LINQ方式将包含小数的文本转换为int？ [英] A LINQ way of converting text containing decimals to int?
问题描述
参考Int32.TryParse方法： http：// msdn.microsoft.com/en-us/library/zf50za27.aspx
如果必须，特别是这个例子：
numericString = " 10345.72"
styles = NumberStyles.Integer或NumberStyles.AllowDecimalPoint
CallTryParse（numericString，styles）
哪个失败转换字符串10345.72到了int 10345，
，因为。之后的额外数字。
我的问题是：有一个整洁的LINQ吗？类型解析这样的方式
一个字符串，以便第一次。 （句号）被找到，字符串是
提取，然后我可以使用Int32.TryParse？
我知道我可以使用一个字符来解决这个问题缓冲区，读取每个
Unicode字节进入缓冲区，然后在我第一次找到一个
。时停止，然后读出缓冲区来创建一个字符串，然后使用
Int32.TryParse从字符串中提取int。也就是说，也许我可以使用StringBuilder方法将CopyTo变为char数组，然后使用
技巧在。之前提取数字字符串。 />
例如 -
StringBuilder sb = new StringBuilder（" 10345.72"）;
int count = sb.Length;
char [] temporary_charBuf1 = new char [100]; // 1 of 2
sb.Copy（0，temporary_charBuf1,0，count）;
char [] charBuf2 = new char [ 100] // 2 of 2
foreach（charc in temporary_charBuf）{//此处代码：如果char不是
期间，请填写charBuf2，否则不会在一段时间后中断}
string numericString ="" ;;
numericString = new string（charBuf2）; //创建新的字符串传递
charBuf2到构造函数中
" 10345.72。
但我正在寻找一种更快或更短的方式（因为这不是一笔很大的b
交易，而且我不是''我想花太多代码来制作
工作）。正如你从上面所看到的，它甚至不包括foreach循环中的
代码，它是很多代码。
我们可以用一行LINQ替换它（加上我正在努力学习
LINQ，因为我去）？
没什么大不了的（伪代码没问题）......好奇。
RL
Refer to Int32.TryParse method: http://msdn.microsoft.com/en-us/library/zf50za27.aspx
if you have to, specifically this example:
numericString = "10345.72"
styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
CallTryParse(numericString, styles)
Which failed to convert the string "10345.72" to the int 10345,
because of the extra digits after the "."
My question is this: is there a neat "LINQ" type way of parsing such
a string so that the first time a "." (period) is found, the string is
extracted, and then I can use Int32.TryParse?
I know I can solve this problem using a character buffer, reading each
Unicode byte into the buffer, then stopping the first time I find a
".", then reading out the buffer to create a string, then using
Int32.TryParse to extract the int from the string. That is, perhaps I
can use the StringBuilder method to CopyTo a char array, then use a
trick to extract the numeric string before the "."
For example--
StringBuilder sb = new StringBuilder ("10345.72");
int count = sb.Length;
char[] temporary_charBuf1 = new char[100]; // 1 of 2
sb.Copy(0,temporary_charBuf1,0,count);
char[] charBuf2 = new char [100] //2 of 2
foreach (char c in temporary_charBuf) {//code here: if char is not a
period, fill charBuf2, otherwise not and break once a period is found}
string numericString = "";
numericString = new string(charBuf2); // Create new string passing
charBuf2 into the constructor
Now your numericString should be 10345 from the original string
"10345.72".
But I''m looking for a faster or shorter way (since this is not a big
deal, and I don''t want to spend too many lines of code making it
work). As you can see from the above, which does not even include the
code inside the foreach loop, it''s a lot of code.
Can we replace this with one line of LINQ (plus I''m trying to learn
LINQ as I go)?
No big deal (pseudo code is OK)...just curious.
RL
推荐答案
raylopez99< ra ******** @ yahoo.comwrote：
< snip>
raylopez99 <ra********@yahoo.comwrote:
<snip>
我们可以用一行LINQ替换它（加上我''我试着学习
LINQ，因为我去了）？
没什么大不了的（伪代码还可以）......只是好奇。
Can we replace this with one line of LINQ (plus I''m trying to learn
LINQ as I go)?
No big deal (pseudo code is OK)...just curious.
你*可以*用LINQ来做，但是它会非常缓慢且
难以理解。这是一个更简单的方法：
public int ParseInt32BeforePeriod（string text）
{
int periodIndex = text .IndexOf（''。''）;
if（periodIndex！= -1）
{
text = text.Substring（0 ，periodIndex）;
}
返回int.Parse（文字）;
}
（如果你愿意的话，你可以把它转换成一个试用了
参数的TryParseInt32BeforePeriod并很容易地返回一个布尔值。）
-
Jon Skeet - < sk *** @ pobox.com>
网站： http://www.pobox.com/~skeet
Blog： http://www.msmvps.com/jon.skeet
C＃深度： http://csharpindepth.com
You *could* do it with LINQ, but it would be painfully slow and
unreadable. Here''s a simpler method to do it:
public int ParseInt32BeforePeriod(string text)
{
int periodIndex = text.IndexOf(''.'');
if (periodIndex != -1)
{
text = text.Substring(0, periodIndex);
}
return int.Parse(text);
}
(You can turn it into a TryParseInt32BeforePeriod taking an out
parameter and returning a boolean pretty easily, if you want.)
--
Jon Skeet - <sk***@pobox.com>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com
raylopez99写道：
raylopez99 wrote:
参考Int32.TryParse方法： http://msdn.microsoft.com/en-us/library/zf50za27.aspx
如果必须，特别是这个例子：
numericString =" 10345.72"
styles = NumberStyles.Integer或NumberStyles.AllowDecimalPoint
CallTryParse（numericString，styles）
未能转换字符串10345.72到了int 10345，
，因为。之后的额外数字。
我的问题是：有一个整洁的LINQ吗？类型解析这样的方式
一个字符串，以便第一次。 （句号）被找到，字符串是
提取，然后我可以使用Int32.TryParse？
Refer to Int32.TryParse method: http://msdn.microsoft.com/en-us/library/zf50za27.aspx
if you have to, specifically this example:
numericString = "10345.72"
styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
CallTryParse(numericString, styles)
Which failed to convert the string "10345.72" to the int 10345,
because of the extra digits after the "."
My question is this: is there a neat "LINQ" type way of parsing such
a string so that the first time a "." (period) is found, the string is
extracted, and then I can use Int32.TryParse?
int result =（int）Math.Floor（decimal.Parse（" 10345.72"））;
Alun Harford
int result = (int)Math.Floor(decimal.Parse("10345.72"));
Alun Harford
Alun Harford写道：
Alun Harford wrote:
> ;
int result =（int）Math.Floor（decimal.Parse（" 10345.72"））;
>
int result = (int)Math.Floor(decimal.Parse("10345.72"));
Cripes，is那合法吗？我的gawd，是的。那太棒了。
RL
Cripes, is that legal? My gawd, it is. That''s brilliant.
RL
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