1.Items.Add(WODataset.WorkOrderMain.techFullNameColumn)  
        
                End Sub 
        
            End Class