我们目前正在使用下面为我们的web应用程序中创建的美元值：

 的String.Format（{0：C0}，dollarValue）;
 

在这个例子中，如果dollarValue是145，然后我们会看到：$ 145。如果是-145，然后我们会看到（$ 145），而不是 - $ 145需要注意的是对我们来说，dollarValue是双重的，但它可以是任何数类型。我想。

不管怎样，我想是因为它是要么$ 145个或 - $ 145

现在，据我的研究，有可能使用的NumberFormatInfo类来做到这一点。我想不出如何使用它，我无法找到任何有效的例子。我没有看到这个问题在这里：C#创建自定义的NumberFormatInfo显示＆QUOT;免费＆QUOT;当一种货币的价值为$ 0.00包装但是从MSDN的例子联系到这个问题似乎从我真正想要做的有点不同。

我意识到，我需要做的事情如下：

 双dollarValue = -145d;
字符串myMoney = dollarValue.ToString（C0，someIFormatProvider）;
 

在这里someIFormatProvider可能类型的NumberFormatInfo的。现在，我所做的是这样的：

 的NumberFormatInfo NI =新的NumberFormatInfo（）;
ni.CurrencyNegativePattern = 1; //值1应该是指不使用括号
字符串myMoney = dollarValue.ToString（C0，NI）;
 

......，我得到一个实例是只读的异常。虽然文档为CurrencyNegativePattern物业说，你可以设置和获取价值，很显然，你不能。此外，的NumberFormatInfo是一个密封类。我不能轻易地创建基于关闭它一个新的类，并覆盖值。

我在一个不知如何处理这个问题。现在，我的解决方法是只否定我的负值，并有一个积极的结果，我的的String.Format（...）再这样做。是的，我知道有一个在这方面没有任何负面的迹象，但是，当然，这是很容易加入解决了 - 的结果需要前面

会有人能为我提供了如何有效地正确使用NumbefFormatInfo类在这种情况下工作的例子吗？谢谢你。

 双dollarValue = -145d;
 System.Globalization.CultureInfo modCulture =新System.Globalization.CultureInfo（EN-US）;
 字符串mymoney = dollarValue.ToString（C，modCulture）;
          的MessageBox.show（mymoney）;
 

如果您的操作系统当前区域性为en-US，那么你不需要下面的行

  System.Globalization.CultureInfo modCulture =新System.Globalization.CultureInfo（EN-US）;
 

在code将

 双dollarValue = -145d;
字符串mymoney = dollarValue.ToString（C）;
 

如果你想要做的NumberFormatInfo

 双dollarValue = -145d;
System.Globalization.CultureInfo modCulture =新System.Globalization.CultureInfo（EN-US）;
     的NumberFormatInfo数= modCulture.NumberFormat;
     字符串mymoney = dollarValue.ToString（C号）;
 

另一种方式

 双dollarValue = -145d;
System.Globalization.CultureInfo modCulture =新System.Globalization.CultureInfo（EN-US）;
的NumberFormatInfo数= modCulture.NumberFormat;
字符串mymoney = dollarValue.ToString（的String.Format（C，数））;
Console.WriteLine（mymoney）;
 

We're currently using the following for creating US dollar values in our web application:

string.Format("{0:C0}", dollarValue );

In this example, if dollarValue is 145, then we'll see: $145. If it is -145, then we'll see ($145) rather than -$145. Note that for us, dollarValue is a double, but it could be any number-type. I think.

Anyway, what I want is for it to be either $145 or -$145.

Now, according to my research, it might be possible to do this using the NumberFormatInfo class. I can't figure out how to use it, and I can't find any valid example. I did see this question here: C# creating a custom NumberFormatInfo to display "Free" when a currency value is $0.00 but the example from MSDN linked to from this question seems a bit different from what I really want to do.

I realize, I will need to do something of the following:

double dollarValue = -145d;
string myMoney = dollarValue.ToString( "C0", someIFormatProvider );

where someIFormatProvider is likely of type NumberFormatInfo. Now, what I've done is this:

NumberFormatInfo ni = new NumberformatInfo();
ni.CurrencyNegativePattern = 1; // The value 1 should mean not to use parenthesis
string myMoney = dollarValue.ToString( "C0", ni );

...and I get an "Instance is Read-Only" exception. While the "documentation" for the CurrencyNegativePattern property says you can SET and GET the value, apparently, you can't. Also, NumberFormatInfo is a sealed class. I can't easily create a new class based off it and override the value.

I'm at a loss as to how to deal with this. Right now, my workaround is to just negate my negative value and have a positive result that I do the string.Format(...) again. Yes, I realize there is no negative sign in front of this, but, of course, that's easily resolved by adding a "-" in front of the result as needed.

Would someone be able to provide me with a working example of how to effectively use the NumbefFormatInfo class correctly in this situation? Thanks.

double dollarValue = -145d;
 System.Globalization.CultureInfo modCulture = new System.Globalization.CultureInfo("en-US");
 string mymoney = dollarValue.ToString("C", modCulture);
          MessageBox.Show(mymoney);

If your Operating System current culture is en-US then you dont need the following line

System.Globalization.CultureInfo modCulture = new System.Globalization.CultureInfo("en-US");

The code will be

double dollarValue = -145d;
string mymoney = dollarValue.ToString("C");

and If you want to do with NumberFormatInfo

double dollarValue = -145d; 
System.Globalization.CultureInfo modCulture = new System.Globalization.CultureInfo("en-US");
     NumberFormatInfo number = modCulture.NumberFormat;
     string mymoney = dollarValue.ToString("C", number);

another way

double dollarValue = -145d;
System.Globalization.CultureInfo modCulture = new System.Globalization.CultureInfo("en-US");
NumberFormatInfo number = modCulture.NumberFormat;
string mymoney = dollarValue.ToString(String.Format("C",number));
Console.WriteLine(mymoney);