关于ProgressBar 与多线程 的问题？

Question

想在用户进行某些比较耗时的操作时，弹出个带进度条的等待窗体，不能让用户再进行其他的操作，我知道是用多线程，但是对其不熟悉，最好能有代码！！！
谢谢！！！

Answer 1

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Threading;
 
  private bool flag=false;
  private System.Threading.Thread timerThread;
  private int a=0;
 
private void StopThread()
{
 if (timerThread != null)
 {
  timerThread.Interrupt();
  timerThread = null;
 }
}
public void ThreadProc()
{
 
 for (int i = 0; i < 10000; i++)
 {
  for (int j = 0; j < 10000; j++) ;
  a = a + i;
 }
 flag=true;
 
}
private void progress_Load(object sender, System.EventArgs e)
{
 this.progressBar1.Minimum = 0;
 this.progressBar1.Maximum = 10000;
}
private void button1_Click(object sender, System.EventArgs e)
{
 StopThread();
 timerThread = new Thread(new ThreadStart(ThreadProc));
 timerThread.IsBackground = true;
 timerThread.Start();
 while (flag == false)
 {
  while (this.progressBar1.Value < this.progressBar1.Maximum)
   this.progressBar1.Value += 1;
  if (progressBar1.Value == progressBar1.Maximum)
   this.progressBar1.Value = 0;
 }
 Form1 frm1=new Form1(a.ToString());
 frm1.Show();
}
}

Answer 2

这种也不一定需要多线程，多线程操作很麻烦，而且容易出错最好是在你耗时的操作之间更新进度条，这样很简单比如你要读1W条数据，可以每循环100次的时候改变进度条一次，然后调用进度条的Refresh方法

Answer 3

顶楼上的代码和见解。我增加一些。希望能给些好的提示。
this.progressBar1.Step = 20;
this.progressBar1.PerformStep();来设定progressBar每次增加的步长。在每执行PerformStep方法一次。可以这个思路。

Answer 4

http://blog.csdn.net/jinjazz/archive/2008/05/24/2477088.aspx

Answer 5

可以通过backgroundWorker类来做，下面是Demo。
下面的程序示例创建了一个计算 Fibonacci 数的窗体。该计算运行于用户界面线程之外的另一个线程上，因此用户界面可在计算进行的同时继续运行，而不会出现延迟。using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;namespace BackgroundWorkerExample
{
    public class FibonacciForm : System.Windows.Forms.Form
    {
        private int numberToCompute = 0;
        private int highestPercentageReached = 0;        private System.Windows.Forms.NumericUpDown numericUpDown1;
        private System.Windows.Forms.Button startAsyncButton;
        private System.Windows.Forms.Button cancelAsyncButton;
        private System.Windows.Forms.ProgressBar progressBar1;
        private System.Windows.Forms.Label resultLabel;
        private System.ComponentModel.BackgroundWorker backgroundWorker1;        public FibonacciForm()
        {
            InitializeComponent();            InitializeBackgoundWorker();
        }        // Set up the BackgroundWorker object by 
        // attaching event handlers. 
        private void InitializeBackgoundWorker()
        {
            backgroundWorker1.DoWork += 
                new DoWorkEventHandler(backgroundWorker1_DoWork);
            backgroundWorker1.RunWorkerCompleted += 
                new RunWorkerCompletedEventHandler(
            backgroundWorker1_RunWorkerCompleted);
            backgroundWorker1.ProgressChanged += 
                new ProgressChangedEventHandler(
            backgroundWorker1_ProgressChanged);
        }

