我的CString 变量的长度被截短了!

Question

没有问题的呀，
void CTestDlg::OnButton1() 
{
CString str;
str="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
MessageBox(str);
}在我的机器上没有问题，CString可以动态增加的

Answer 1

问题在这儿:
CString szSql = CString("UPDATE PMIS.COM_CG_REAL ")
+ "SET "
        + "FIELD_0 = %d,"
        + "FIELD_1 = %d,"
        + "FIELD_2 = %d,"
        + "FIELD_3 = %d,"
        + "FIELD_4 = %d,"
        + "FIELD_5 = %d,"
        + "FIELD_6 = %d,"
        + "FIELD_7 = %d,"
        + "FIELD_8 = %d,"
        + "FIELD_9 = %d,"
        + "FIELD_10 = %d,"
        + "FIELD_11 = %d,"
        + "FIELD_12 = %d,"
        + "FIELD_13 = %d,"
        + "FIELD_14 = %d,"
        + "FIELD_15 = %d,"
        + "FIELD_16 = %d,"
        + "FIELD_17 = %d,"
        + "FIELD_18 = %d,"
        + "FIELD_19 = %d,"
        + "FIELD_20 = %d,"
        + "FIELD_21 = %d,"
        + "FIELD_22 = %d,"
        + "FIELD_23 = %d,"
        + "FIELD_24 = %d,"
        + "FIELD_25 = %d,"
        + "FIELD_26 = %d,"
        + "FIELD_27 = %d,"
.............超过16个加号就不认了,编译器不报错,
但16以后的根本没有加过来,至少在DEBUG窗口看起来是这样的!

Answer 2

没错，我曾碰到过这种情况
DEBUG中看一个字符串确实有长度限制
但程序中没有影响
不信，你放到MessageBox里看

Answer 3

CString 有长度限制， 不信你读个文件试试，读出一个字符串，用MessageBox显示也是一样，只能取到一部分