Question

我有以下代码读取文件，并在阅读时增加te进度条，但我在progressBar中没有看到任何活动。谁能帮助我为什么？

progressBar1.Minimum = 0;
progressBar1.Maximum = (int)fileStream.Length + 1;
progressBar1.Value = 0;

using (fileStream)
{
    fileStreamLength = (int)fileStream.Length + 1;
    fileInBytes = new byte[fileStreamLength];
    int currbyte = 0, i = 0;
    var a = 0;
    while (currbyte != -1)
    {
        currbyte = fileStream.ReadByte();
        fileInBytes[i++] = (byte)currbyte;
        progressBar1.Value=i;

    }

 }

Answer 1

它正在递增，但你看不到它。它是由在UI线程中运行循环引起的。查找BackGroundWorker或async / await模式。

Answer 2

用户Method Invoker更新用户界面... 试试这个...

在线程中完成所有工作，并在更新progressbar时使用以下行...

对于Windows窗体

this.Invoke((MethodInvoker) delegate
{
progressBar1.value=i;
});

对于WPF

Dispatcher.BeginInvoke(new Action(delegate
{
progressBar1.value=i;
}));

Answer 3

您最好的选择是Background Worker 从工具箱中拖放BackgroundWorker。然后你必须实现2个功能：一个是后台工作，另一个是向UI报告。

using System.ComponentModel;
using System.Threading;

public partial class Form1 : Form
{
public Form1()
{
    InitializeComponent();
}

private void Form1_Load(object sender, System.EventArgs e)
{
    // Start the BackgroundWorker.
    backgroundWorker1.RunWorkerAsync();
}

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
        // begin reading your file here...

        // set the progress bar value and report it to the main UI
        int i = 0; // value between 0~100
        backgroundWorker1.ReportProgress(i);
}

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    // Change the value of the ProgressBar to the BackgroundWorker progress.
    progressBar1.Value = e.ProgressPercentage;
    // Set the text.
    this.Text = e.ProgressPercentage.ToString();
}
}

进度条不递增

3 个答案: