欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

C# 线程更新UI

程序员文章站 2022-06-10 14:15:37
...

最方便的用法:

private void ViewMsg(string msg)
        {

/*

control.Invoke(new SetControlTextDelegate((ct, v) => { ct.Text = v; }), new object[] { control, value });
=>
control.Invoke(new Action<Control, string>((ct, v) => { ct.Text = v; }), new object[] { control, value });

*/
            this.rtb.Invoke(new Action<RichTextBox, string>((ct, v) => { ct.AppendText(v); ct.Refresh(); }),
                    new object[] { this.rtb, msg });
            this.rtb.Invoke(new Action<string>((v) => { this.rtb.AppendText(v); this.rtb.Refresh(); }),
                    msg);
        }

Because Invoke/BeginInvoke accepts Delegate (rather than a typed delegate), you need to tell the compiler what type of delegate to create ; MethodInvoker (2.0) or Action (3.5) are common choices (note they have the same signature); like so:

control.Invoke((MethodInvoker)delegate{this.Text="Hi";});

If you need to pass in parameters, then "captured variables" are the way:

string message ="Hi";
control.Invoke((MethodInvoker)delegate{this.Text= message;});

(caveat: you need to be a bit cautious if using captures async, but sync is fine - i.e. the above is fine)

Another option is to write an extension method:

public static void Invoke(thisControl control,Action action){
    control.Invoke((Delegate)action);}

then:

this.Invoke(delegate{this.Text="hi";});// or simce we are using C# 3.0this.Invoke(()=>{this.Text="hi";});

You can of course do the same with BeginInvoke:

publicstaticvoidBeginInvoke(thisControl control,Action action){
    control.BeginInvoke((Delegate)action);}

If you can't use C# 3.0, you could do the same with a regular instance method, presumably in a Form base-class.