Running Gridview without freezing PC

[Robert Gouin]

I am currently using a good old fashioned
 gvDispensing.MasterGridViewTemplate.LoadFrom(openRS(tSQL))
command to load a record set into a grid view.

Some of the data I am working with has 80/150 thousand lines, and when I open the form, it takes over 2 minutes to load the grid view using the code below.

gvDispensing.MasterGridViewTemplate.AllowAddNewRow = False
        gvDispensing.MasterGridViewTemplate.ShowRowHeaderColumn = False
        gvDispensing.MasterGridViewTemplate.AutoGenerateColumns = True
        gvDispensing.MasterGridViewTemplate.BestFitColumns()

        gvDispensing.GridElement.BeginUpdate()

        tSQL = "Crazy Multi Join Query Here"
        gvDispensing.MasterGridViewTemplate.LoadFrom(openRS(tSQL))

Is there anyway to open the form, and attach a progress bar to this loading process so that the user knows that something is happening?

[Julian Benkov]

Hi Robert Gouin,

For this scenario you can override your DataReader object and add a Notify event. Here is a simple implementation of SqlDataReader and logic for ProgressBar update:

public class MySqlDataReader : SqlDataReader
{
    public event EventHandler Notify;

    public override bool Read()
    {
        if (this.Notify != null)
        {
            this.Notify(this, new EventArgs());
        }

        return base.Read();

    }
}

public partial class Form1 : Form
{
    private int recordCount = 0;
    private int currentCount = 0;

    public Form1()
    {
        InitializeComponent();

        //Return Count of records using
        SqlCommand command = new SqlCommand();
        command.CommandText = "SELECT COUNT('Test')";
        this.recordCount = (int)command.ExecuteScalar();

        MySqlDataReader reader = new MySqlDataReader();
        reader.Notify += new EventHandler(reader_Notify);
        this.radGridView1.MasterGridViewTemplate.LoadFrom(reader);
    }

    void reader_Notify(object sender, EventArgs e)
    {
        currentCount++;
        this.progressBar1.Value = (int)((this.currentCount / (double)this.recordCount) * 100);
    }
}

Sincerely yours,

Julian Benkov
the Telerik team

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[Robert Gouin]

Wow, thank you so much, currently as a MS patch all I did was make the load a background working and have a waiting bar just keep going and going until it was done with no progress indication what-so-ever.  It reminded me of the old VB installer when the bar really meant nothing but it was a moving bar lol.

[Robert Gouin]

By any chance do you have the VB.net equivalent to this code?

[Julian Benkov]

Hi Robert Gouin,

You can use our online converter to do this for you. We have done this for your convenience, so here is the VB version:

Public Class MySqlDataReader
   Inherits SqlDataReader

   Public Event Notify As EventHandler

   Public Overloads Overrides Function Read() As Boolean
       RaiseEvent Notify(Me, New EventArgs())

       Return MyBase.Read()
   End Function

End Class


Public Partial Class Form1
   Inherits Form


   Private recordCount As Integer = 0
   Private currentCount As Integer = 0


   Public Sub New()

       InitializeComponent()

       'Return Count of records using
       Dim command As New SqlCommand()
       command.CommandText = "SELECT COUNT('Test')"
       Me.recordCount = CInt(command.ExecuteScalar())

       Dim reader As New MySqlDataReader()
       AddHandler reader.Notify, AddressOf reader_Notify
       Me.radGridView1.MasterGridViewTemplate.LoadFrom(reader)
   End Sub

   Private Sub reader_Notify(ByVal sender As Object, ByVal e As EventArgs)
       currentCount += 1
       Me.progressBar1.Value = CInt(((Me.currentCount / CDbl(Me.recordCount)) * 100))
   End Sub

End Class

Regards,
Julian Benkov
the Telerik team

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[luke johnson]

I am using an object to populate my GridView Datasource, is there a simple way of using the status strip/progress bar to indicate that the data is loading?

[Julian Benkov]

Hi Luke,

There is no way to handle this scenario in RadGridView control. You can implement this functionality when you prepare your data source object. Additionally, in the DataBindingComplete event of RadGridView you can perform the last step (for example the last 10%) of the work completion.

If you have other questions, do not hesitate to contact me again. 

Regards,
Julian Benkov
the Telerik team

[Yaroslav]

Hi, I'm interested also on showing a progess bar for some of the data loading process I have as some of them take some time to finish. I typically use binding sources of the datasource of the grids or either directly setup the datasource and datamember fields of the grid. Tried the recommende approach but without success.

It will be usefull if a code snippet is provided to use it as base...thanks!

[Julian Benkov]

Hi Yaroslav,

This functionality closely depends on your binding object and its loading mechanism. Please share with us code snippets of the logic that you have to load your data source object. This will allow us to assist you further.

Thank you for your cooperation. I am looking forward to your reply.

All the best,

Julian Benkov
the Telerik team

[Yaroslav]

Hi, I believe a code snippet will not help too much as the scenario can be different each time. I usually setup all the enviroment coding and what I usually do is:

1. create dataset and assign an existing dataset from my existing model
2. create binding source, set datasource to previously created dataset and set the needed datamemeber
3. create a table adapter with a method to, either call a stored procedure or execute a query
4. create a gridview and binding it to the binding source created on the 2nd step

On user request I call the method on the table adapter and then gridview.refresh()

Hope it helps.

[Julian Benkov]

Hello Yaroslav,

The DataSet, DataTable and DbAdapter types do not support this functionality. The only possible solution in this situation is to use segmented version of Fill method of your adapter and update progressbar based on this segmentation. Here is a description of this method from ADO.NET:

//
// Summary:
//     Adds or refreshes rows in a System.Data.DataTable to match those in the data
//     source starting at the specified record and retrieving up to the specified
//     maximum number of records.
//
// Parameters:
//   startRecord:
//     The zero-based record number to start with.
//
//   maxRecords:
//     The maximum number of records to retrieve.
//
//   dataTables:
//     The System.Data.DataTable objects to fill from the data source.
//
// Returns:
//     The number of rows successfully added to or refreshed in the System.Data.DataTable.
//     This value does not include rows affected by statements that do not return
//     rows.
public int Fill(int startRecord, int maxRecords, params DataTable[] dataTables);

I hope this helps.

All the best,
Julian Benkov
the Telerik team