C#控制台-如何在没有换行的情况下读取Line()?(或撤消\ n或垂直\ b) [英] C# Console - How to ReadLine() without a new line? ( or undo a \n or a vertical \b)

问题描述

我想知道当我处于下一行的开头时是否可以返回到最后一行?(当然，在C#控制台中)

I want to know if it is possible to get back to the last line when I'm at the beginning of the next line? (in C# Console, of course)

我的意思是 Console.WriteLine()导致转到下一行，即使按Enter键，我也希望停留在我的行中.(而且我认为没有进入下一行的另一种方法来读行，是吗?)

I mean Console.WriteLine() cause going to the next line and I want to stay in my line even after pressing enter. (And I think there isn't another way to ReadLine without going to the next line , is there?)

我发现 Console.SetCursorPosition()可能很有用，如下所示:

I found that Console.SetCursorPosition() can be useful, like below:

        int x, y;
        Console.WriteLine("Please enter the point's coordinates in this form (x,y):");
        Console.Write("(");
        x = Convert.ToInt32(Console.ReadLine());
        Console.SetCursorPosition(x.ToString().Length + 1, Console.CursorTop - 1);
        Console.Write(",");
        y = Convert.ToInt32(Console.ReadLine());
        Console.SetCursorPosition(x.ToString().Length + y.ToString().Length + 2, Console.CursorTop - 1);
        Console.WriteLine(")");

这似乎工作正常，但是当我尝试更改 Console.Write((") ;;变成类似 Console.Write("Point A =("​​)之类的东西，我需要每次更改 Console.SetCursorPosition()参数.

This seems to work fine but when I try to change Console.Write("("); into something like Console.Write("Point A=("), I need to change the the Console.SetCursorPosition() arguments every time.

如果将光标移动到控制台缓冲区中的最后一个字符(空格除外)，这也将非常有帮助.(我认为将控制台中的特定行复制到字符串中会很容易.)

Also it would be very helpful if I could move the cursor to the last character (except spaces) in the console buffer.(I think it would be easy if I could copy a specific line from console into a string.)

谢谢.

推荐答案

如何使用适合您特定用例并有助于使代码逻辑更具可读性的简单帮助器类.

How about using a simple helper class that fits your specific use case and helps make your code logic a bit more readable.

public class Prompt
{
    public struct CursorPosition
    {
        public int CursorLeft;
        public int CursorTop;
    }

    private CursorPosition _savedPosition;

    public Prompt Write(string prompt)
    {
        Console.Write(prompt);
        return this;
    }

    public Prompt Write(string promptFormat, params object[] args)
    {
        return Write(string.Format(promptFormat, args));
    }

    public Prompt WriteLine(string prompt)
    {
        Write(prompt);
        Console.WriteLine();
        return this;
    }

    public Prompt WriteLine(string promptFormat, params object[] args)
    {
        return WriteLine(string.Format(promptFormat, args));
    }

    public string ReadLine(bool advanceCursorOnSameLine = false, bool eraseLine = false)
    {
        if (advanceCursorOnSameLine || eraseLine)
        {
            SavePosition();
            if (eraseLine)
                WriteLine(new string(' ', Console.WindowWidth - _savedPosition.CursorLeft)).RestorePosition();
        }
        var input = Console.ReadLine();
        if (advanceCursorOnSameLine)
            RestorePosition(input.Length);
        return input;
    }

    public Prompt SavePosition()
    {
        _savedPosition = GetCursorPosition();
        return this;
    }

    public CursorPosition GetCursorPosition()
    {
        return new CursorPosition {
            CursorLeft = Console.CursorLeft,
            CursorTop = Console.CursorTop
        };
    }

    public Prompt RestorePosition(CursorPosition position, int deltaLeft = 0, int deltaTop = 0)
    {
        var left = Math.Min(Console.BufferWidth - 1, Math.Max(0, position.CursorLeft + deltaLeft));
        var right = Math.Min(Console.BufferHeight - 1, Math.Max(0, position.CursorTop + deltaTop));
        Console.SetCursorPosition(left, right);
        return this;
    }

    public Prompt RestorePosition(int deltaLeft = 0, int deltaTop = 0)
    {
        return RestorePosition(_savedPosition, deltaLeft, deltaTop);
    }
}

然后可以这样使用:

class Program
{
    public static void Main(params string[] args)
    {
        int x, y;
        var prompt = new Prompt();
        prompt.WriteLine("Please enter the point's coordinates in this form (x,y):");
        var savedPos = prompt.GetCursorPosition();
        while (true)
        {
            x = Convert.ToInt32(prompt.Write("(").ReadLine(true, true));
            y = Convert.ToInt32(prompt.Write(",").ReadLine(true));
            prompt.WriteLine(")");
            // do something with x and y

            var again = prompt.Write("More (Y):").ReadLine(true, true);
            if (!again.StartsWith("Y", StringComparison.OrdinalIgnoreCase))
                break;
            prompt.RestorePosition(savedPos);
        }
    }
}

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