具有活动UI并在后台运行1线程的Winform

Question

我有一个Winforms应用程序，它通过它的API调用CorelDraw，然后在保存映像之前做一些工作。我尝试使用线程、BackgroundWorker和继承了BackgroundWorker但也允许使用Thread.Abort的类来设置它。每做一次工作，我都会遇到两个问题中的一个。要么线程不在后台运行，在这种情况下，由于窗体被冻结，我无法在窗体上按下任何按钮，要么线程在后台运行，但在我第一次调用CorelDraw时立即停止处理。

有没有其他的解决办法？我们处理这个问题的老方法是让一个观察者WinForm生成另一个Process()，它可以在CorelDraw中完成所有事情。使用Process()调用的进程将重要信息保存到.txt文件中，供父进程检查，如果子进程在同一图像上工作时间过长，父进程将在其父进程上调用Kill()。到目前为止，这是一个笨重和容易出错的方式来做事情，这就是为什么我正在寻找一个更好的解决方案。

Answer 1

设计师代码：

namespace Tasks
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(41, 43);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(131, 43);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(75, 23);
            this.button2.TabIndex = 1;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(240, 116);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
    }
}

这是表单代码：

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Tasks
{
    public partial class Form1 : Form
    {
        CancellationTokenSource cts;

        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            MessageBox.Show(this,"This button still works :)");
        }

        private async void button1_Click(object sender, EventArgs e)
        {
            cts = new CancellationTokenSource();

            await CreateTask();
        }

        private async Task CreateTask()
        {
            //Create a progress object that can be used within the task
            Progress<string> mProgress; //you can set this to Int for ProgressBar
            //Set the Action to a function that will catch the progress sent within the task
            Action<string> progressTarget = ReportProgress;
            //Your new Progress with the included action function
            mProgress = new Progress<string>(progressTarget); 

            //start your task
            string result = await MyProcess(mProgress);
        }

        private Task<string> MyProcess(IProgress<string> myProgress)
        {
            return Task.Run(() =>
            {
                //To report Progress back to your UI thread
                myProgress.Report("Starting program now...");
                //Start your Corel Draw program here.
                Process.Start("C:\\WINDOWS\\system32\\notepad.exe").WaitForExit();
                //You can return the Image after your done editing it
                return "Program has been closed";

            }, cts.Token);
        }

        private void ReportProgress(string message)
        {
            //typically to update a progress bar or whatever
            MessageBox.Show(this, message);
        }
    }
}

如果您创建异步任务，您可以在后台运行Corel应用程序，然后当它关闭时，它将完成任务。我在其中添加了额外的内容，比如“进度”和“cts”，用于在父窗口关闭时取消该任务。