Question

我正在构建Windows窗体应用程序，并在其中创建了UserControl（称为MyControl）。

此UserControl可以使用BackgroundWorker生成并返回一个值。

我的问题是，我的form1如何在计算完成后实时显示UserControl产生的值？

public partial class MyControl : UserControl
{
    BackgroundWorker bgWorker;
    private string _num;

        public string Num
        {
            get
            {
                return _num;
            }
            set
            {
                _num = value;
            }
        }

        public MyControl()
        {
            InitializeComponent();

            bgWorker = new BackgroundWorker();
            bgWorker.DoWork += new DoWorkEventHandler(bgWorker_DoWork);
            bgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgWorker_RunWorkerCompleted);
        }

        void bgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.BeginInvoke((MethodInvoker)delegate
            {
                //Done
                MessageBox.Show(e.Result.ToString());
                //↑↑↑↑↑ HERE
                //I want to return to form1
                // like to rewrite: form1.textbox1.text = e.Result.ToString();
            });

            btnStartAsyncOperation.Enabled = true;
            btnCancel.Enabled = false;
        }

        void bgWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            string Num = A_huge_calculation();
            e.Result = Num;
        }

        private void RunCalculate(string Num)
        {
            if (bgWorker.IsBusy != true)
            {
                bgWorker.RunWorkerAsync(Num);
            }
        }

        private void btnStartAsyncOperation_Click(object sender, EventArgs e)
        {
            RunCalculate(_num);

        }
    }
}

为什么使用BackgroundWorker？因为它将做不可预测的事情（例如为任何文件生成MD5和SHA1校验和），而且我不想让最终用户睡着的主要形式。

除了form2之外，还将像Form1一样添加此UserControl，并分配唯一控件以显示该值。

form2.cs

public partial class Form2 : Form
{
    MyControl mycontrol;
    private void Form2_Load(object sender, EventArgs e)
    {
        mycontrol.SentTO = 'richtextBox1';
        //It can be assign any container name to receive the value when completed.
        //when trigger the execute button inside the MyControl
    }
    private void button1_Click(object sender, EventArgs e)
    {
        mycontrol = new MyControl();
        mycontrol.Num = "xxxxxx";

        //run mycontrol
        //mycontrol.run();

        richtextBox2.Text = mycontrol.value; //Here, when the MyControl calculation is completed.

    }
}

我还一直在考虑设置一个计时器，以每1000毫秒侦听此用户控件获取值。

form1.cs

    private void timer1_Tick(object sender, EventArgs e)
    {
        if( ! string.IsNullOrEmpty(mycontrol.value))
        {
            richtextBox2.Text = mycontrol.value; //here is when the MyControl calculation is completed.
            timer1.Stop();
        }
    }

过去的理想是通过MyControl来访问timer的公共价值， MyControl完成后，它将返回非null值，并且timer停止MyControl检测。但是，这将衍生出为什么MyControl可以知道timer中的form1名称是什么？或将form1设置为两个或更多MyControls，则需要更多timers来检测每个MyControl。

如何从UserControl实时获取结果？

0 个答案: