我如何将字符串中的负浮点数转换为C#中的负浮点数?

时间:2018-10-12 17:24:29

标签: c# string exception runtime-error formatexception

我有一个浮点数为负的字符串,它看起来像这样:

-1.0

我需要将其转换为float,所以它必须是:

-1.0f

我尝试过:

bool isNegative = false; //float in my string isnt a negative
string mystr = "-1.0"; //my string
float myfloat = 0.0f; //my float

if(mystr.Contains("-")) 
{ 
    isNegative = true; 
    mystr.Replace("-"); 
} //if my string is negative,set a bool to true,and remove - from string

if(isNegative==true) 
{ 
    myfloat = float.Parse(mystr) * -1.0 
} //if bool is true(is says number in string is negative),parse string to float and make it negative
else 
{ 
    myfloat = float.Parse(mystr) 
} //if bool is false(number in string isnt negative),just parse a number

我认为该代码有效,但是它抛出了System.FormatException,所以我认为我得到了这种理解,因为代码无法用point(.)解析字符串。我在{ {1}}方法。

如果您愿意,我将显示完整的代码,如果出现错误,上部的代码只是我的真实代码的概念,有真实的代码:

float.Parse

在评论后,我将代码编辑为此:

bool redNeg = false; //red number isnt negative
bool greenNeg = false; //blue number isnt negative
bool blueNeg = false; //green number isnt negative
string[] args = GetArgs.ExtractArguments(LineText); //get strings from "translate(0.0,0.0,-1.0);"
string red = args[0]; //string1,default is 0.0
string green = args[1]; //string2,default is 0.0
string blue = args[2]; //string3,default is -1.0
if (red.Contains("-")) 
{ 
    redNeg = true; 
    red.Replace("-", ""); 
} //if string1 is negative,set negative bool to true and remove - from string

if (green.Contains("-")) 
{ 
    greenNeg = true; 
    green.Replace("-", ""); 
} //if string2 is negative,set negative bool to true and remove - from string

if (blue.Contains("-")) 
{ 
    blueNeg = true; 
    blue.Replace("-", ""); 
} //if string3 is negative,set negative bool to true and remove - from string

float redd = 0.0f; //default float of string1
float greenn = 0.0f; //default float of string2
float bluee = 0.0f; //default float of string3

if (redNeg==true) 
{ 
    redd = float.Parse(red) * -1.0f; 
} //if negative bool of string1 is true,set float to negative
else 
{ 
    redd = float.Parse(red); 
} //if its not,parse it

if (greenNeg == true) 
{ 
    greenn = float.Parse(red) * -1.0f; 
} //if negative bool of string2 is true,set float to negative
else 
{ 
    greenn = float.Parse(green); 
} //if its not,parse it

if (blueNeg == true) 
{ 
    bluee = float.Parse(red) * -1.0f; 
} //if negative bool of string3 is true,set float to negative
else 
{ 
    bluee = float.Parse(blue); 
} //if its not,parse it

gl.Translate((float)redd, (float)greenn,(float) bluee); //render function,dont touch it

但是我仍然有FormatException,但是现在我上了

var fmt = new NumberFormatInfo(); fmt.NegativeSign = "−"; //LineText is "translate(0.0,0.0,-1.0); string[] args = GetArgs.ExtractArguments(LineText); //get strings from "translate(0.0,0.0,-1.0);" string red = args[0]; //string1,default is 0.0 string green = args[1]; //string2,default is 0.0 string blue = args[2]; //string3,default is -1.0 float redd = float.Parse(red,fmt); //default float of string1 float greenn = float.Parse(green, fmt); //default float of string2 float bluee = float.Parse(blue, fmt); //default float of string3 gl.Translate((float)redd, (float)greenn,(float) bluee); //render function,dont touch it

这是一个带有负数的字符串。

1 个答案:

答案 0 :(得分:2)

您需要强制区域性信息对小数点使用点。 因为您计算机的区域设置可能使用逗号作为小数点。

 System.Globalization.CultureInfo ci = System.Globalization.CultureInfo.InstalledUICulture;
            System.Globalization.NumberFormatInfo ni = (System.Globalization.NumberFormatInfo)ci.NumberFormat.Clone();
            ni.NumberDecimalSeparator = ".";

            string s = "-1.0";
            var result = float.Parse(s, ni);