CString and GetLength

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MFC console sample showing how CString::GetLength behaves when the string contains an embedded \0, and how Trim and the copy constructor interact with it. Visual Studio 2008 (vcproj) solution.

Source

StringSample/stdafx.cpp C++

// stdafx.cpp : source file that includes just the standard includes
// StringSample.pch will be the pre-compiled header
// stdafx.obj will contain the pre-compiled type information

#include "stdafx.h"

// TODO: reference any additional headers you need in STDAFX.H
// and not in this file

StringSample/StringSample.cpp C++

// StringSample.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "StringSample.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// The one and only application object

CWinApp theApp;

using namespace std;

int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
    int nRetCode = 0;
    CString sampleString = CString(_T("Sample\0String"), 14);
    int len = sampleString.GetLength();  // len is 14

    CString trimmedString = sampleString.Trim(); // trimmedString = "Sample"
    CString newstring = CString(sampleString); // newString = "Sample"
    len = newstring.GetLength(); // len = 14

    newstring.GetBuffer()

    // initialize MFC and print and error on failure
    if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
    {
        // TODO: change error code to suit your needs
        _tprintf(_T("Fatal Error: MFC initialization failed\n"));
        nRetCode = 1;
    }
    else
    {
        // TODO: code your application's behavior here.
    }

    return nRetCode;
}

StringSample/Resource.h C/C++ header

//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ generated include file.
// Used by StringSample.rc
//

#define IDS_APP_TITLE			103

// Next default values for new objects
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE	101
#define _APS_NEXT_COMMAND_VALUE		40001
#define _APS_NEXT_CONTROL_VALUE		1000
#define _APS_NEXT_SYMED_VALUE		101
#endif
#endif

StringSample/stdafx.h C/C++ header

// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//

#pragma once

#include "targetver.h"

#include <stdio.h>
#include <tchar.h>
#define _ATL_CSTRING_EXPLICIT_CONSTRUCTORS      // some CString constructors will be explicit

#ifndef VC_EXTRALEAN
#define VC_EXTRALEAN            // Exclude rarely-used stuff from Windows headers
#endif

#include <afx.h>
#include <afxwin.h>         // MFC core and standard components
#include <afxext.h>         // MFC extensions
#ifndef _AFX_NO_OLE_SUPPORT
#include <afxdtctl.h>           // MFC support for Internet Explorer 4 Common Controls
#endif
#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h>                     // MFC support for Windows Common Controls
#endif // _AFX_NO_AFXCMN_SUPPORT

#include <iostream>



// TODO: reference additional headers your program requires here

StringSample/StringSample.h C/C++ header

#pragma once

#include "resource.h"

StringSample/targetver.h C/C++ header

#pragma once

// The following macros define the minimum required platform.  The minimum required platform
// is the earliest version of Windows, Internet Explorer etc. that has the necessary features to run
// your application.  The macros work by enabling all features available on platform versions up to and
// including the version specified.

// Modify the following defines if you have to target a platform prior to the ones specified below.
// Refer to MSDN for the latest info on corresponding values for different platforms.
#ifndef WINVER                          // Specifies that the minimum required platform is Windows Vista.
#define WINVER 0x0600           // Change this to the appropriate value to target other versions of Windows.
#endif

#ifndef _WIN32_WINNT            // Specifies that the minimum required platform is Windows Vista.
#define _WIN32_WINNT 0x0600     // Change this to the appropriate value to target other versions of Windows.
#endif

#ifndef _WIN32_WINDOWS          // Specifies that the minimum required platform is Windows 98.
#define _WIN32_WINDOWS 0x0410 // Change this to the appropriate value to target Windows Me or later.
#endif

#ifndef _WIN32_IE                       // Specifies that the minimum required platform is Internet Explorer 7.0.
#define _WIN32_IE 0x0700        // Change this to the appropriate value to target other versions of IE.
#endif

StringSample/StringSample.rc Resource script

//Microsoft Visual C++ generated resource script.
//
#include "resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"
/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
LANGUAGE 9, 1
#pragma code_page(1252)


#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE
BEGIN
    "resource.h\0"
END

2 TEXTINCLUDE
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED

/////////////////////////////////////////////////////////////////////////////
//
// String Table
//

