如何使用 WinForms 进度条? [英] How to use WinForms progress bar?

问题描述

我想显示在外部库中执行的计算进度.

I want to show progress of calculations, which are performing in external library.

例如，如果我有一些计算方法，并且我想在我的 Form 类中将它用于 100000 个值，我可以这样写:

For example if I have some calculate method, and I want to use it for 100000 values in my Form class I can write:

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

    private void Caluculate(int i)
    {
        double pow = Math.Pow(i, i);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        progressBar1.Maximum = 100000;
        progressBar1.Step = 1;

        for(int j = 0; j < 100000; j++)
        {
            Caluculate(j);
            progressBar1.PerformStep();
        }
    }
}

我应该在每次计算后执行步骤.但是如果我在外部方法中执行所有 100000 次计算呢?如果我不想让这个方法依赖于进度条，我应该什么时候执行步骤"?例如，我可以写

I should perform step after each calculation. But what if I perform all 100000 calculations in external method. When should I "perform step" if I don't want to make this method dependant on progress bar? I can, for example, write

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

    private void CaluculateAll(System.Windows.Forms.ProgressBar progressBar)
    {
        progressBar.Maximum = 100000;
        progressBar.Step = 1;

        for(int j = 0; j < 100000; j++)
        {
            double pow = Math.Pow(j, j); //Calculation
            progressBar.PerformStep();
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        CaluculateAll(progressBar1);
    }
}

但我不想那样做.

推荐答案

我建议你看看 BackgroundWorker.如果您的 WinForm 中有一个如此大的循环，它将被阻塞，您的应用程序看起来就像挂了一样.

I would suggest you have a look at BackgroundWorker. If you have a loop that large in your WinForm it will block and your app will look like it has hanged.

查看 BackgroundWorker.ReportProgress() 以了解如何将进度报告回 UI 线程.

Look at BackgroundWorker.ReportProgress() to see how to report progress back to the UI thread.

例如:

private void Calculate(int i)
{
    double pow = Math.Pow(i, i);
}

private void button1_Click(object sender, EventArgs e)
{
    progressBar1.Maximum = 100;
    progressBar1.Step = 1;
    progressBar1.Value = 0;
    backgroundWorker.RunWorkerAsync();
}

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
    var backgroundWorker = sender as BackgroundWorker;
    for (int j = 0; j < 100000; j++)
    {
        Calculate(j);
        backgroundWorker.ReportProgress((j * 100) / 100000);
    }
}

private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
}

private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    // TODO: do something with final calculation.
}

这篇关于如何使用 WinForms 进度条?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！