关于CString TrimLeft

最新推荐文章于 2024-01-30 07:00:00 发布
最新推荐文章于 2024-01-30 07:00:00 发布
阅读量760 收藏
点赞数
CC 4.0 BY-SA版权
分类专栏： C++ 个人心得 编程 软件
版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
本文链接：https://blog.youkuaiyun.com/mcgradycom2/article/details/7389556
本文解释了TrimLeft()函数的工作原理，通过实例演示如何在目标字符串中删除指定的前缀字符，最终得到的字符串结果为F，而非RF。分享学习心得，促进技术交流。

摘要生成于 C知道 ，由 DeepSeek-R1 满血版支持， 前往体验 >

以前一直对TrimLeft（）没有特别注意；
比如：
CString str = "MR,RF";
str = str.TrimLeft("MR,");
我们会得到什么结果？？

以前以为是RF，但结果却是 str = “F”；


why？


原来是TrimLeft是在目标字符串中区搜索要删除的字符串入“MR,”中有的字符，直到第一个要删除字符串中没有的字符“F”；

啊，原来如此~~希望大家有学习的心得可以互相学习！

CString::TrimLeft和CString::TrimRight
Gordennizaicunzai的博客
10-30 1987
CString::TrimLeft void TrimLeft( );当在没有参数的情况下调用时，TrimLeft删除字符串最前面的换行符，空格和tab字符。 void CString::TrimLeft( TCHAR chTarget ); void CString::TrimLeft( LPCTSTR lpszTargets ); Parameters chTarget The t
MFC中CString类常用函数介绍
Veis的博客
04-10 1668
CString类的介绍（宽字符形式介绍） 文章目录CString类的介绍（宽字符形式介绍）1、CString类原型2、常见构造函数的使用3、AppendFormat函数4、Compare和CompareNoCase函数5、Delete函数6、Find函数7、FindOneOf函数8、Format函数9、GetEnvironmentVariable函数10、Insert函数11、Left、Right...
一个跨平台的CString源码
10-15
// ============================================================================= // FILE: StdString.h // AUTHOR: Joe O'Leary (with outside help noted in comments) // // If you find any bugs in this code, please let me know: // // jmoleary@earthlink.net // http://www.joeo.net/stdstring.htm (a bit outdated) // // The latest version of this code should always be available at the // following link: // // http://www.joeo.net/code/StdString.zip (Dec 6, 2003) // // // REMARKS: // This header file declares the CStdStr template. This template derives // the Standard C++ Library basic_string<> template and add to it the // the following conveniences: // - The full MFC CString set of functions (including implicit cast) // - writing to/reading from COM IStream interfaces // - Functional objects for use in STL algorithms // // From this template, we intstantiate two classes: CStdStringA and // CStdStringW. The name "CStdString" is just a #define of one of these, // based upone the UNICODE macro setting // // This header also declares our own version of the MFC/ATL UNICODE-MBCS // conversion macros. Our version looks exactly like the Microsoft's to // facilitate portability. // // NOTE: // If you you use this in an MFC or ATL build, you should include either // afx.h or atlbase.h first, as appropriate. // // PEOPLE WHO HAVE CONTRIBUTED TO THIS CLASS: // // Several people have helped me iron out problems and othewise improve // this class. OK, this is a long list but in my own defense, this code // has undergone two major rewrites. Many of the improvements became // necessary after I rewrote the code as a template. Others helped me // improve the CString facade. // // Anyway, these people are (in chronological order): // // - Pete the Plumber (???) // - Julian Selman // - Chris (of Melbsys) // - Dave Plummer // - John C Sipos // - Chris Sells // - Nigel Nunn // - Fan Xia // - Matthew Williams // - Carl Engman // - Mark Zeren // - Craig Watson // - Rich Zuris // - Karim Ratib // - Chris Conti // - Baptiste Lepilleur // - Greg Pickles // - Jim Cline // - Jeff Kohn // - Todd Heckel // - Ullrich Poll?hne // - Joe Vitaterna // - Joe Woodbury // - Aaron (no last name) // - Joldakowski (???) // - Scott Hathaway // - Eric Nitzche // - Pablo Presedo // - Farrokh Nejadlotfi // - Jason Mills // - Igor Kholodov // - Mike Crusader // - John James // - Wang Haifeng // - Tim Dowty // - Arnt Witteveen // - Glen Maynard // - Paul DeMarco // - Bagira (full name?) // - Ronny Schulz // - Jakko Van Hunen // - Charles Godwin // - Henk Demper // - Greg Marr // - Bill Carducci // - Brian Groose // - MKingman // - Don Beusee // // REVISION HISTORY // // 2005-JAN-10 - Thanks to Don Beusee for pointing out the danger in mapping // length-checked formatting functions to non-length-checked // CRT equivalents. Also thanks to him for motivating me to // optimize my implementation of Replace() // // 2004-APR-22 - A big, big thank you to "MKingman" (whoever you are) for // finally spotting a silly little error in StdCodeCvt that // has been causing me (and users of CStdString) problems for // years in some relatively rare conversions. I had reversed // two length arguments. // // 2003-NOV-24 - Thanks to a bunch of people for helping me clean up many // compiler warnings (and yes, even a couple of actual compiler // errors). These include Henk Demper for figuring out how // to make the Intellisense work on with CStdString on VC6, // something I was never able to do. Greg Marr pointed out // a compiler warning about an unreferenced symbol and a // problem with my version of Load in MFC builds. Bill // Carducci took a lot of time with me to help me figure out // why some implementations of the Standard C++ Library were // returning error codes for apparently successful conversions // between ASCII and UNICODE. Finally thanks to Brian Groose // for helping me fix compiler signed unsigned warnings in // several functions. // // 2003-JUL-10 - Thanks to Charles Godwin for making me realize my 'FmtArg' // fixes had inadvertently broken the DLL-export code (which is // normally commented out. I had to move it up higher. Also // this helped me catch a bug in ssicoll that would prevent // compilation, otherwise. // // 2003-MAR-14 - Thanks to Jakko Van Hunen for pointing out a copy-and-paste // bug in one of the overloads of FmtArg. // // 2003-MAR-10 - Thanks to Ronny Schulz for (twice!) sending me some changes // to help CStdString build on SGI and for pointing out an // error in placement of my preprocessor macros for ssfmtmsg. // // 2002-NOV-26 - Thanks to Bagira for pointing out that my implementation of // SpanExcluding was not properly handling the case in which // the string did NOT contain any of the given characters // // 2002-OCT-21 - Many thanks to Paul DeMarco who was invaluable in helping me // get this code working with Borland's free compiler as well // as the Dev-C++ compiler (available free at SourceForge). // // 2002-SEP-13 - Thanks to Glen Maynard who helped me get rid of some loud // but harmless warnings that were showing up on g++. Glen // also pointed out that some pre-declarations of FmtArg<> // specializations were unnecessary (and no good on G++) // // 2002-JUN-26 - Thanks to Arnt Witteveen for pointing out that I was using // static_cast<> in a place in which I should have been using // reinterpret_cast<> (the ctor for unsigned char strings). // That's what happens when I don't unit-test properly! // Arnt also noticed that CString was silently correcting the // 'nCount' argument to Left() and Right() where CStdString was // not (and crashing if it was bad). That is also now fixed! // // 2002-FEB-25 - Thanks to Tim Dowty for pointing out (and giving me the fix // for) a conversion problem with non-ASCII MBCS characters. // CStdString is now used in my favorite commercial MP3 player! // // 2001-DEC-06 - Thanks to Wang Haifeng for spotting a problem in one of the // assignment operators (for _bstr_t) that would cause compiler // errors when refcounting protection was turned off. // // 2001-NOV-27 - Remove calls to operator!= which involve reverse_iterators // due to a conflict with the rel_ops operator!