c# async calls UI not responding

Question

This is my requirement:

On a button click I need to get the data from database and populate in a datagridview, for which I'm using a function. As the retrieval may take a long time and I want to use the UI meanwhile, I want this function to run in a separate thread. For this, I'm using async callback. But between the begininvoke() and endinvoke() function. I'm not writing any code (I don't know what to write to make the UI respond).

The datagridview is getting populated correctly but the UI is blocked when I'm trying to access it when the function is retrieving the data.

Answer 1

First of all, i should create asynccallback function in the UI form itself, not in middle level which is, in my case , DataMgr. Also, i should add the last two parameters for begininvoke function with appropriate values where i have passed null values. It should be

MethodDelegate dlgt = new MethodDelegate(DataMgr.countIssuingEntities);
 TempValueHolder tmp = new TempValueHolder();
 AsyncCallback cb = new AsyncCallback(MyAsyncCallBack);
  IAsyncResult ar = dlgt.BeginInvoke(issueGroupId, element.ControlType, (EvaluatingEntityCombo.SelectedItem as CIQHydCore.RefData.RefDataInfo).Id, (IssuingEntityCombo.SelectedItem as CIQHydCore.RefData.RefDataInfo).Id, str1, str2,**cb,dlgt**);

and in MyAsyncCallBack function we need to populate the datgridview with the retrieved values from the end