线程在C＃中的问题（A字段初始不能引用非静态字段，ECT） [英] Threading problems in C# (A field initializer cannot reference the non-static field, ect)

问题描述

林具有在C＃中的线程一个很烦人的问题。我得到的错误一个字段初始不能引用非静态字段，方法或属性Scraper.Form1.scrapeStart（）'当使用此代码：

Im having a quite annoying problem with threading in C#. I get the error "A field initializer cannot reference the non-static field, method, or property 'Scraper.Form1.scrapeStart()'" When using this code:

public partial class Form1 : Form
{
    public Thread scrape = new Thread(() => scrapeStart()); //This is where the error happens
    public About about = new About();
    public Form1()
    {
        InitializeComponent();
    }

    public void appendOutput(String s)
    {
        output.AppendText(s);
        output.SelectionStart = output.Text.Length;
        output.ScrollToCaret();
        output.Refresh();
    }

    public void scrapeStart(){
        Button button1 = new Button();
        appendOutput("");
        button1.Enabled = true;
    }

    private void button3_Click(object sender, EventArgs e)
    {
        about.ShowDialog();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        button1.Enabled = false;
        scrape.Start();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        scrape.Abort();
        button1.Enabled = true;
    }
}

我意识到，如果我做了功能scrapeStart静态它会的工作，但是这将使appendOutput（）;和button1.Enabled =真抛出的错误。如果我把在其开始（的button1_Click），那么它不能在button2_Click被终止。

I realize that if I made the function scrapeStart static it would work, but that would make appendOutput(""); and button1.Enabled = true throw errors. And if I put the new Thread in where its started (button1_Click) then it cannot be aborted in button2_Click.

我是个有点早知道C＃所以我可能要么所做的一切都是新的线程可怕的错误，或者它可能只是一个小问题。但无论哪种方式，可能有人请帮助我吗？

Im a bit knew to C# so I may have either done everything horribly wrong, or it may just be a small problem. But either way, could someone please help me?

推荐答案

这真的无关线程。如果你写的，你会看到完全一样的问题：

This really has nothing to do with threading. You'll see exactly the same problem if you write:

public class Foo
{
    int x = 10;
    int y = x;   
}

甚至更清楚：

Or even more clearly:

public class Bar
{
    object obj = this;
}

这里有轻微的分心了这个引用是隐含的 - 你要创建一个委托与这个

There's the slight distraction here that the this reference is implicit - you're creating a delegate with a target of this.

的目标。解决办法就是把分配到构造：

The solution is just to put the assignment into the constructor:

public Thread scrape;
public About about = new About();
public Form1()
{
    InitializeComponent();
    scrape = new Thread(scrapeStart);
}

顺便说一句：

As an aside:

• 请不要使用公共领域！


• 请遵守.NET命名约定


• 您会也的需要修改 scrapeStart 的螺纹部分，不应该访问的UI元素直接

• Please don't use public fields!
• Please adhere to .NET naming conventions
• You'll also need to fix the threading parts of scrapeStart, which shouldn't be accessing UI elements directly

这篇关于线程在C＃中的问题（A字段初始不能引用非静态字段，ECT）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！