        private void startAsyncButton_Click(System.Object sender, 
            System.EventArgs e)
        {
            // Reset the text in the result label.
            resultLabel.Text = String.Empty;            // Disable the UpDown control until 
            // the asynchronous operation is done.
            this.numericUpDown1.Enabled = false;            // Disable the Start button until 
            // the asynchronous operation is done.
            this.startAsyncButton.Enabled = false;            // Enable the Cancel button while 
            // the asynchronous operation runs.
            this.cancelAsyncButton.Enabled = true;            // Get the value from the UpDown control.
            numberToCompute = (int)numericUpDown1.Value;            // Reset the variable for percentage tracking.
            highestPercentageReached = 0;            // Start the asynchronous operation.
            backgroundWorker1.RunWorkerAsync(numberToCompute);
        }        private void cancelAsyncButton_Click(System.Object sender, 
            System.EventArgs e)
        {   
            // Cancel the asynchronous operation.
            this.backgroundWorker1.CancelAsync();            // Disable the Cancel button.
            cancelAsyncButton.Enabled = false;
        }        // This event handler is where the actual,
        // potentially time-consuming work is done.
        private void backgroundWorker1_DoWork(object sender, 
            DoWorkEventArgs e)
        {   
            // Get the BackgroundWorker that raised this event.
            BackgroundWorker worker = sender as BackgroundWorker;            // Assign the result of the computation
            // to the Result property of the DoWorkEventArgs
            // object. This is will be available to the 
            // RunWorkerCompleted eventhandler.
            e.Result = ComputeFibonacci((int)e.Argument, worker, e);
        }        // This event handler deals with the results of the
        // background operation.
        private void backgroundWorker1_RunWorkerCompleted(
            object sender, RunWorkerCompletedEventArgs e)
        {
            // First, handle the case where an exception was thrown.
            if (e.Error != null)
            {
                MessageBox.Show(e.Error.Message);
            }
            else if (e.Cancelled)
            {
                // Next, handle the case where the user canceled 
                // the operation.
                // Note that due to a race condition in 
                // the DoWork event handler, the Cancelled
                // flag may not have been set, even though
                // CancelAsync was called.
                resultLabel.Text = "Canceled";
            }
            else
            {
                // Finally, handle the case where the operation 
                // succeeded.
                resultLabel.Text = e.Result.ToString();
            }            // Enable the UpDown control.
            this.numericUpDown1.Enabled = true;            // Enable the Start button.
            startAsyncButton.Enabled = true;            // Disable the Cancel button.
            cancelAsyncButton.Enabled = false;
        }        // This event handler updates the progress bar.
        private void backgroundWorker1_ProgressChanged(object sender,
            ProgressChangedEventArgs e)
        {
            this.progressBar1.Value = e.ProgressPercentage;
        }        // This is the method that does the actual work. For this
        // example, it computes a Fibonacci number and
        // reports progress as it does its work.
        long ComputeFibonacci(int n, BackgroundWorker worker, DoWorkEventArgs e)
        {
            // The parameter n must be >= 0 and <= 91.
            // Fib(n), with n > 91, overflows a long.
            if ((n < 0) || (n > 91))
            {
                throw new ArgumentException(
                    "value must be >= 0 and <= 91", "n");
            }            long result = 0;            // Abort the operation if the user has canceled.
            // Note that a call to CancelAsync may have set 
            // CancellationPending to true just after the
            // last invocation of this method exits, so this 
            // code will not have the opportunity to set the 
            // DoWorkEventArgs.Cancel flag to true. This means
            // that RunWorkerCompletedEventArgs.Cancelled will
            // not be set to true in your RunWorkerCompleted
            // event handler. This is a race condition.            if (worker.CancellationPending)
            {   
                e.Cancel = true;
            }
            else
            {   
                if (n < 2)
                {   
                    result = 1;
                }
                else
                {   
                    result = ComputeFibonacci(n - 1, worker, e) + 
                             ComputeFibonacci(n - 2, worker, e);
                }                // Report progress as a percentage of the total task.
                int percentComplete = 
                    (int)((float)n / (float)numberToCompute * 100);
                if (percentComplete > highestPercentageReached)
                {
                    highestPercentageReached = percentComplete;
                    worker.ReportProgress(percentComplete);
                }
            }            return result;
        }

