vc开发数据库应用中的常用数据转换

用VC编写数据库程序不可避免的会遇到_bstr_t 、CString 、CTime这几个类型之间的转换问题，令人头疼。今早上终于算是解决了CString和CTime的类型转换问题。

[b]//CTime--〉CString
[/b] CTime t;
t=CTime::GetCurrentTime();
CString sur;
sur.Format("%s",t.Format("%Y-%m-%d"));
MessageBox(sur);

//long --> CString
long a ;
CString b;
b.format("%ld",a);

//double --->CString
double a;
CString b;
b.format("%f",a);

//CString--〉CTime

CString sur;
sur="2006-08-09";
COleDateTime time1;
time1.ParseDateTime(sur);
SYSTEMTIME systime;
VariantTimeToSystemTime(time1, &systime);
CTime tm(systime);
m_time=tm;
UpdateData(false);

CString和int，float之间的转换。

1。int <->CString

1) int ->CString

int n = 1;

CString str;

str.Format("%d",n);

2) CString->int

CString str = "1";

int n = atoi(str.GetBuffer(0));

2. char* 与CString

1)char*->CString

char sz[128];

CString str;

str.Format("%s",sz);

2) CString -> char*

CString str;

int nLength = str.GetLength();

char* sz = new char[nLength];

sz = str.GetBuffer(0);

3. float<->CString

1）float->CString

float f = 0.0;

CString str;

str.Format("%f",f);

2) CString->float

CString str = "0.0";

float f = atof(str.GetBuffer(0));

Format函数第一个参数是要转的那个数的类型