后台线程调用界面线程显示

最新推荐文章于 2022-06-22 14:54:56 发布

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使用委托调用的三个步骤:
1.定义一个与指定方法的格式相匹配的委托
2.创建自定义委托实例，将方法名作为构造函数的参数
3.通过调用调用委托对象的Invoke（）间接调用该方法

可以通过使用内置委托action<> Fun<>委托
Action指向无返回值得方法
Fun指向有返回值的方法

后台线程调用主线程控件的方法
1.

//声明委托
private delegate bool Process
//声明事件
public event Process process;
private bool DelegateThing()
{
}
//注册委托
 process+=new Process(DelegateThing);
 调用
 bool result=(bool)this.invoke(process);

2.匿名方法使用Action或者Func

//	委托的简单用法
//Action<T>是无返回值的委托,Fun<T>有返回值的委托
 Func<string, bool> processDelegate = new Func<string, bool>((x) => 
        {
            return false;
        });
   bool result=(bool)this.invoke(processDelegate,"null");

3.0个参数无返回值的调用可以使用更简单的方法

this.Invoke(new MethodInvoker(delegate {   }));
this.Invoke(new MethodInvoker(（）=>{  }));

4:在前台线程建立函数以便后台线程调用:

 private delegate bool SetPos(int ipos, string vinfo);
  public bool SetProgressBar(int ipos,string messags)
        {
            if (this.InvokeRequired)
            {
                SetPos setpos = new SetPos(SetProgressBar);
                this.BeginInvoke(setpos, new object[] { ipos, messags });
            }
            else
            {
               		DoSometing();
            }
            return false;
        }

最笨的办法,但是可以多次调用,将显示函数独立出来:

private delegate void ShowFormGanzaoji(GanzaojiData ganzaojiData);
private ShowFormGanzaoji showFormGanzaoji;

    private void ShowGanZaoji(GanzaojiData ganzaojiData)
    {
        if (this.InvokeRequired)
        {
            showFormGanzaoji = ShowGanZaoji;
            this.Invoke(showFormGanzaoji, ganzaojiData);
        }
        else
        {
            object shijiwendu = ganzaojiData.ShijiWendu;
            shijiwendu = (shijiwendu == null) ? "" : shijiwendu;
            txtGZJshiji.Text = shijiwendu.ToString();
            if (ganzaojiData.ChaowenJingbao)
                PaintEllipse(panelGZJchaowen, Color.Red);
            if (ganzaojiData.GanWentouJingbao)
                PaintEllipse(panelGZJganwen, Color.Red);
            if (ganzaojiData.GuozhaiJingbao)
                PaintEllipse(panelGZJguozhai, Color.Red);
            if (ganzaojiData.DianchiJiingBao)
                PaintEllipse(panelGZJdianchi, Color.Red);
            if (ganzaojiData.ChaowenJingbao != false || ganzaojiData.GanWentouJingbao != false || ganzaojiData.GuozhaiJingbao != false || ganzaojiData.DianchiJiingBao != false)
            {
                PaintEllipse(panelGZJYunXing, Color.Red);
            }
        }
    }