Unresponsiveness issue during Real-Time Updates in Winforms DataGridView

[DhivyaBharathi-SF3890]

.NET version

.Net 7.0

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No response

Issue description

In DataGridView, while updating the values like real-time updates, the demo becomes unresponsive. Without using the Refresh() method the values are not updated.

DataGrid_Refresh.zip

Steps to reproduce

1.Run the sample.
2.Click the Refresh button.

Observed Behavior:
The sample enters into the Not responding state

[lonitra]

@KlausLoeffelmann could you take an initial look at this?

[Zheng-Li01]

The issue can reproduce both .NET from 6.0 to 9.0 and .NET Framework 4.7.2 to 4.8.1 as below screenshot.

[LeafShi1]

This issue can be reproduced using the following simple code

 private void button1_Click(object sender, EventArgs e)
 {
     for (int i = 0; i < 100000; i++)
     {
         dataGridView1.Refresh();
     }
 }

WinFormsApp7.zip

[elachlan]

I don't think this is a bug. You are using thread.sleep in the UI thread. DataGridView.Refresh will trigger an invalidation of the whole gridview and repaint it. All of that will end up locking the UI thread.

It would be better to use a separate thread (via a background worker or similar) to report progress to the UI thread. BackgroundWorker.ReportProgress allows you to pass an object as well. Which can be your "progress" class.

[DhivyaBharathi-SF3890]

We have checked the background worker with our scenario, but it did not help and caused an exception. When we call DataGrid.Refresh for a specific record by passing in the BackgroundWorker.ReportProgress, it also throws an exception. If we call BackgroundWorker.ReportProgress for a certain limit of records, the value only updates for those records. Please find the sample demo in the attachment. Could you please take a look at that sample and suggest a proper way to achieve this?

DataGrid_Refresh.zip

[elachlan]

@DhivyaBharathi-SF3890 ObservableCollection is not threadsafe. You can't bind it on the UI thread and then create a separate thread and pass it to it afterwards.

I would avoid using datagrid and instead use a progress bar. Using the background worker report progress to change the progress percentage and some sort of text indicating the number of completed vs total (100/1000). Your dowork event needs to take in parameters, do work (reporting as you go), then return a result. You can't access things on the UI thread in doWork, This is why you pass parameters to it.