怎么判断两个cstring变量是否相等？在线等待！！！急！

[alarm_zq]

比如：
CString str1,str2;
如何确定它们是否相等？

[small_wei]

str1.Compare(str2)==0

[ttzzgg_80713]

不是有个Comapre的函数吗？

[ttzzgg_80713]

也可以 == 呀。

[zhangwei2001]

直接用比较符 ==

[alarm_zq]

我是这样用了， 可是就是不行 啊

[memory_xj]

你可以用：
if (!str1.CompareNoCase(str2))
{
//相等
}
else
{
//不相等
}

[programe_ant]

大家好像对CString类还不了解,下面是msdn中的原文:

CString does not have a base class.

A CString object consists of a variable-length sequence of characters. CString provides functions and operators using a syntax similar to that of Basic. Concatenation and comparison operators, together with simplified memory management, make CString objects easier to use than ordinary character arrays.

CString is based on the TCHAR data type. If the symbol _UNICODE is defined for your program, TCHAR is defined as type wchar_t, a 16-bit character type; otherwise, it is defined as char, the normal 8-bit character type. Under Unicode, then, CString objects are composed of 16-bit characters. Without Unicode, they are composed of 8-bit char type.

When not using _UNICODE, CString is enabled for multibyte character sets (MBCS, also known as double-byte character sets, DBCS). Note that for MBCS strings, CString still counts, returns, and manipulates strings based on 8-bit characters, and your application must interpret MBCS lead and trail bytes itself.

CString objects also have the following characteristics:

CString objects can grow as a result of concatenation operations.


CString objects follow “value semantics.” Think of a CString object as an actual string, not as a pointer to a string.


You can freely substitute CString objects for const char* and LPCTSTR function arguments.


A conversion operator gives direct access to the string’s characters as a read-only array of characters (a C-style string).
Tip Where possible, allocate CString objects on the frame rather than on the heap. This saves memory and simplifies parameter passing.

CString assists you in conserving memory space by allowing two strings sharing the same value also to share the same buffer space. However, if you attempt to change the contents of the buffer directly (not using MFC), you can alter both strings unintentionally. CString provides two member functions, CString::LockBuffer and CString::UnlockBuffer, to help you protect your data. When you call LockBuffer, you create a copy of a string, then set the reference count to -1, which "locks" the buffer. While the buffer is locked, no other string can reference the data in that string, and the locked string will not reference another string. By locking the string in the buffer, you ensure that the string’s exclusive hold on the data will remain intact. When you have finished with the data, call UnlockBuffer to reset the reference count to 1.

For more information, see theStrings in MFC andStrings: Unicode and Multibyte Character Set (MBCS) Support articles in Visual C++ Programmer’s Guide andString Manipulation Routines in the Run-Time Library Reference.

#include <afx.h>

那是mfc中设计好的一个类,不同于char字符串!

[happygirllei]

hehe，可以尝试一下用最原始（不过也是最保险最具通用性）的方法：

int len1=str1.length;
int len2=str2.length;
if(len1!=len2)
{
//肯定不相等
}
else
{
int i=1;
while(str1.substring(0,i)==str2.substring(0,i))&&(i<=len1)
{
i=i+1;
}
if(i==len1)
{
//相等
}
else
{
//不等
}

[yg88]

为什么说用==不行？把代码贴出来看看。

[devez]

在msdn上有,查一下就知道了.
有空好好看看msdn.
CString Comparison Operators
BOOL operator ==( const CString& s1, const CString& s2 );

BOOL operator ==( const CString& s1, LPCTSTR s2 );

BOOL operator ==( LPCTSTR s1, const CString& s2 );

BOOL operator !=( const CString& s1, const CString& s2 );

BOOL operator !=( const CString& s1, LPCTSTR s2 );

BOOL operator !=( LPCTSTR s1, const CString& s2 );

BOOL operator <( const CString& s1, const CString& s2 );

BOOL operator <( const CString& s1, LPCTSTR s2 );

BOOL operator <( LPCTSTR s1, const CString& s2 );

BOOL operator >( const CString& s1, const CString& s2 );

BOOL operator >( const CString& s1, LPCTSTR s2 );

BOOL operator >( LPCTSTR s1, const CString& s2 );

BOOL operator <=( const CString& s1, const CString& s2 );

BOOL operator <=( const CString& s1, LPCTSTR s2 );

BOOL operator <=( LPCTSTR s1, const CString& s2 );

BOOL operator >=( const CString& s1, const CString& s2 );

BOOL operator >=( const CString& s1, LPCTSTR s2 );

BOOL operator >=( LPCTSTR s1, const CString& s2 );

Return Value

Nonzero if the strings meet the comparison condition; otherwise 0.

Parameters

s1, s2

CString objects to compare.

Remarks

These comparison operators compare two strings. The operators are a convenient substitute for the case-sensitive Compare member function.

Example

The following example demonstrates the use of CString Comparison Operators.

// example for CString Comparison Operators
CString s1( "abc" );
CString s2( "abd" );
ASSERT( s1 < s2 ); // Operator is overloaded for both.
ASSERT( "ABC" < s1 ); // CString and char*
ASSERT( s2 > "abe" );

CString::Compare
int Compare( LPCTSTR lpsz ) const;

Return Value

Zero if the strings are identical, < 0 if this CString object is less than lpsz, or > 0 if this CString object is greater than lpsz.

Parameters

lpsz

The other string used for comparison.

Remarks

Compares this CString object with another string using the generic-text function _tcscmp. The generic-text function _tcscmp, which is defined in TCHAR.H, maps to either strcmp, wcscmp, or _mbscmp depending on the character set that is defined at compile time. Each of these functions performs a case-sensitive comparison of the strings, and is not affected by locale. For more information, seestrcmp, wcscmp, _mbscmp in the Run-Time Library Reference.

Example

The following example demonstrates the use of CString::Compare.

// example for CString::Compare
CString s1( "abc" );
CString s2( "abd" );
ASSERT( s1.Compare( s2 ) == -1 ); // Compare with another CString.
ASSERT( s1.Compare( "abe" ) == -1 ); // Compare with LPTSTR string.

还是自己去看看吧!

[dycdyc123]

=======

[Jackstraw]

strcmp(str1,str2);
但是，注意str1,str2相等时，返回值是0，而不是TRUE

[软猫克鲁]

应该可以吧，用==。

[Tomorrow_zhf]

同意 jackstraw_lee(稻草人)

[zzxcom]

lj0425(飞来的忧郁)
字符串操作不能使用这样的，
一定要用strcmp，判断返回的是0还是其他，

[zzxcom]

lj0425(飞来的忧郁)
字符串操作不能使用这样的，
一定要用strcmp，判断返回的是0还是其他，

[mashimaro3600]

ai~~~

[林水福]

Comapre

[happygirllei]

快给分！

[akademecia]

== 可以的