STRINGTABLE
BEGIN
   IDS_APP_TITLE       "StringSample"
END

#endif
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//
#ifndef _AFXDLL
#include "afxres.rc"
#endif

/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

StringSample/StringSample.sln Solution file


Microsoft Visual Studio Solution File, Format Version 10.00
# Visual Studio 2008
Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "StringSample", "StringSample.vcproj", "{AAA006C9-0342-4768-930B-E2406DFB49DA}"
EndProject
Global
	GlobalSection(SolutionConfigurationPlatforms) = preSolution
		Debug|Win32 = Debug|Win32
		Release|Win32 = Release|Win32
	EndGlobalSection
	GlobalSection(ProjectConfigurationPlatforms) = postSolution
		{AAA006C9-0342-4768-930B-E2406DFB49DA}.Debug|Win32.ActiveCfg = Debug|Win32
		{AAA006C9-0342-4768-930B-E2406DFB49DA}.Debug|Win32.Build.0 = Debug|Win32
		{AAA006C9-0342-4768-930B-E2406DFB49DA}.Release|Win32.ActiveCfg = Release|Win32
		{AAA006C9-0342-4768-930B-E2406DFB49DA}.Release|Win32.Build.0 = Release|Win32
	EndGlobalSection
	GlobalSection(SolutionProperties) = preSolution
		HideSolutionNode = FALSE
	EndGlobalSection
EndGlobal

StringSample/StringSample.vcproj Project file

<?xml version="1.0" encoding="Windows-1252"?>
<VisualStudioProject
	ProjectType="Visual C++"
	Version="9.00"
	Name="StringSample"
	ProjectGUID="{AAA006C9-0342-4768-930B-E2406DFB49DA}"
	RootNamespace="StringSample"
	Keyword="Win32Proj"
	TargetFrameworkVersion="196613"
	>
	<Platforms>
		<Platform
			Name="Win32"
		/>
	</Platforms>
	<ToolFiles>
	</ToolFiles>
	<Configurations>
		<Configuration
			Name="Debug|Win32"
			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
			IntermediateDirectory="$(ConfigurationName)"
			ConfigurationType="1"
			UseOfMFC="2"
			CharacterSet="1"
			>
			<Tool
				Name="VCPreBuildEventTool"
			/>
			<Tool
				Name="VCCustomBuildTool"
			/>
			<Tool
				Name="VCXMLDataGeneratorTool"
			/>
			<Tool
				Name="VCWebServiceProxyGeneratorTool"
			/>
			<Tool
				Name="VCMIDLTool"
			/>
			<Tool
				Name="VCCLCompilerTool"
				Optimization="0"
				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE"
				MinimalRebuild="true"
				BasicRuntimeChecks="3"
				RuntimeLibrary="3"
				UsePrecompiledHeader="2"
				WarningLevel="3"
				DebugInformationFormat="4"
			/>
			<Tool
				Name="VCManagedResourceCompilerTool"
			/>
			<Tool
				Name="VCResourceCompilerTool"
			/>
			<Tool
				Name="VCPreLinkEventTool"
			/>
			<Tool
				Name="VCLinkerTool"
				LinkIncremental="2"
				GenerateDebugInformation="true"
				SubSystem="1"
				TargetMachine="1"
			/>
			<Tool
				Name="VCALinkTool"
			/>
			<Tool
				Name="VCManifestTool"
			/>
			<Tool
				Name="VCXDCMakeTool"
			/>
			<Tool
				Name="VCBscMakeTool"
			/>
			<Tool
				Name="VCFxCopTool"
			/>
			<Tool
				Name="VCAppVerifierTool"
			/>
			<Tool
				Name="VCPostBuildEventTool"
			/>
		</Configuration>
		<Configuration
			Name="Release|Win32"
			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
			IntermediateDirectory="$(ConfigurationName)"
			ConfigurationType="1"
			UseOfMFC="2"
			CharacterSet="1"
			WholeProgramOptimization="1"
			>
			<Tool
				Name="VCPreBuildEventTool"
			/>
			<Tool
				Name="VCCustomBuildTool"
			/>
			<Tool
				Name="VCXMLDataGeneratorTool"
			/>
			<Tool
				Name="VCWebServiceProxyGeneratorTool"
			/>
			<Tool
				Name="VCMIDLTool"
			/>
			<Tool
				Name="VCCLCompilerTool"
				Optimization="2"
				EnableIntrinsicFunctions="true"
				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE"
				RuntimeLibrary="2"
				EnableFunctionLevelLinking="true"
				UsePrecompiledHeader="2"
				WarningLevel="3"
				DebugInformationFormat="3"
			/>
			<Tool
				Name="VCManagedResourceCompilerTool"
			/>
			<Tool
				Name="VCResourceCompilerTool"
			/>
			<Tool
				Name="VCPreLinkEventTool"
			/>
			<Tool
				Name="VCLinkerTool"
				LinkIncremental="1"
				GenerateDebugInformation="true"
				SubSystem="1"
				OptimizeReferences="2"
				EnableCOMDATFolding="2"
				TargetMachine="1"
			/>
			<Tool
				Name="VCALinkTool"
			/>
			<Tool
				Name="VCManifestTool"
			/>
			<Tool
				Name="VCXDCMakeTool"
			/>
			<Tool
				Name="VCBscMakeTool"
			/>
			<Tool
				Name="VCFxCopTool"
			/>
			<Tool
				Name="VCAppVerifierTool"
			/>
			<Tool
				Name="VCPostBuildEventTool"
			/>
		</Configuration>
	</Configurations>
	<References>
	</References>
	<Files>
		<Filter
			Name="Source Files"
			Filter="cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx"
			UniqueIdentifier="{4FC737F1-C7A5-4376-A066-2A32D752A2FF}"
			>
			<File
				RelativePath=".\stdafx.cpp"
				>
				<FileConfiguration
					Name="Debug|Win32"
					>
					<Tool
						Name="VCCLCompilerTool"
						UsePrecompiledHeader="1"
					/>
				</FileConfiguration>
				<FileConfiguration
					Name="Release|Win32"
					>
					<Tool
						Name="VCCLCompilerTool"
						UsePrecompiledHeader="1"
					/>
				</FileConfiguration>
			</File>
			<File
				RelativePath=".\StringSample.cpp"
				>
			</File>
		</Filter>
		<Filter
			Name="Header Files"
			Filter="h;hpp;hxx;hm;inl;inc;xsd"
			UniqueIdentifier="{93995380-89BD-4b04-88EB-625FBE52EBFB}"
			>
			<File
				RelativePath=".\Resource.h"
				>
			</File>
			<File
				RelativePath=".\stdafx.h"
				>
			</File>
			<File
				RelativePath=".\StringSample.h"
				>
			</File>
			<File
				RelativePath=".\targetver.h"
				>
			</File>
		</Filter>
		<Filter
			Name="Resource Files"
			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav"
			UniqueIdentifier="{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}"
			>
			<File
				RelativePath=".\StringSample.rc"
				>
			</File>
		</Filter>
		<File
			RelativePath=".\ReadMe.txt"
			>
		</File>
	</Files>
	<Globals>
	</Globals>
</VisualStudioProject>

