Reputation: 17298
i try to start multi Thread but i can not it returns to me error: Cross-thread operation not valid: 'listBox1' thread was created to control outside access from another thread was.
MyCodes:
public DataTable dTable;
public DataTable dtRowsCount;
Thread t1;
ThreadStart ts1;
void ExcelToSql()
{
// SelectDataFromExcel();
ts1 = new ThreadStart(SelectDataFromExcel);
t1 = new Thread(ts1);
t1.Start();
}
void SelectDataFromExcel()
{
string connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Source\Addresses.xlsx;Extended Properties=""Excel 12.0;HDR=YES;""";
OleDbConnection excelConnection = new OleDbConnection(connectionString);
string[] Sheets = new string[] { "Sayfa1"};
excelConnection.Open(); // This code will open excel file.
OleDbCommand dbCommand;
OleDbDataAdapter dataAdapter;
// progressBar1.Minimum = 1;
foreach (var sheet in Sheets)
{
dbCommand = new OleDbCommand("select * From[" + sheet + "$]", excelConnection);
//progressBar1.Maximum = CountRowsExcel(sheet).Rows.Count;
// progressBar2.Value = i + 1;
System.Threading.Thread.Sleep(1000);
**listBox1.Items.Add("Tablo ismi: "+sheet.ToUpper()+"Satır Adeti: "+CountRowsExcel(sheet).Rows.Count.ToString()+" ");**
dataAdapter = new OleDbDataAdapter(dbCommand);
dTable = new DataTable();
dataAdapter.Fill(dTable);
dTable.TableName = sheet.ToUpper();
dTable.Dispose();
dataAdapter.Dispose();
dbCommand.Dispose();
ArrangedDataList(dTable);
FillSqlTable(dTable, dTable.TableName);
}
excelConnection.Close();
excelConnection.Dispose();
}
Upvotes: 2
Views: 4354
Reputation: 457167
You cannot update a UI component from a non-UI thread. Use TaskScheduler.FromCurrentSynchronizationContext
to marshal the call to the UI thread.
Upvotes: 3
Reputation: 52528
The thread in background is not allowed to access the UI components.
In multithreaded forms, I include code like this:
private delegate void InvokeAction();
private void DoUI(InvokeAction call) {
if (IsDisposed) {
return;
}
if (InvokeRequired) {
try {
Invoke(call);
} catch (InvalidOperationException) {
// Handle error
}
} else {
call();
}
}
Then from my background thread I can code like this:
// Stuff in other thread
myVar = GetFromDb();
DoUI(() => {
// Access UI components here
listBox1.Items.Add(myVar);
});
// More other thread
Upvotes: 5
Reputation: 2119
A control created in the UI thread cannot be accessed in another thread in normal fashion. Please create a delegate and invoke the delegate using control.Invoke.
The method sample provided below can be used to enable visibility on a button regardless of the thread context you are in.
private void EnableButtonVisibility( Button btn, bool enable)
{
if ( !btn.InvokeRequired )
{
btn.Visible = enable;
}
else
{
btn.Invoke( new EnableButtonVisibilityHandler( EnableButtonVisibility ), btn, enable );
}
}
delegate void EnableButtonVisibilityHandler( Button btn, bool enable);
Upvotes: 4