C# 如何将字符串转换为布尔值

how to convert a string to a bool

提问by Sachin Kainth

I have a stringthat can be either "0" or "1", and it is guaranteed that it won't be anything else.

我有一个string可以是“0”或“1”的，并且可以保证它不会是其他任何东西。

So the question is: what's the best, simplest and most elegant way to convert this to a bool?

所以问题是：将它转换为 a 的最佳、最简单和最优雅的方法是bool什么？

采纳答案by Kendall Frey

Quite simple indeed:

确实很简单：

bool b = str == "1";

回答by GETah

bool b = str.Equals("1")? true : false;

Or even better, as suggested in a comment below:

或者甚至更好，如以下评论中所建议：

bool b = str.Equals("1");

回答by Mohammad Sepahvand

Ignoring the specific needs of this question, and while its never a good idea to cast a string to a bool, one way would be to use the ToBoolean()method on the Convert class:

忽略这个问题的特定需求，虽然将字符串转换为 bool 从来都不是一个好主意，但一种方法是在 Convert 类上使用ToBoolean()方法：

bool val = Convert.ToBoolean("true");

bool val = Convert.ToBoolean("true");

or an extension method to do whatever weird mapping you're doing:

或者一个扩展方法来做你正在做的任何奇怪的映射：

public static class StringExtensions
{
    public static bool ToBoolean(this string value)
    {
        switch (value.ToLower())
        {
            case  "true":
                return true;
            case "t":
                return true;
            case "1":
                return true;
            case "0":
                return false;
            case "false":
                return false;
            case "f":
                return false;
            default:
                throw new InvalidCastException("You can't cast that value to a bool!");
        }
    }
}

回答by mcfea

I made something a little bit more extensible, Piggybacking on Mohammad Sepahvand's concept:

我做了一些更可扩展的东西，捎带在 Mohammad Sepahvand 的概念上：

    public static bool ToBoolean(this string s)
    {
        string[] trueStrings = { "1", "y" , "yes" , "true" };
        string[] falseStrings = { "0", "n", "no", "false" };


        if (trueStrings.Contains(s, StringComparer.OrdinalIgnoreCase))
            return true;
        if (falseStrings.Contains(s, StringComparer.OrdinalIgnoreCase))
            return false;

        throw new InvalidCastException("only the following are supported for converting strings to boolean: " 
            + string.Join(",", trueStrings)
            + " and "
            + string.Join(",", falseStrings));
    }

回答by live-love

I know this doesn't answer your question, but just to help other people. If you are trying to convert "true" or "false" strings to boolean:

我知道这不能回答你的问题，只是为了帮助其他人。如果您尝试将“true”或“false”字符串转换为布尔值：

Try Boolean.Parse

尝试 Boolean.Parse

bool val = Boolean.Parse("true"); ==> true
bool val = Boolean.Parse("True"); ==> true
bool val = Boolean.Parse("TRUE"); ==> true
bool val = Boolean.Parse("False"); ==> false
bool val = Boolean.Parse("1"); ==> Exception!
bool val = Boolean.Parse("diffstring"); ==> Exception!

回答by Mark Meuer

Here's my attempt at the most forgiving string to bool conversion that is still useful, basically keying off only the first character.

这是我尝试最宽容的字符串到布尔转换仍然有用，基本上只关闭第一个字符。

public static class StringHelpers
{
    /// <summary>
    /// Convert string to boolean, in a forgiving way.
    /// </summary>
    /// <param name="stringVal">String that should either be "True", "False", "Yes", "No", "T", "F", "Y", "N", "1", "0"</param>
    /// <returns>If the trimmed string is any of the legal values that can be construed as "true", it returns true; False otherwise;</returns>
    public static bool ToBoolFuzzy(this string stringVal)
    {
        string normalizedString = (stringVal?.Trim() ?? "false").ToLowerInvariant();
        bool result = (normalizedString.StartsWith("y") 
            || normalizedString.StartsWith("t")
            || normalizedString.StartsWith("1"));
        return result;
    }
}

回答by yogihosting

I used the below code to convert a string to boolean.

我使用以下代码将字符串转换为布尔值。

Convert.ToBoolean(Convert.ToInt32(myString));

回答by Outside the Box Developer

    private static readonly ICollection<string> PositiveList = new Collection<string> { "Y", "Yes", "T", "True", "1", "OK" };

public static bool ToBoolean(this string input)
{
                return input != null && PositiveList.Any(λ => λ.Equals(input, StringComparison.OrdinalIgnoreCase));
}

回答by Arvo Bowen

I love extension methods and this is the one I use...

我喜欢扩展方法，这是我使用的方法...

static class StringHelpers
{
    public static bool ToBoolean(this String input, out bool output)
    {
        //Set the default return value
        output = false;

        //Account for a string that does not need to be processed
        if (input == null || input.Length < 1)
            return false;

        if ((input.Trim().ToLower() == "true") || (input.Trim() == "1"))
            output = true;
        else if ((input.Trim().ToLower() == "false") || (input.Trim() == "0"))
            output = false;
        else
            return false;

        //Return success
        return true;
    }
}

Then to use it just do something like...

然后使用它只是做一些像......

bool b;
bool myValue;
data = "1";
if (!data.ToBoolean(out b))
  throw new InvalidCastException("Could not cast to bool value from data '" + data + "'.");
else
  myValue = b;  //myValue is True

回答by Hoang Tran

I use this:

我用这个：

public static bool ToBoolean(this string input)
        {
            //Account for a string that does not need to be processed
            if (string.IsNullOrEmpty(input))
                return false;

            return (input.Trim().ToLower() == "true") || (input.Trim() == "1");
        }