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Cross thread Exception

Cross thread Exception

D L

13y2kVisual Basic .NET

I don't understand why I get a cross threading exception on this. Can someone plz explain?

Thread1 = new Thread(()=>UpdateLabel(ref label1));

Thread1.Start();

void UpdateLabel(ref Label _label1)

{

lock(_label1)

{

_label1.Text = "Hello World";

}

}

I thought that would make it a resource shared between the GUI thread and Thread1.

2 Replies

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Santhosh Kumar Jayaraman13y ago
Accepted answer
sample application code.

I created new winform app. Added one label Label1 in UI.

In code behind

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();

Thread Thread1 = new Thread(() => UpdateLabel(ref label1));
Thread1.Start();

}

void UpdateLabel(ref Label _label1)
{
if (this.label1.InvokeRequired)
{
this.BeginInvoke(new MethodInvoker(() => UpdateLabel(ref label1)));
}
else
{
this.label1.Text = "test";
}
}

}

}

it is working fine
Santhosh Kumar Jayaraman13y ago
rewrite the updateLabel method like below.

void UpdateLabel(ref Label _label1)
{
if (this.label1.InvokeRequired)
{

this.BeginInvoke(new MethodInvoker(() => UpdateLabel(ref label1)));
}
else
{

this.label1.Text = "test";
}
}