如何分配foreach迭代变量？ [英] How do I assign a foreach iteration variable?

问题描述

你好，



我有

Hello,

I have a

foreach

循环运行，我想为变量赋值，但我无法。它显示了一个错误：

loop running and I want to assign values to the variable but I am unable to. It shows me an error:

cannot assign because it is a foreach iteration variable

Visual Basic中的相同代码工作正常：

The same code in Visual Basic works fine:

For Each spline As String In Regex.Split(replicFile, vbNewLine)
           Label9.Text = spline
           Me.Refresh()
           Do While spline.EndsWith(Chr(10)) Or spline.EndsWith(Chr(13))
               spline = spline.Substring(0, spline.Length - 1)
           Loop
           Do While spline.StartsWith(Chr(10)) Or spline.StartsWith(Chr(13))
               spline = spline.Substring(1, spline.Length - 1)
           Loop

请帮忙。



问候

Aman Chaurasia



我的尝试：

Please help.

Regards
Aman Chaurasia

What I have tried:

foreach (string spline in Regex.Split(replicFile, Environment.NewLine))
			{
				Label9.Text = spline;
				this.Refresh();
				while (spline.EndsWith(('\n').ToString()) || spline.EndsWith(('\r').ToString()))
				{
					spline = spline.Substring(0, spline.Length - 1);
				}
				while (spline.StartsWith(('\n').ToString()) || spline.StartsWith(('\r').ToString()))
				{
					spline = spline.Substring(1, spline.Length - 1);
				}

推荐答案

使用第二个变量：

Use a second variable:

foreach (string s in Regex.Split(replicFile, Environment.NewLine))
{
    string spline = s;
    
    Label9.Text = spline;
    this.Refresh();
    
    while (spline.EndsWith(('\n').ToString()) || spline.EndsWith(('\r').ToString()))
    {
        spline = spline.Substring(0, spline.Length - 1);
    }
    while (spline.StartsWith(('\n').ToString()) || spline.StartsWith(('\r').ToString()))
    {
        spline = spline.Substring(1, spline.Length - 1);
    }

注意：您可以在循环时替换这两个只需一次调用 String.Trim [ ^ ]：



NB: You can replace both of those while loops with a single call to String.Trim[^]:

foreach (string s in Regex.Split(replicFile, Environment.NewLine))
{
    string spline = s;
    
    Label9.Text = spline;
    this.Refresh();
    
    spline = spline.Trim(new[] { '\r', '\n' });

你必须使用等价的

for (int i=0; i< ;++) {}

或

while

循环，如果你想在循环时操纵集合。



Foreach不支持您的用例。

loop if you want to manipulate the collection while you loop over it.

Foreach does not support your use case.

这篇关于如何分配foreach迭代变量？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！