我如何能够发现字符串值的数据类型 [英] How Do I Can Discovery Datatype Of A String Value

问题描述

大家好，



a有一个字符串，我需要知道你的价值是多少。我该怎么办？

Hello guys,

a have a string and i need to know if your value is a number. how i can do this?

string myString = "1";
//is a string but your value is a number.

谢谢

thanks

推荐答案

你必须检查值是否可以解释为布尔值或整数或其他...

http： //msdn.microsoft.com/en-us/library/system.boolean.tryparse(v=vs.110).aspx [ ^ ]

http://msdn.microsoft.com/en-us/library/system。 int32.tryparse（v = vs.110）.aspx [ ^ ]

http://msdn.microsoft.com/en-us/library/system.double.tryparse(v = vs.110）.aspx [ ^ ]

You have to check if value can be interpreted as Boolean or Integer or other...
http://msdn.microsoft.com/en-us/library/system.boolean.tryparse(v=vs.110).aspx[^]
http://msdn.microsoft.com/en-us/library/system.int32.tryparse(v=vs.110).aspx[^]
http://msdn.microsoft.com/en-us/library/system.double.tryparse(v=vs.110).aspx[^]

离开我的头顶，你总是可以实现蛮力的方法来测试字符串条目 - 我刚刚在记事本中敲了这个但是理论是合理的：

Off the top of my head, you could always implement the brute force approach to testing the string entry - I've just knocked this up in Notepad but the theory is sound:

public static class ConverterExtensions
{
  public static bool IsNumber(this string source)
  {
    if (string.IsNullOrWhitespace(source)) return false;

    const Types[] types = new Type[]{ 
      typeof(short), typeof(ushort), 
      typeof(int), typeof(uint), 
      typeof(long), typeof(ulong), 
      typeof(float), typeof(double), typeof(decimal)
    };
    foreach (Type type in types)
    {
      if (source.TryChangeType(type))
        return true;
    }
    return false;
  }

  public static bool TryChangeType(this string source, Type targetType)
  {
    try
    {
      Convert.ChangeType(source, targetType);
      return true;
    }
    catch (Exception)
    {
      return false;
    }
  }
}

string myString = "1";
int intVal = 0;
if(int.TryParse(myString, out intVal))
{

}

int.TryParse 

将返回true。

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