C# 使用 DateTime.ToString() 时获取日期后缀
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Getting day suffix when using DateTime.ToString()
提问by Craig Bovis
Is it possible to include the day suffix when formatting a date using DateTime.ToString()?
使用 DateTime.ToString() 格式化日期时是否可以包含日期后缀？
For example I would like to print the date in the following format - Monday 27th July 2009. However the closest example I can find using DateTime.ToString() is Monday 27 July 2009.
例如，我想以以下格式打印日期 - 2009 年 7 月 27 日星期一。但是，我可以使用 DateTime.ToString() 找到的最接近的示例是 2009 年 7 月 27 日星期一。
Can I do this with DateTime.ToString() or am I going to have to fall back to my own code?
我可以用 DateTime.ToString() 来做到这一点还是我将不得不退回到我自己的代码？
采纳答案by Bryan Bailliache
As a reference I always use/refer to SteveX String Formattingand there doesn't appear to be any "th" in any of the available variables but you could easily build a string with
作为参考，我总是使用/引用SteveX String Formatting并且在任何可用变量中似乎都没有任何“th”，但是您可以轻松地构建一个字符串
string.Format("{0:dddd dd}{1} {0:MMMM yyyy}", DateTime.Now, (?));
You would then have to supply a "st" for 1, "nd" for 2, "rd" for 3, and "th" for all others and could be in-lined with a "? :" statement.
然后，您必须为 1 提供“st”，为 2 提供“nd”，为 3 提供“rd”，并为所有其他提供“th”，并且可以与“？：”语句内联。
var now = DateTime.Now;
(now.Day % 10 == 1 && now.Day != 11) ? "st"
: (now.Day % 10 == 2 && now.Day != 12) ? "nd"
: (now.Day % 10 == 3 && now.Day != 13) ? "rd"
: "th"
回答by GxG
in the MSDN documentation there is no reference to a culture that could convert that 17 into 17th. so You should do it manually via code-behind.Or build one...you could build a function that does that.
在 MSDN 文档中，没有提到可以将 17 转换为 17 的文化。所以你应该通过代码隐藏手动完成。或者构建一个......你可以构建一个这样做的函数。
public string CustomToString(this DateTime date)
{
string dateAsString = string.empty;
<here wright your code to convert 17 to 17th>
return dateAsString;
}
回答by Piotr Lewandowski
Here is extended version including 11th, 12th and 13th:
这是扩展版本，包括第 11、12 和 13 日：
DateTime dt = DateTime.Now;
string d2d = dt.ToString("dd").Substring(1);
string daySuffix =
(dt.Day == 11 || dt.Day == 12 || dt.Day == 13) ? "th"
: (d2d == "1") ? "st"
: (d2d == "2") ? "nd"
: (d2d == "3") ? "rd"
: "th";
回答by Anthony Walsh
Another option is using the Modulo Operator:
另一种选择是使用模运算符：
public string CreateDateSuffix(DateTime date)
{
// Get day...
var day = date.Day;
// Get day modulo...
var dayModulo = day%10;
// Convert day to string...
var suffix = day.ToString(CultureInfo.InvariantCulture);
// Combine day with correct suffix...
suffix += (day == 11 || day == 12 || day == 13) ? "th" :
(dayModulo == 1) ? "st" :
(dayModulo == 2) ? "nd" :
(dayModulo == 3) ? "rd" :
"th";
// Return result...
return suffix;
}
You would then call the above method by passing-in a DateTimeobject as a parameter, for example:
然后，您可以通过传入DateTime对象作为参数来调用上述方法，例如：
// Get date suffix for 'October 8th, 2019':
var suffix = CreateDateSuffix(new DateTime(2019, 10, 8));
For more info about the DateTimeconstructor, please see Microsoft Docs Page.
有关DateTime构造函数的详细信息，请参阅Microsoft Docs 页。
回答by Lazlow
Another option using switch:
使用 switch 的另一种选择：
string GetDaySuffix(int day)
{
switch (day)
{
case 1:
case 21:
case 31:
return "st";
case 2:
case 22:
return "nd";
case 3:
case 23:
return "rd";
default:
return "th";
}
}
回答by Jodda
Another option using the last string character:
使用最后一个字符串字符的另一个选项：
public static string getDayWithSuffix(int day) {
string d = day.ToString();
if (day < 11 || day > 13) {
if (d.EndsWith("1")) {
d += "st";
} else if (d.EndsWith("2")) {
d += "nd";
} else if (d.EndsWith("3")) {
d += "rd";
} else {
d += "th";
} else {
d += "th";
}
return d;
}
回答by Duncan
I believe this to be a good solution, covering numbers such as 111th etc:
我相信这是一个很好的解决方案，涵盖诸如 111th 等数字：
private string daySuffix(int day)
{
if (day > 0)
{
if (day % 10 == 1 && day % 100 != 11)
return "st";
else if (day % 10 == 2 && day % 100 != 12)
return "nd";
else if (day % 10 == 3 && day % 100 != 13)
return "rd";
else
return "th";
}
else
return string.Empty;
}
回答by Tony
A cheap and cheerful VB solution:
一个便宜又愉快的 VB 解决方案：
litDate.Text = DatePart("dd", Now) & GetDateSuffix(DatePart("dd", Now))
Function GetDateSuffix(ByVal dateIn As Integer) As String
'// returns formatted date suffix
Dim dateSuffix As String = ""
Select Case dateIn
Case 1, 21, 31
dateSuffix = "st"
Case 2, 22
dateSuffix = "nd"
Case 3, 23
dateSuffix = "rd"
Case Else
dateSuffix = "th"
End Select
Return dateSuffix
End Function
回答by rashleighp
I did it like this, it gets around some of the problems given in the other examples.
我是这样做的，它解决了其他示例中给出的一些问题。
public static string TwoLetterSuffix(this DateTime @this)
{
var dayMod10 = @this.Day % 10;
if (dayMod10 > 3 || dayMod10 == 0 || (@this.Day >= 10 && @this.Day <= 19))
{
return "th";
}
else if(dayMod10 == 1)
{
return "st";
}
else if (dayMod10 == 2)
{
return "nd";
}
else
{
return "rd";
}
}
回答by Corbin Spicer
For what its worth here is my final solution using the below answers
这里的价值是我使用以下答案的最终解决方案
DateTime dt = DateTime.Now;
string d2d = dt.ToString("dd").Substring(1);
string suffix =
(dt.Day == 11 || dt.Day == 12 || dt.Day == 13) ? "th"
: (d2d == "1") ? "st"
: (d2d == "2") ? "nd"
: (d2d == "3") ? "rd"
: "th";
Date.Text = DateTime.Today.ToString("dddd d") + suffix + " " + DateTime.Today.ToString("MMMM") + DateTime.Today.ToString(" yyyy");
