Cross-thread operation not valid: Control ‘dataGridView1’

Hi Mates,

I would to get all some data from sharePoint site using win form for UI.

InFact i am getting expected output if not using Asynch, await(multi threading) but when i apply multi threading it thows below error.

Cross-thread operation not valid: Control 'dataGridView1' accessed from a thread other than the thread it was created on.

yes i am using data table to add columns, calling a function to add columns.

Actual Code from here :

private String lists() // function here for actual logic here to get data.

{

var st = "";

if (Global.sctx != null)

{

Web web = Global.sctx.Web;

Global.sctx.Load(web, w => w.Lists);

Global.sctx.ExecuteQuery();

ListCollection listcoll = web.Lists;

Global.sctx.Load(listcoll);

Global.sctx.ExecuteQuery();

addcolumnsdatatable(); // here calling method for add coulunms.

foreach (List list in listcoll)

{

var dr = dt.NewRow();

st = list.Title;

dr["List Names"] = list.Title;

dt.Rows.Add(dr);

}

dataGridView1.DataSource = dt; // error here with Cross-thread operation not valid

}

return string.Empty;

}

private async void button3_Click(object sender, EventArgs e)

{

Task getliststhread = new Task(lists);

getliststhread.Start();

label10.Text = "Loading lists please wait...";

var getLists = await getliststhread;

label10.Text = "List Exported Grid View Sucessfully...";

}

void addcolumnsdatatable() //adding columns here

{

dt.Columns.Add("List Names", typeof(String));

}

kindly help me here with peaice if script where to add, what should i add going forward to avoid errors.

thanks In Advance.

3 Replies

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Amit Gupta7y ago
Yeah! That was one of the solution too but using controls under threading will have a little degradation in performance. Good luck
0
Murali Kris7y ago
Hi Amit,

Thank you for reply, as you said avoiding controls is one of the sollution, but not in this case.
Infact issue is fixed with help of setting property with false.

Control.CheckForIllegalCrossThreadCalls = false;

above line code resloved the issue.

Thank you...
0
Amit Gupta7y ago
When using threading, try to avoid uaing the controls that are created in the application. Issue can be resolved by just setting the datasource outside the await function.
0