Question

我需要调用C dll作为后台进程。 dll的执行是耗时的，因此我想在主GUI上显示进度条。为了使用ReportProgress，我需要能够通过引用传递两个参数，并在参数值发生变化时更新进度条。但是，RunWorkerAsync似乎只接受值（而不是引用）。

我该怎么办？

感谢。

以下是简化代码：

public void button1_Click(object sender, EventArgs e)
    {
       //Variable declarations and initializations

       List<object> arguments = new List<object>();
                arguments.Add(curgen);
                arguments.Add(dataindex);

        backgroundWorker1.RunWorkerAsync(arguments);
        backgroundWorker1.ReportProgress(curgen * 100 / ngen, "GEN");
        backgroundWorker1.ReportProgress(dataindex * 100 / (DIMENSION * FITNESSCASES), "DATA");

    }

 private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        List<object> genericlist = e.Argument as List<object>;
        // Getting variables from object
         calldll.gpinnovization(ref curgen, ref dataindex);
    }

我想通过引用传递'curgen'和'dataindex'。

Answer 1

您可以使用lambda作为DoWork事件处理程序来关闭变量（注意闭包关闭变量，而不是值，因此这不会只复制值）。从那里你可以在lambda中做正确的工作，或者通过引用将变量传递给其他方法。

int someValue = 5;

BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += (s, args) =>
{
    ProcessValue(ref someValue);
};
worker.RunWorkerAsync();

Answer 2

为了别人的利益，这就是我最终如何做到的。感谢Servy建议使用lambda表达式：

        BackgroundWorker backgroundWorker1 = new BackgroundWorker();
        backgroundWorker1.WorkerReportsProgress = true;
        backgroundWorker1.DoWork += (s, args) =>
            {
                Mydll.MyCfunction(ref curgen, ref dataindex);
            };
        backgroundWorker1.RunWorkerAsync();
        backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;


        while (backgroundWorker1.IsBusy)
        {
            backgroundWorker1.ReportProgress(curgen * 100 / ngen, "GEN");
            backgroundWorker1.ReportProgress(dataindex * 100 / (DIMENSION * FITNESSCASES), "DATA");
            Application.DoEvents();
        }

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e1)
    {
        switch (e1.UserState.ToString())
        {
            case "GEN":
                progressBar1.Value = e1.ProgressPercentage;
                break;
            case "DATA":
                progressBar2.Value = e1.ProgressPercentage;
                break;
        }

    }

通过引用BackgroundWorker传递参数

2 个答案: