blocks|key|1301948|text|我使用以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1301949|double+x+=+Math.Truncate(myDoubleValue+*+100)+/+100;|code-block|syntax|javascript|1301950|例如：|1301951|如果数字是50.947563，并且您使用以下命令，则会发生以下情况：|1301952|-+Math.Truncate(50.947563+*+100)+/+100;
-+Math.Truncate(5094.7563)+/+100;
-+5094+/+100
-+50.94|1301953|这就是你的答案被截断了，现在要格式化字符串，只需执行以下操作：|1301954|string+s+=+string.Format("{0:N2}%25",+x);+//+No+fear+of+rounding+and+takes+the+default+number+format|1301955|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|Y|8|@]|9|@]|A|$E|F]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

I use the following:

<pre><code>double x = Math.Truncate(myDoubleValue * 100) / 100;
</code></pre>

For instance:

If the number is 50.947563 and you use the following, the following will happen:

<pre><code>- Math.Truncate(50.947563 * 100) / 100;
- Math.Truncate(5094.7563) / 100;
- 5094 / 100
- 50.94
</code></pre>

And there's your answer truncated, now to format the string simply do the following:

<pre><code>string s = string.Format("{0:N2}%", x); // No fear of rounding and takes the default number format
</code></pre>

blocks|key|1086858|text|我建议您先截断，然后格式化：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1086859|double+a+=+123.4567;
double+aTruncated+=+Math.Truncate(a+*+100)+/+100;
CultureInfo+ci+=+new+CultureInfo("de-DE");
string+s+=+string.Format(ci,+"{0:0.00}%25",+aTruncated);|code-block|syntax|javascript|1086860|对于2位数截断，使用常量100；在小数点后使用1后跟任意数量的零。使用调整格式结果所需的区域性名称。|1086861|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I suggest you truncate first, and then format:

<pre><code>double a = 123.4567;
double aTruncated = Math.Truncate(a * 100) / 100;
CultureInfo ci = new CultureInfo("de-DE");
string s = string.Format(ci, "{0:0.00}%", aTruncated);
</code></pre>

Use the constant 100 for 2 digits truncate; use a 1 followed by as many zeros as digits after the decimal point you would like. Use the culture name you need to adjust the formatting result.

blocks|key|1302131|text|我使用price.ToString("0.00")来获取前导0|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1302132|entityMap^0|3|M|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

i use <code>price.ToString("0.00")</code>
for getting the leading 0s

blocks|key|1302144|text|最简单的方法，使用数字格式的字符串：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302145|double+total+=+"43.257"
MessageBox.Show(total.ToString("F"));|code-block|syntax|javascript|1302146|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Simplest method, use numeric format strings:

<pre><code>double total = "43.257"
MessageBox.Show(total.ToString("F"));
</code></pre>

blocks|key|1302060|text|Kyle+Rozendo所表达的c#函数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302061|string+DecimalPlaceNoRounding(double+d,+int+decimalPlaces+=+2)
{
++++double+factor+=+Math.Pow(10,+decimalPlaces);
++++d+=+d+*+factor;
++++d+=+Math.Truncate(d);
++++d+=+d+/+factor;
++++return+string.Format("{0:N"+%2B+Math.Abs(decimalPlaces)+%2B+"}",+d);
}|code-block|syntax|javascript|1302062|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The c# function, as expressed by Kyle Rozendo:
<pre><code>string DecimalPlaceNoRounding(double d, int decimalPlaces = 2)
{
 double factor = Math.Pow(10, decimalPlaces);
 d = d * factor;
 d = Math.Truncate(d);
 d = d / factor;
 return string.Format(&quot;{0:N&quot; + Math.Abs(decimalPlaces) + &quot;}&quot;, d);
}
</code></pre>

blocks|key|1302242|text|如何添加一个要舍入然后丢弃的额外小数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302243|var+d+=+0.241534545765;
var+result1+=+d.ToString("0.###%25");

var+result2+=+result1.Remove(result1.Length+-+1);|code-block|syntax|javascript|1302244|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

How about adding one extra decimal that is to be rounded and then discarded:

<pre><code>var d = 0.241534545765;
var result1 = d.ToString("0.###%");

var result2 = result1.Remove(result1.Length - 1);
</code></pre>

blocks|key|1302046|text|这对我很有效|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302047|string+prouctPrice+=+Convert.ToDecimal(String.Format("{0:0.00}",+Convert.ToDecimal(yourString))).ToString();|code-block|syntax|javascript|1302048|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is working for me