StringSample/ReadMe.txt Text

========================================================================
    CONSOLE APPLICATION : StringSample Project Overview
========================================================================

AppWizard has created this StringSample application for you.

This file contains a summary of what you will find in each of the files that
make up your StringSample application.


StringSample.vcproj
    This is the main project file for VC++ projects generated using an Application Wizard.
    It contains information about the version of Visual C++ that generated the file, and
    information about the platforms, configurations, and project features selected with the
    Application Wizard.

StringSample.cpp
    This is the main application source file.

/////////////////////////////////////////////////////////////////////////////
AppWizard has created the following resources:

StringSample.rc
    This is a listing of all of the Microsoft Windows resources that the
    program uses.  It includes the icons, bitmaps, and cursors that are stored
    in the RES subdirectory.  This file can be directly edited in Microsoft
    Visual C++.

Resource.h
    This is the standard header file, which defines new resource IDs.
    Microsoft Visual C++ reads and updates this file.

/////////////////////////////////////////////////////////////////////////////
Other standard files:

StdAfx.h, StdAfx.cpp
    These files are used to build a precompiled header (PCH) file
    named StringSample.pch and a precompiled types file named StdAfx.obj.

/////////////////////////////////////////////////////////////////////////////
Other notes:

AppWizard uses "TODO:" comments to indicate parts of the source code you
should add to or customize.

/////////////////////////////////////////////////////////////////////////////