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Exporting RadGridView Asynchronously Preserving Its Visual Settings

Product Version Product Author Last modified
2016.2.608 RadGridView for WinForms Hristo Merdjanov June 21, 2016

Problem

RadGridView provides async exporting capabilities out of the box. However, due to the background threads we are using and the target framework against which our assemblies are built (.NET 4.0) we are not exporting the visual settings with the existing async API.

Solution

Luckily in .NET 4.5 Microsoft introduced the async methods accompanied by the await statement. Essentially this allows heavy work to be done without freezing the UI. By definition the new async methods do not run on a separate thread so we should not worry about cross thread exceptions. The following MSDN article provides detailed information: Asynchronous Programming with Async and Await.

Requirements

.NET 4.5 and UI for WinForms Q2 2015 (version 2015.2.623) or later.

We are going to use the newly introduced async functionality and export RadGridView asynchronously preserving all of its visual settings.

The picture below compares the Excel output with the grid in our application

radgridview-async

We will start the exporting process in the Click event handler of a RadButton. Since only async methods can be awaited, we need to mark our event handler as async. The actual export job will be also separated in its own async method. If you prefer you can instead use a lambda expression.

private async void radButton1_Click(object sender, EventArgs e)
{  
    await this.ExportGridVisuallyAsync();
}
private async Task ExportGridVisuallyAsync()
{
    Action job = new Action(this.ExportData);
    Task task = new Task(job);
    task.Start();
    await task;
}
private void ExportData()
{
    GridViewSpreadExport spreadExporter = new GridViewSpreadExport(this.radGridView1);
    spreadExporter.ExportVisualSettings = true;
    SpreadExportRenderer exportRenderer = new SpreadExportRenderer();
    spreadExporter.RunExport(@"..\..\exported-grid.xlsx", exportRenderer);
    RadMessageBox.Show("Export completed!");
}

Private Async Sub RadButton1_Click(sender As Object, e As EventArgs) Handles radButton1.Click
    Await Me.ExportGridVisuallyAsync()
End Sub
Private Async Function ExportGridVisuallyAsync() As Task
    Dim job As New Action(AddressOf Me.ExportData)
    Dim task As New Task(job)
    task.Start()
    Await task
End Function
Private Sub ExportData()
    Dim spreadExporter As New GridViewSpreadExport(Me.radGridView1)
    spreadExporter.ExportVisualSettings = True
    Dim exportRenderer As New SpreadExportRenderer()
    spreadExporter.RunExport("..\..\exported-grid.xlsx", exportRenderer)
    RadMessageBox.Show("Export completed!")
End Sub

The GridViewSpreadExport object defines a CellFormatting event and if needed you can subscribe to it and perform custom styling only to the Excel cells: GridViewSpreadExport | Events.

You can download a VB and C# project from the following link.

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