<pre><code>string prouctPrice = Convert.ToDecimal(String.Format("{0:0.00}", Convert.ToDecimal(yourString))).ToString();
</code></pre>

blocks|key|1087135|text|我在使用Xamarin表单时遇到了这个问题，并用下面的方法解决了这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1087136|percent.ToString("0.##"%2B"%25")|code-block|syntax|javascript|1087137|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I had that problem with Xamarin Forms and solved it with this:

<pre><code>percent.ToString("0.##"+"%")
</code></pre>

blocks|key|1302094|text|我知道这是一个老帖子，但我不得不这么做。虽然这里的其他方法都有效，但我想要一种简单的方法来影响对string.format的大量调用。因此，将Math.Truncate添加到的所有调用中并不是一个好的选择。此外，由于一些格式存储在数据库中，这使情况变得更糟。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1302095|因此，我制作了一个自定义格式提供程序，它允许我向格式化字符串添加截断，例如：|1302096|string.format(new+FormatProvider(),+"{0:T}",+1.1299);+//+1.12
string.format(new+FormatProvider(),+"{0:T(3)",+1.12399);+//+1.123
string.format(new+FormatProvider(),+"{0:T(1)0,000.0",+1000.9999);+//+1,000.9|code-block|syntax|javascript|1302097|该实现非常简单，并且很容易扩展到其他需求。|1302098|public+class+FormatProvider+:+IFormatProvider,+ICustomFormatter
{
++++public+object+GetFormat(Type+formatType)
++++{
++++++++if+(formatType+==+typeof+(ICustomFormatter))
++++++++{
++++++++++++return+this;
++++++++}
++++++++return+null;
++++}

++++public+string+Format(string+format,+object+arg,+IFormatProvider+formatProvider)
++++{
++++++++if+(arg+==+null+%7C%7C+arg.GetType()+!=+typeof+(double))
++++++++{
++++++++++++try
++++++++++++{
++++++++++++++++return+HandleOtherFormats(format,+arg);
++++++++++++}
++++++++++++catch+(FormatException+e)
++++++++++++{
++++++++++++++++throw+new+FormatException(string.Format("The+format+of+'{0}'+is+invalid.",+format));
++++++++++++}
++++++++}

++++++++if+(format.StartsWith("T"))
++++++++{
++++++++++++int+dp+=+2;
++++++++++++int+idx+=+1;
++++++++++++if+(format.Length+>+1)
++++++++++++{
++++++++++++++++if+(format[1]+==+'(')
++++++++++++++++{
++++++++++++++++++++int+closeIdx+=+format.IndexOf(')');
++++++++++++++++++++if+(closeIdx+>+0)
++++++++++++++++++++{
++++++++++++++++++++++++if+(int.TryParse(format.Substring(2,+closeIdx+-+2),+out+dp))
++++++++++++++++++++++++{
++++++++++++++++++++++++++++idx+=+closeIdx+%2B+1;
++++++++++++++++++++++++}
++++++++++++++++++++}
++++++++++++++++++++else
++++++++++++++++++++{
++++++++++++++++++++++++throw+new+FormatException(string.Format("The+format+of+'{0}'+is+invalid.",+format));
++++++++++++++++++++}
++++++++++++++++}
++++++++++++}
++++++++++++double+mult+=+Math.Pow(10,+dp);
++++++++++++arg+=+Math.Truncate((double)arg+*+mult)+/+mult;
++++++++++++format+=+format.Substring(idx);
++++++++}

++++++++try
++++++++{
++++++++++++return+HandleOtherFormats(format,+arg);
++++++++}
++++++++catch+(FormatException+e)
++++++++{
++++++++++++throw+new+FormatException(string.Format("The+format+of+'{0}'+is+invalid.",+format));
++++++++}
++++}

++++private+string+HandleOtherFormats(string+format,+object+arg)
++++{
++++++++if+(arg+is+IFormattable)
++++++++{
++++++++++++return+((IFormattable)+arg).ToString(format,+CultureInfo.CurrentCulture);
++++++++}
++++++++return+arg+!=+null+?+arg.ToString()+:+String.Empty;
++++}
}|1302099|entityMap^0|1C|D|1Z|D|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

I know this is a old thread but I've just had to do this. While the other approaches here work, I wanted an easy way to be able to affect a lot of calls to <code>string.format</code>. So adding the <code>Math.Truncate</code> to all the calls to wasn't really a good option. Also as some of the formatting is stored in a database, it made it even worse.

