many time we populate UI with data from DB in the form load and that is why form gets freeze for few second. so i just want to know how can i load data asynchronously and populate UI in form load as a result my form will not freeze and also will be responsive but i don't want to use background worker class. please help me with sample code which can solve my problem.
thanks
Here is a well commented example code:
// This method can be called on Form_Load, Button_Click, etc.
private void LoadData()
{
// Start a thread to load data asynchronously.
Thread loadDataThread = new Thread(LoadDataAsync);
loadDataThread.Start();
}
// This method is called asynchronously
private void LoadDataAsync()
{
DataSet ds = new DataSet();
// ... get data from connection
// Since this method is executed from another thread than the main thread (AKA UI thread),
// Any logic that tried to manipulate UI from this thread, must go into BeginInvoke() call.
// By using BeginInvoke() we state that this code needs to be executed on UI thread.
// Check if this code is executed on some other thread than UI thread
if (InvokeRequired) // In this example, this will return `true`.
{
BeginInvoke(new Action(() =>
{
PopulateUI(ds);
}));
}
}
private void PopulateUI(DataSet ds)
{
// Populate UI Controls with data from DataSet ds.
}
Command.BeginExecuteReader()
may serves your need for reading purposes.
Here is Sample Code for this method.
You can call Application.DoEvents() while waiting for response to keep your window responsive.
@Downvoter, please be courteous enough to let everyone know why you felt the need to downvote this one.
Have a look at this article. http://aspadvice.com/blogs/azamsharp/archive/2007/04/05/Executing-a-Query-Asynchronously-in-.NET-2.0.aspx
It still uses Background worker. Honestly, I can't think of an alternative solution to this this other than threading your application to execute queries and bind returned results. If you do decide to use threads, than i suggest you take a look at this article about thread-pooling for asynchronous execution: http://www.yoda.arachsys.com/csharp/threads/threadpool.shtml
Your best course of action is to use another thread. You can use one straight from the thread pool by calling ThreadPool.QueueUserWorkItem.
private void OnFormLoad()
{
ThreadPool.QueueUserWorkItem(() => GetSqlData());
}
private object GetSqlData()
{
using (var connection = new SqlCeConnection("ConnectionString"))
{
using(var command = new SqlCeCommand())
{
command.Connection = connection;
command.CommandText = "SELECT * FROM tbl_hello";
command.ExecuteReader();
while (command.ExecuteReader().Read())
{
//Put data somewhere
}
}
}
}