=. Thanks to // John James for pointing this out. // // 2001-OCT-29 - Added a minor range checking fix for the Mid function to // make it as forgiving as CString's version is. Thanks to // Igor Kholodov for noticing this. // - Added a specialization of std::swap for CStdString. Thanks // to Mike Crusader for suggesting this! It's commented out // because you're not supposed to inject your own code into the // 'std' namespace. But if you don't care about that, it's // there if you want it // - Thanks to Jason Mills for catching a case where CString was // more forgiving in the Delete() function than I was. // // 2001-JUN-06 - I was violating the Standard name lookup rules stated // in [14.6.2(3)]. None of the compilers I've tried so // far apparently caught this but HP-UX aCC 3.30 did. The // fix was to add 'this->' prefixes in many places. // Thanks to Farrokh Nejadlotfi for this! // // 2001-APR-27 - StreamLoad was calculating the number of BYTES in one // case, not characters. Thanks to Pablo Presedo for this. // // 2001-FEB-23 - Replace() had a bug which caused infinite loops if the // source string was empty. Fixed thanks to Eric Nitzsche. // // 2001-FEB-23 - Scott Hathaway was a huge help in providing me with the // ability to build CStdString on Sun Unix systems. He // sent me detailed build reports about what works and what // does not. If CStdString compiles on your Unix box, you // can thank Scott for it. // // 2000-DEC-29 - Joldakowski noticed one overload of Insert failed to do a // range check as CString's does. Now fixed -- thanks! // // 2000-NOV-07 - Aaron pointed out that I was calling static member // functions of char_traits via a temporary. This was not // technically wrong, but it was unnecessary and caused // problems for poor old buggy VC5. Thanks Aaron! // // 2000-JUL-11 - Joe Woodbury noted that the CString::Find docs don't match // what the CString::Find code really ends up doing. I was // trying to match the docs. Now I match the CString code // - Joe also caught me truncating strings for GetBuffer() calls // when the supplied length was less than the current length. // // 2000-MAY-25 - Better support for STLPORT's Standard library distribution // - Got rid of the NSP macro - it interfered with Koenig lookup // - Thanks to Joe Woodbury for catching a TrimLeft() bug that // I introduced in January. Empty strings were not getting // trimmed // // 2000-APR-17 - Thanks to Joe Vitaterna for pointing out that ReverseFind // is supposed to be a const function. // // 2000-MAR-07 - Thanks to Ullrich Poll?hne for catching a range bug in one // of the overloads of assign. // // 2000-FEB-01 - You can now use CStdString on the Mac with CodeWarrior! // Thanks to Todd Heckel for helping out with this. // // 2000-JAN-23 - Thanks to Jim Cline for pointing out how I could make the // Trim() function more efficient. // - Thanks to Jeff Kohn for prompting me to find and fix a typo // in one of the addition operators that takes _bstr_t. // - Got rid of the .CPP file - you only need StdString.h now! // // 1999-DEC-22 - Thanks to Greg Pickles for helping me identify a problem // with my implementation of CStdString::FormatV in which // resulting string might not be properly NULL terminated. // // 1999-DEC-06 - Chris Conti pointed yet another basic_string<> assignment // bug that MS has not fixed. CStdString did nothing to fix // it either but it does now! The bug was: create a string // longer than 31 characters, get a pointer to it (via c_str()) // and then assign that pointer to the original string object. // The resulting string would be empty. Not with CStdString! // // 1999-OCT-06 - BufferSet was erasing the string even when it was merely // supposed to shrink it. Fixed. Thanks to Chris Conti. // - Some of the Q172398 fixes were not checking for assignment- // to-self. Fixed. Thanks to Baptiste