Thus, I made a custom format provider which would allow me to add truncation to the formatting string, eg:

<pre><code>string.format(new FormatProvider(), "{0:T}", 1.1299); // 1.12
string.format(new FormatProvider(), "{0:T(3)", 1.12399); // 1.123
string.format(new FormatProvider(), "{0:T(1)0,000.0", 1000.9999); // 1,000.9
</code></pre>

The implementation is pretty simple and is easily extendible to other requirements.

<pre><code>public class FormatProvider : IFormatProvider, ICustomFormatter
{
 public object GetFormat(Type formatType)
 {
 if (formatType == typeof (ICustomFormatter))
 {
 return this;
 }
 return null;
 }

 public string Format(string format, object arg, IFormatProvider formatProvider)
 {
 if (arg == null || arg.GetType() != typeof (double))
 {
 try
 {
 return HandleOtherFormats(format, arg);
 }
 catch (FormatException e)
 {
 throw new FormatException(string.Format("The format of '{0}' is invalid.", format));
 }
 }

 if (format.StartsWith("T"))
 {
 int dp = 2;
 int idx = 1;
 if (format.Length &gt; 1)
 {
 if (format[1] == '(')
 {
 int closeIdx = format.IndexOf(')');
 if (closeIdx &gt; 0)
 {
 if (int.TryParse(format.Substring(2, closeIdx - 2), out dp))
 {
 idx = closeIdx + 1;
 }
 }
 else
 {
 throw new FormatException(string.Format("The format of '{0}' is invalid.", format));
 }
 }
 }
 double mult = Math.Pow(10, dp);
 arg = Math.Truncate((double)arg * mult) / mult;
 format = format.Substring(idx);
 }

 try
 {
 return HandleOtherFormats(format, arg);
 }
 catch (FormatException e)
 {
 throw new FormatException(string.Format("The format of '{0}' is invalid.", format));
 }
 }

 private string HandleOtherFormats(string format, object arg)
 {
 if (arg is IFormattable)
 {
 return ((IFormattable) arg).ToString(format, CultureInfo.CurrentCulture);
 }
 return arg != null ? arg.ToString() : String.Empty;
 }
}
</code></pre>

blocks|key|1302264|text|为了显示货币，您可以使用"C"|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1302265|double+cost+=+1.99;
m_CostText.text+=+cost.ToString("C");+/*C:+format+as+currentcy+*/|code-block|syntax|javascript|1302266|输出：$1.99|1302267|entityMap^0|C|3|0|0|3|5|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

To what is worth, for showing currency, you can use <code>"C"</code>:

<pre><code>double cost = 1.99;
m_CostText.text = cost.ToString("C"); /*C: format as currentcy */
</code></pre>

Output: <code>$1.99</code>

blocks|key|1302203|text|以下内容只能用于使用String属性的显示。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302204|double+value+=+123.456789;
String.Format("{0:0.00}",+value);|code-block|syntax|javascript|1302205|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Following can be used for display only which uses the property of String ..

<pre><code>double value = 123.456789;
String.Format("{0:0.00}", value);
</code></pre>

How do I format a <code>Double</code> to a <code>String</code> in C# so as to have only two decimal places? 

If I use <code>String.Format("{0:0.00}%", myDoubleValue)</code> the number is then rounded and I want a simple truncate without any rounding. I also want the conversion to <code>String</code> to be culture sensitive.

C# Double - ToString() formatting with two decimal places but no rounding

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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如何在C#中将Double格式化为String，使其只有两个小数位？如果我使用String.Format("{0:0.00}%", myDoubleValue)，然后对数字进行四舍五入，我想要一个简单的截断而不进行任何四舍五入。我还希望到String的转换是文化敏感的。

问C# Double - ToString()格式，有两个小数位，但不四舍五入
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回答 11

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问C# Double - ToString()格式，有两个小数位，但不四舍五入EN

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问C# Double - ToString()格式，有两个小数位，但不四舍五入
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