我正在尝试建立一个程序，该程序可用于从TcpClient读取传入的数据包。这个想法是在while循环中连续读取数据并将其显示在RTF文本框元素中。举例来说，我一直试图像这样设置程序（tcp客户端的阅读部分被省略以减少代码量）：
program.cs-主要入口点：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Testing
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
}
类，其中设置了while循环：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
namespace Testing
{
class Whiler
{
public static void Stremer()
{
Thread Streamer = new Thread(OutPutFromWhile);
Streamer.Start();
OutPutFromWhile();
}
public static void OutPutFromWhile()
{
int i = 0;
Form1 mybox = new Form1();
// I want to display all i values from this while loop in the textbox
while (true)
{
i++;
mybox.richTextBox1.AppendText(i.ToString() + Environment.NewLine);
}
}
}
}
Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Testing
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Whiler.Stremer();
}
}
}
Forms1.Designer.cs
namespace Testing
{
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.richTextBox1 = new System.Windows.Forms.RichTextBox();
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// richTextBox1
//
this.richTextBox1.Location = new System.Drawing.Point(56, 103);
this.richTextBox1.Name = "richTextBox1";
this.richTextBox1.Size = new System.Drawing.Size(659, 280);
this.richTextBox1.TabIndex = 0;
this.richTextBox1.Text = "";
//
// button1
//
this.button1.Location = new System.Drawing.Point(56, 29);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(658, 52);
this.button1.TabIndex = 1;
this.button1.Text = "button1";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(800, 450);
this.Controls.Add(this.button1);
this.Controls.Add(this.richTextBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
public System.Windows.Forms.RichTextBox richTextBox1;
private System.Windows.Forms.Button button1;
}
}
答案 0 :(得分：2)
UI线程是唯一可以执行UI操作的线程！
您将遇到的问题之一是非UI线程将尝试更新用户界面。只有UI线程可以执行此操作。
您可以考虑使用BackgroundWorker进行阅读。
您可以决定创建一个从BackgroundWorker派生的类来完成您的工作。但是，由于您的BackgroundWorker没有很多功能，因此使用标准BackGroundWorker及其DoWork事件也很容易。
使用Windows窗体设计器添加BackgroundWorker。在属性窗口中更改属性。
WorkerReportsProgress = true;
WorkerSupportsCancel = true;
对事件做出反应
DoWork = DoBackGroundWork
ProgressChanged = ReportProgress
RunWorkerCompleted = ReportBackgroundWorkCompleted
或者使用构造函数：
private readonly BackGroundWorker backgroundWorker;
public Form1()
{
InitializeComponent();
this.backgroundWorker = new BackgroundWorker
{
WorkerReportsProgress = true,
WorkerSupportsCancellation = true,
};
// Subscribe to events:
backgroundWorker.DoWork += this.DoBackGroundWork;
backgroundWorker.ProgressChanged += this.OnReportProgress;
backgroundWorker.RunWorkerCompleted += this.ReportBackgroundWorkCompleted;
// make sure that the BackgroundWorker is properly disposed if this form is disposed:
if (this.components == null) this.components = new System.ComponentModel.Container();
this.components.Add(this.backgroundWorker);
}
DoBackgroundWork 是执行后台工作的事件函数。该功能由后台工作者执行。它不是UI线程。请勿在此表单上做任何事情。执行后台工作者需要做的事情当必须显示某些数据时，请致电ReportProgress。定期检查CancellationPending，看看它是否应该停止工作
private void DoBackGroundWork(object sender, DoWorkEventArgs e)
{
var backgroundWorker = (BackgroundWorker)sender;
While(!backgroundWorker.CancellationPending)
{
// continue producing output
var producedOutput = ...
// report that new output is available:
backgroundWorker.ReportProgress(0, producedOutput);
}
}
ReportProgress中的第一个参数是一个数字，指示此后台线程的进度。 UI可以使用它来填充进度栏。由于您不知道将要生成多长时间，因此无法填写正确的数字。
当后台工作人员报告进度时，会调用OnReportProgress 此功能由UI线程执行。随意做与UI相关的任何事情
private void OnReportProgress(object sender, ProgressChangedEventArgs e)
{
// you know the type that is reported as progress,
// it is the type of the produced output
string producedText = (string)e.UserState;
this.AddToRichTextBox(producedText);
}
ReportBackgroundWorkCompleted 仅在后台工作人员完成后需要执行某些操作时才需要。它由UI线程执行
private void ReportBackgroundWorkCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// finished background working. Do some cleanup
this.ShowBackgroundWorkerActive(false); // for example: hide ajax loader gif
}
使用后台工作者：
void ShowBackGroundWorkerActive(bool active)
{
// give user indication about active backgroundworker, for instance show ajax loader gif
this.GifBackgroundWorkerActive.Visible = active;
}
bool IsBackGroundWorkerActive => this.GifBackgroundWorkerActive.Visible;
void StartBackgroundWorking()
{
if (this.IsBackgroundWorkerActive) return; // already active
// do some preparations:
this.ShowBackgroundWorkerActive(true);
// start the backgroundworker
this.backgroundWorker.RunWorkerAsync();
}
void CancelBackgroundWorking()
{
this.backgroundWorker.CancelAsync();
}
如果要关闭表单，请停止后台工作
您唯一要做的就是确保没有使用活动的后台工作程序关闭窗口。为此，请使用事件OnFormClosing。
bool formClosingRequested = false;
void OnFormClosing(object sender, FormClosingEventArgs e)
{
if (this.BackGroundWorkerActive)
{
// can't close right now: need to stop the backgroundWorker first.
// remember that we want to close the form:
this.formClosingRequested = true;
this.CancelBackgroundWorking();
e.Cancel = true;
}
// else, no reason to cancel closing
}
后台工作人员完成后，在请求从头关闭后，我们将不得不关闭表单。
void ReportBackgroundWorkCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// finished background working. Do some cleanup
this.ShowBackgroundWorkerActive(false);
if (this.formClosingRequested)
{
// Close the form. This will lead to a FormClosingEvent
// but this time the background worker won't be active
this.Close();
}
}
答案 1 :(得分：1)
UI控件确实仅需要从UI线程访问。这可以使用winforms BeginInvoke方法完成，该方法会将指定的代码推送到UI线程的队列中。使用您的示例代码...
while (true)
{
i++;
mybox.BeginInvoke ((MethodInvoker) delegate
{
mybox.richTextBox1.AppendText(i.ToString() + Environment.NewLine);
});
}
这将解决访问问题。
但是请注意，您仍然可以通过使用BeginInvokes充斥UI线程来挂起UI线程，此紧密循环可能会这样做。我以为这只是一个例子，TCP数据的传输速度会慢得多，频率也会降低。如果没有，那么您可能需要重新考虑并可能将其批处理，或者仅在特定时间间隔后更新。