Answer 6

#region Windows Form Designer generated code

        private void InitializeComponent()
        {
            this.numericUpDown1 = new System.Windows.Forms.NumericUpDown();
            this.startAsyncButton = new System.Windows.Forms.Button();
            this.cancelAsyncButton = new System.Windows.Forms.Button();
            this.resultLabel = new System.Windows.Forms.Label();
            this.progressBar1 = new System.Windows.Forms.ProgressBar();
            this.backgroundWorker1 = new System.ComponentModel.BackgroundWorker();
            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).BeginInit();
            this.SuspendLayout();
            // 
            // numericUpDown1
            // 
            this.numericUpDown1.Location = new System.Drawing.Point(16, 16);
            this.numericUpDown1.Maximum = new System.Decimal(new int[] {
            91,
            0,
            0,
            0});
            this.numericUpDown1.Minimum = new System.Decimal(new int[] {
            1,
            0,
            0,
            0});
            this.numericUpDown1.Name = "numericUpDown1";
            this.numericUpDown1.Size = new System.Drawing.Size(80, 20);
            this.numericUpDown1.TabIndex = 0;
            this.numericUpDown1.Value = new System.Decimal(new int[] {
            1,
            0,
            0,
            0});
            // 
            // startAsyncButton
            // 
            this.startAsyncButton.Location = new System.Drawing.Point(16, 72);
            this.startAsyncButton.Name = "startAsyncButton";
            this.startAsyncButton.Size = new System.Drawing.Size(120, 23);
            this.startAsyncButton.TabIndex = 1;
            this.startAsyncButton.Text = "Start Async";
            this.startAsyncButton.Click += new System.EventHandler(this.startAsyncButton_Click);
            // 
            // cancelAsyncButton
            // 
            this.cancelAsyncButton.Enabled = false;
            this.cancelAsyncButton.Location = new System.Drawing.Point(153, 72);
            this.cancelAsyncButton.Name = "cancelAsyncButton";
            this.cancelAsyncButton.Size = new System.Drawing.Size(119, 23);
            this.cancelAsyncButton.TabIndex = 2;
            this.cancelAsyncButton.Text = "Cancel Async";
            this.cancelAsyncButton.Click += new System.EventHandler(this.cancelAsyncButton_Click);
            // 
            // resultLabel
            // 
            this.resultLabel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
            this.resultLabel.Location = new System.Drawing.Point(112, 16);
            this.resultLabel.Name = "resultLabel";
            this.resultLabel.Size = new System.Drawing.Size(160, 23);
            this.resultLabel.TabIndex = 3;
            this.resultLabel.Text = "(no result)";
            this.resultLabel.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
            // 
            // progressBar1
            // 
            this.progressBar1.Location = new System.Drawing.Point(18, 48);
            this.progressBar1.Name = "progressBar1";
            this.progressBar1.Size = new System.Drawing.Size(256, 8);
            this.progressBar1.Step = 2;
            this.progressBar1.TabIndex = 4;
            // 
            // backgroundWorker1
            // 
            this.backgroundWorker1.WorkerReportsProgress = true;
            this.backgroundWorker1.WorkerSupportsCancellation = true;
            // 
            // FibonacciForm
            // 
            this.ClientSize = new System.Drawing.Size(292, 118);
            this.Controls.Add(this.progressBar1);
            this.Controls.Add(this.resultLabel);
            this.Controls.Add(this.cancelAsyncButton);
            this.Controls.Add(this.startAsyncButton);
            this.Controls.Add(this.numericUpDown1);
            this.Name = "FibonacciForm";
            this.Text = "Fibonacci Calculator";
            ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).EndInit();
            this.ResumeLayout(false);        }
#endregion        [STAThread]
        static void Main()
        {
            Application.Run(new FibonacciForm());
        }
    }
}

Answer 7

private void StopThread()
{
 if (timerThread != null)
 {
  timerThread.Interrupt();
  timerThread = null;
 }
}
public void ThreadProc()
{
 
 for (int i = 0; i < 10000; i++)
 {
  for (int j = 0; j < 10000; j++) ;
  a = a + i;
 }
 flag=true;
 
}
private void progress_Load(object sender, System.EventArgs e)
{
 this.progressBar1.Minimum = 0;
 this.progressBar1.Maximum = 10000;
}
private void button1_Click(object sender, System.EventArgs e)
{
 StopThread();
 timerThread = new Thread(new ThreadStart(ThreadProc));
 timerThread.IsBackground = true;
 timerThread.Start();
 while (flag == false)
 {
  while (this.progressBar1.Value < this.progressBar1.Maximum)
   this.progressBar1.Value += 1;
  if (progressBar1.Value == progressBar1.Maximum)
   this.progressBar1.Value = 0;
 }
 Form1 frm1=new Form1(a.ToString());
 frm1.Show();
}
}