从 cplex 回调函数 c# 访问表单上的状态栏

Question

我正在使用 C# .Net 应用程序，该应用程序使用 Cplex DLL 进行优化操作，并且在该操作期间，我想将状态进度写入启动操作的状态栏。

这是具体表格的大体布局；

namespace ActResMain
{
    public class FormOptimize : System.Windows.Forms.Form
    {
        private callCplex()
        {
            //...
            cplex.Use(new Cplex_ContinuousCallback());
            cplex.Solve()
        }
        public void Update_OptimizeStatusbarPanel(String strText)
        {
                statusBarPanel_1.Text = strText;
                statusBar1.Refresh();
        }
        internal class Cplex_ContinuousCallback : Cplex.ContinuousCallback
        {
            FormOptimize formOpt = new FormOptimize();
            public override void Main()
            {
                //From here I want to edit the statusbar at FormOptimize. I can write progress to console without any problems, but cannot reach function "Update_OptimizeStatusbarPanel".
                //If I include "FormOptimize formOpt = new FormOptimize" here, i get Visual studio exception on illegal window reference.
            }
        }

    }
}

我也尝试过像这样调用 Update_OptimizeStatusbarPanel 函数：

internal class Cplex_ContinuousCallback : Cplex.ContinuousCallback
            {
                FormOptimize formOpt = new FormOptimize();
                public override void Main()
                {
                    FormCollection fc = Application.OpenForms;
                    var mpc = fc[1];
                    Type type = mpc.GetType(); 
                    MethodInfo dynMethod = type.GetMethod("Update_OptimizeStatusbarPanel");
                    dynMethod.Invoke(mpc, new object[] { String.Format("Running Optimization: {0} iterations ", Niterations)});
                }
            }

但是我从 Visual Studio 得到一个异常，指出一个线程创建的对象不能从另一个线程修改。

也许这是我错过的一些愚蠢的事情，但非常感谢您的帮助

编辑：我根据 Mohammad Dehghans 的建议编辑了代码，

public class FormOptimize : System.Windows.Forms.Form
{
    private callCplex()
    {
        cplex.Use(new Cplex_ContinuousCallback(this));
        cplex.Solve()
    }

    internal class Cplex_ContinuousCallback : Cplex.ContinuousCallback
    {
        FormOptimize _formOptimize;
        public Cplex_ContinuousCallback(FormOptimize formOptimize)
        {
            this._formOptimize = formOptimize;
        }

        public override void Main()
        {
            if (Niterations % 10 == 0)
            {
                _formOptimize.Update_OptimizeStatusbarPanel(0, String.Format("Running Optimization: {0} iterations ", Niterations), 0);
            }
        }
    }

    public void Update_OptimizeStatusbarPanel(short panelIndex, String strText, short severity)
    {
        if (statusBar1.InvokeRequired)
            statusBar1.Invoke(new Action<short, string, short>(Update_OptimizeStatusbarPanel), panelIndex, strText, severity);
        else
        {
            if (panelIndex == 0)
            {
                //...
                statusBarPanel_0.Text = strText;
            }
            else if (panelIndex == 1)
            {
                //...
                statusBarPanel_1.Text = strText;

            }
            statusBar1.Refresh();
        }
    }
}

但是这样做我显然破坏了一些东西，因为应用程序只是在第一次调用 statusBar1.Invoke() 之后 ..stops 。如果我暂停调试器，它会说 cplex.Solve() 正在执行，但没有任何反应。

Answer 1

首先，您需要将表单实例传递给实现的回调类，因此当调用Main 方法时，您可以访问屏幕上显示的确切实例。

其次，您需要使用Invoke 方法从另一个线程更新 UI 控件（到目前为止，我还没有使用过 CPLEX，但我猜回调是从另一个线程调用的。这很常见）。 Read this for more information.

完整的代码可以是：

public class FormOptimize : System.Windows.Forms.Form
{
    private callCplex()
    {
        //Misc code
        cplex.Use(new Cplex_ContinuousCallback(this)); // <-- passing `this`
        cplex.Solve()
        //Misc code
    }

    public void Update_OptimizeStatusbarPanel(String strText)
    {
        if (statusBarPanel_1.InvokeRequired)
            statusBarPanel_1.Invoke(Action<string>(Update_OptimizeStatusbarPanel), strText);
        else
        {
            statusBarPanel_1.Text = strText;
            statusBar1.Refresh();
        }
    }

    internal class Cplex_ContinuousCallback : Cplex.ContinuousCallback
    {
        FormOptimize _formOptimize;
        public Cplex_ContinuousCallback(FormOptimize formOptimize)
        {
            this._formOptimize = formOptimize;
        }

        public override void Main()
        {
            //...
            _formOptimize.Update_OptimizeStatusbarPanel(String.Format("Running Optimization: {0} iterations ", Niterations));
        }
    }
}