Lepilleur. // // 1999-AUG-20 - Improved Load() function to be more efficient by using // SizeOfResource(). Thanks to Rich Zuris for this. // - Corrected resource ID constructor, again thanks to Rich. // - Fixed a bug that occurred with UNICODE characters above // the first 255 ANSI ones. Thanks to Craig Watson. // - Added missing overloads of TrimLeft() and TrimRight(). // Thanks to Karim Ratib for pointing them out // // 1999-JUL-21 - Made all calls to GetBuf() with no args check length first. // // 1999-JUL-10 - Improved MFC/ATL independence of conversion macros // - Added SS_NO_REFCOUNT macro to allow you to disable any // reference-counting your basic_string<> impl. may do. // - Improved ReleaseBuffer() to be as forgiving as CString. // Thanks for Fan Xia for helping me find this and to // Matthew Williams for pointing it out directly. // // 1999-JUL-06 - Thanks to Nigel Nunn for catching a very sneaky bug in // ToLower/ToUpper. They should call GetBuf() instead of // data() in order to ensure the changed string buffer is not // reference-counted (in those implementations that refcount). // // 1999-JUL-01 - Added a true CString facade. Now you can use CStdString as // a drop-in replacement for CString. If you find this useful, // you can thank Chris Sells for finally convincing me to give // in and implement it. // - Changed operators << and >> (for MFC CArchive) to serialize // EXACTLY as CString's do. So now you can send a CString out // to a CArchive and later read it in as a CStdString. I have // no idea why you would want to do this but you can. // // 1999-JUN-21 - Changed the CStdString class into the CStdStr template. // - Fixed FormatV() to correctly decrement the loop counter. // This was harmless bug but a bug nevertheless. Thanks to // Chris (of Melbsys) for pointing it out // - Changed Format() to try a normal stack-based array before // using to _alloca(). // - Updated the text conversion macros to properly use code // pages and to fit in better in MFC/ATL builds. In other // words, I copied Microsoft's conversion stuff again. // - Added equivalents of CString::GetBuffer, GetBufferSetLength // - new sscpy() replacement of CStdString::CopyString() // - a Trim() function that combines TrimRight() and TrimLeft(). // // 1999-MAR-13 - Corrected the "NotSpace" functional object to use _istpace() // instead of _isspace() Thanks to Dave Plummer for this. // // 1999-FEB-26 - Removed errant line (left over from testing) that #defined // _MFC_VER. Thanks to John C Sipos for noticing this. // // 1999-FEB-03 - Fixed a bug in a rarely-used overload of operator+() that // caused infinite recursion and stack overflow // - Added member functions to simplify the process of // persisting CStdStrings to/from DCOM IStream interfaces // - Added functional objects (e.g. StdStringLessNoCase) that // allow CStdStrings to be used as keys STL map objects with // case-insensitive comparison // - Added array indexing operators (i.e. operator[]). I // originally assumed that these were unnecessary and would be // inherited from basic_string. However, without them, Visual // C++ complains about ambiguous overloads when you try to use // them. Thanks to Julian Selman to pointing this out. // // 1998-FEB-?? - Added overloads of assign() function to completely account // for Q172398 bug. Thanks to "Pete the Plumber" for this // // 1998-FEB-?? - Initial submission // // COPYRIGHT: // 2002 Joseph M. O'Leary. This code is 100% free. Use it anywhere you // want. Rewrite it, restructure it, whatever. If you can write software // that makes money off of it, good for you. I kinda like capitalism. // Please don't blame me if it causes your $30 billion dollar satellite // explode in orbit. If you redistribute it in any form, I'd appreciate it // if you would leave this notice here. // ============
