在WinForm中使用委托来在其他线程中改变控件的显示

假设winform中有两个控件:

1.ListView用来显示进度的文本提示,ID:listView_progressInfo

2.ProgressBar用来显示进度,ID:progressBar1

在此winform的后台.cs文件中声明两个公用委托类型:ControlChanger, ProgressChanger

    public delegate void ControlChanger(string progressText);
    public delegate void ProgressChanger(int current, int total);

并且编写操作上面两个控件的函数,它们都在此winform的线程内运行,故修改控件时不会报“非创建控件的线程不可修改控件”的错误:

        public void AddProgressIntoListView(string text)
        {
            if (listView_progressInfo.InvokeRequired)
            {
                ControlChanger outdelegate = new ControlChanger(AddProgressIntoListView);
                this.BeginInvoke(outdelegate, new object[] { text });
                return;
            }
            listView_progressInfo.Items.Add(new ListViewItem(text));
        }

        public void SetProgressBarValue(int current, int total)
        {
            if (progressBar1.InvokeRequired)
            {
                ProgressChanger outdelegate = new ProgressChanger(SetProgressBarValue);
                this.BeginInvoke(outdelegate, new object[] { current, total });
                return;
            }
            progressBar1.Value = (int)(100 * current / total);
        }

检查控件InvokeRequired属性是为了保证安全地访问控件,参考微软知识库:

https://msdn.microsoft.com/en-us/library/ms171728(v=vs.110).aspx

新建一个类用来操作winform中的控件: 

    public class ControlChange
    {
        public ControlChanger cc = null;
        public ProgressChanger pc = null;

        public void ChangeControlAndProgress()
        {
            int taskCount = 100;
            for (int i = 0; i <= taskCount; i++)
            {
                if (null != cc)
                {
                    cc(string.Format("任务进行中,进度{0}%", i));
                }

                if (null != cc)
                {
                    pc(i,taskCount);
                }
                System.Threading.Thread.Sleep(500);
            }
        }
    }

然后在触发器中(可以是一个按钮)写入如下代码:

        private void button_start_Click(object sender, EventArgs e)
        {
            ControlChange controlchange = new ControlChange();
            controlchange.cc = new ControlChanger(AddProgressIntoListView);//将ControlChanger委托类型的变量cc实例化
            controlchange.pc = new ProgressChanger(SetProgressBarValue);//将ProgressChanger委托类型的变量cc实例化
            new Thread(new ThreadStart(controlchange.ChangeControlAndProgress)).Start();//新建线程来运行ControlChange中的修改控件的方法ChangeControlAndProgress
        }

触发器触发后即可看到窗体中的进度提示和进度条在走。

原文地址:https://www.cnblogs.com/vaecole/p/changeControlsInOtherThread_Winform.html