multithread to richtextbox

[zbcong]

hello
i put a richtextbox and a button on the winForm.when the button is clicked,it generate several threads to write to the richtextbox,the code snippet as following:
private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the richtextbox MULTITHREADINGL Y,any code snippet is appreciated.

thank you!

[Henrik Dahl]

By using Form.BeginInvok e.

Also in this case it could be an idea to read and understand the conceptual
foundation. The 3 series article on MSDN on multi threaded WindowsForms
programming could make a good beginning. When you've understood the concepts
you'll know that the richtextbox may only be used by the STA thread which
created it.
Best regards,

Henrik Dahl
"zbcong" <zb****@discuss ions.microsoft. com> wrote in message
news:79******** *************** ***********@mic rosoft.com...

hello
i put a richtextbox and a button on the winForm.when the button is clicked,it generate several threads to write to the richtextbox,the code
snippet as following:

private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the richtextbox MULTITHREADINGL Y,any code snippet is appreciated.
thank you!

[Shaival Trivedi]

your code is perfect it will run perfectly..

but still try this

delegate void rptdel();

private void rpt()

{

for(int i=0;i<3000;i++)

{

this.richTextBo x1.AppendText(" hello world");

}

}

private void button2_Click(o bject sender, System.EventArg s e)

{rptdel rp = new rptdel(rpt);
rp.BeginInvoke( null,null);
}
"zbcong" <zb****@discuss ions.microsoft. com> wrote in message
news:D7******** *************** ***********@mic rosoft.com...

hello
i put a richtextbox and a button on the winForm.when the button is clicked,it generate several threads to write to the richtextbox,the code
snippet as following:

private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the richtextbox MULTITHREADINGL Y,any code snippet is appreciated.
thank you!

"zbcong" <zb****@discuss ions.microsoft. com> wrote in message
news:79******** *************** ***********@mic rosoft.com... hello
i put a richtextbox and a button on the winForm.when the button is clicked,it generate several threads to write to the richtextbox,the code
snippet as following:

private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the richtextbox MULTITHREADINGL Y,any code snippet is appreciated.
thank you!

[Henrik Dahl]

You should also invoke EndInvoke().
Best regards,

Henrik Dahl

"Shaival Trivedi" <sh*****@gatewa ytechnolabs.com > wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

your code is perfect it will run perfectly..

but still try this

delegate void rptdel();

private void rpt()

{

for(int i=0;i<3000;i++)

{

this.richTextBo x1.AppendText(" hello world");

}

}

private void button2_Click(o bject sender, System.EventArg s e)

{rptdel rp = new rptdel(rpt);
rp.BeginInvoke( null,null);
}
"zbcong" <zb****@discuss ions.microsoft. com> wrote in message
news:D7******** *************** ***********@mic rosoft.com...

hello
i put a richtextbox and a button on the winForm.when the button is

clicked,it generate several threads to write to the richtextbox,the code
snippet as following:

private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the

richtextbox MULTITHREADINGL Y,any code snippet is appreciated.

thank you!

"zbcong" <zb****@discuss ions.microsoft. com> wrote in message
news:79******** *************** ***********@mic rosoft.com...

hello
i put a richtextbox and a button on the winForm.when the button is

clicked,it generate several threads to write to the richtextbox,the code
snippet as following:

private void btnSend_Click(o bject sender, System.EventArg s e)
{
for(int i=0;i<3;i++)
{
Thread thread =new Thread(new ThreadStart(rpt ));
thread.Start();
}
}

private void rpt()
{
this.richTextBo x1.AppendText(" hello world");
}
it throw null reference exception,i wonder how can i write to the

richtextbox MULTITHREADINGL Y,any code snippet is appreciated.

thank you!