CString的trimleft，trimright和Trim 去除空格
weixin_34293911的博客
02-12 907
Trim只去除首位的空格，如果要去除全部的，用CStringT::Remove方法。 TrimLeft方法的意义是：从字符串左边看起，遇到括号中出现的字符（参数）全部截去，直到出现第一个括号中未出现的字符时停止截除，即使后面又出现了参数中有的字符也不会截去了。TrimLeft方法的意义是：从字符串左边看起，遇到括号中出现的字符（参数）全部截去，直到出现第一个括号中...
CString中TrimLeft（）与TrimRight（）的用法
legend的专栏
06-14 8102
CString::TrimLeft void TrimLeft( ); void CString::TrimLeft( TCHAR chTarget ); void CString::TrimLeft( LPCTSTR lpszTargets ); 参数： chTarget 要被整理的目标字符。 lpszTargets 指向一个字符串的指针，该字符串包含了要被整理的目
CString中 format、trimLeft和trimright、trim 和FindOneOf用法
weixin_30836759的博客
02-22 471
1.format 可以帮助各种类型转换成CString. a. int 转 CString 　　CString str; 　　int number = 4; 　　str.Format(_T("%d"),number); b. double 转 CString 　　CString str; 　　double num = 1.46; 　　str.Format(_T("%lf"),...
CString::TrimLeft
05-30
CString::TrimLeft 是 MFC 中 CString 类的成员函数之一，用于从字符串的左侧开始删除所有空格字符。该函数会改变原字符串，返回值为 void。例如： ``` CString str = " Hello World!"; str.TrimLeft(); // 删除...
请用c++ string实现Cstring的 trim trimleft trimright 带参数的方法
06-06
以下是使用C++ string实现Cstring的trim、trimleft、trimright带参数的方法的示例代码： ```c++ #include #include using namespace std; string trim(string str, const string& chars) { str.erase(0, str....
C++ CString类
05-15
### C++ CString 类详解 #### 引言 `CString` 是 C++ 在 MFC（Microsoft Foundation Classes）框架中提供的一种字符串处理类，它为开发者在处理字符串时提供了丰富的功能和便利性。`CString` 类的强大之处在于其...
CSTRING类的内幕效率研究
12-21
- `void TrimLeft();`：移除字符串左侧的所有空白字符。 - `void TrimRight();`：移除字符串右侧的所有空白字符。 - 这些函数提供了多种字符串格式化和转换的方法，有助于数据清洗和标准化。 7. **其他功能**： ...
CString::trimleft()函数介绍：
lyd_253261362的专栏
08-19 8489
1.     CString   s   =   "0x0001";     s.TrimLeft("0x1");     AfxMessageBox(s);     输出   :   空         2.     CString   s   =   "0x0001";     s.TrimLeft("0x");     AfxMessageBox(s);     输出   :   1    
TrimLeft()和TrimRight()
热门推荐
朵猫猫
03-30 2万+
<br />strming.TrimLeft();  //将字符串最前面的空格修整掉。当在没有参数的情况下调用时，TrimLeft删除换行符，空格和tab字符。 <br /><br />strming.TrimRight()；//消除从右侧起所遇到的所有空格字符
CString中的TrimLeft()和TrimRight()的用法----对比isspace()
Seanyxie Blog
05-27 1万+
一个CString字符串，如果在字符串的开始或结尾有空格的时候，可以使用TrimRight()和TrimLeft()来消去空格，例如CString str="   xiesiyuan    ";CString str1;CString str2; str1=str;str.TrimLeft();str2=str;这时候我们刷新窗口，会发现str1="   xiesi
golang 字节切片 数组 字符串 互转
whatday的专栏
11-19 5490
目录 基本认知 将字符串转为字节切片 将字节切片转为字符串 性能 基本认知 在字符串和字节切片（数组）之间进行转换时，会得到一个全新的切片，其中包含与字符串相同的字节，反之亦然。 转换不会修改数据 唯一的区别是字符串是不可变的，而字节片可以修改 如果需要操纵字符串的 rune ，则可能需要将字符串转换为 rune 切片，更多细节请看这篇文章 Golang 中 runes 和 字符串互转（译文） 将字符串转为字节切片 将字符串转换为字节切片时，会得到一个新的切片，其中包含与字符串相同的
CString字符串查找和截取与去空格(Find，FindOneOf，ReverseFind，Left，Mid，Right,substr，TrimLeft和TrimRight)
lzzw的学习之路
12-26 5526
一、CString之Find（）、FindOneOf()、ReverseFind()。 此三个函数返回值均为整数int。 1、Find() 该函数从最左侧0位置开始索引，查找到第一个出现该字符的位置，返回position。示例如下： CString s("abcabc"); ASSERT( s.Find('b') == 1 ); intf=s.Find("de")...
TrimLeft()和TrimRight()详解
最新发布
微赚淘客开发者博客
01-30 852
在字符串处理中，TrimLeft()和TrimRight()是两个常见的函数，用于移除字符串的左侧（开头）和右侧（结尾）的特定字符或空格。这两个函数有助于规范化字符串的格式，去除不必要的空白或特定字符，提高数据的质量和可读性。通过TrimLeft()和TrimRight()的详细解析，我们更深入地了解了这两个在字符串处理中常用的函数。它们在实际开发中起到了优化字符串格式、提高数据质量的重要作用。
TrimLeft()和TrimRight()详解！
微赚淘客开发者博客
01-12 701
最后，我们将探讨如何实现自定义的Trim函数。通过深度理解，你将能够更加灵活地处理字符串，适应不同的需求。
CString的Trim()方法和TrimStrat()和TrimEnd()方法，TrimRight()和TrimLeft() 方法
zxf347085420的博客
11-02 5678
一、 CString的Trim()方法和TrimStrat()和TrimEnd()方法。这三个方法用于删除字符串头尾出现的某些字符。 Trim()删除字符串头部及尾部出现的空格，删除的过程为从外到内，直到碰到一个非空格的字符为止，所以不管前后有多少个连续的空格都会被删除掉。 TrimStart()只删除字符串的头部的空格。 TrimEnd()只删除字符串尾部的空格。 注意：如果这三个函数...
评论
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付：10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明：

1.余额是钱包充值的虚拟货币，按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载，可以购买VIP、付费专栏及课程。

余额充值