Lưu ý
Cần có ủy quyền mới truy nhập được vào trang này. Bạn có thể thử đăng nhập hoặc thay đổi thư mục.
Cần có ủy quyền mới truy nhập được vào trang này. Bạn có thể thử thay đổi thư mục.
A message indicating that a data type conversion could not take place uses a numeric code to identify the data type. The following tables translate the numeric codes into their equivalent variant data types (for Visual C++) and Automation data types (for Visual Basic).
| Numeric Code | Variant Data Type | Automation Data Type |
|---|---|---|
| 0x0000 | VT_EMPTY | nothing |
| 0x0002 | VT_I2 | 2-byte signed int |
| 0x0003 | VT_I4 | 4-byte signed int |
| 0x0004 | VT_R4 | 4-byte real |
| 0x0005 | VT_R8 | 8-byte real |
| 0x0006 | VT_CY | currency |
| 0x0007 | VT_DATE | date |
| 0x0008 | VT_BSTR | OLE Automation string |
| 0x0009 | VT_DISPATCH | IDispatch * (currently only for recordset pointer) |
| 0x000b | VT_BOOL | True=-1, False=0 |
| 0x000c | VT_VARIANT | VARIANT * |
| 0x000e | VT_DECIMAL | 16-byte fixed point |
| 0x0011 | VT_UI1 | unsigned char |
| 0x0018 | VT_VOID | C style void |
| 0x001b | VT_SAFEARRAY | (use VT_ARRAY in VARIANT) |
| 0x001d | VT_USERDEFINED | user-defined type |
Arrays of the following types have these codes:
| Numeric Code | Variant Data Type | Automation Data Type |
|---|---|---|
| 0x2000 | VT_EMPTY | nothing |
| 0x2002 | VT_I2 | 2-byte signed int |
| 0x2003 | VT_I4 | 4-byte signed int |
| 0x2004 | VT_R4 | 4-byte real |
| 0x2005 | VT_R8 | 8-byte real |
| 0x2006 | VT_CY | currency |
| 0x2007 | VT_DATE | date |
| 0x2008 | VT_BSTR | OLE Automation string |
| 0x2009 | VT_DISPATCH | IDispatch * (currently only for recordset pointer) |
| 0x200b | VT_BOOL | True=-1, False=0 |
| 0x200c | VT_VARIANT | VARIANT * |
| 0x200e | VT_DECIMAL | 16-byte fixed point |
| 0x2011 | VT_UI1 | unsigned char |
| 0x2018 | VT_VOID | C style void |
| 0x201b | VT_SAFEARRAY | (use VT_ARRAY in VARIANT) |
| 0x201d | VT_USERDEFINED | user-defined type |
The following types are passed by reference:
| Numeric Code | Variant Data Type | Automation Data Type |
|---|---|---|
| 0x4000 | VT_EMPTY | nothing |
| 0x4002 | VT_I2 | 2-byte signed int |
| 0x4003 | VT_I4 | 4-byte signed int |
| 0x4004 | VT_R4 | 4-byte real |
| 0x4005 | VT_R8 | 8-byte real |
| 0x4006 | VT_CY | currency |
| 0x4007 | VT_DATE | date |
| 0x4008 | VT_BSTR | OLE Automation string |
| 0x4009 | VT_DISPATCH | IDispatch * (currently only for recordset pointer) |
| 0x400b | VT_BOOL | True=-1, False=0 |
| 0x400c | VT_VARIANT | VARIANT * |
| 0x400e | VT_DECIMAL | 16-byte fixed point |
| 0x4011 | VT_UI1 | unsigned char |
| 0x4018 | VT_VOID | C style void |
| 0x401b | VT_SAFEARRAY | (use VT_ARRAY in VARIANT) |
| 0x401d | VT_USERDEFINED | user-defined type |
Arrays of the following types are passed by reference:
| Numeric Code | Variant Data Type | Automation Data Type |
|---|---|---|
| 0x6000 | VT_EMPTY | nothing |
| 0x6002 | VT_I2 | 2-byte signed int |
| 0x6003 | VT_I4 | 4-byte signed int |
| 0x6004 | VT_R4 | 4-byte real |
| 0x6005 | VT_R8 | 8-byte real |
| 0x6006 | VT_CY | currency |
| 0x6007 | VT_DATE | date |
| 0x6008 | VT_BSTR | OLE Automation string |
| 0x6009 | VT_DISPATCH | IDispatch * (currently only for recordset pointer) |
| 0x600b | VT_BOOL | True=-1, False=0 |
| 0x600c | VT_VARIANT | VARIANT * |
| 0x600e | VT_DECIMAL | 16-byte fixed point |
| 0x6011 | VT_UI1 | unsigned char |
| 0x6018 | VT_VOID | C style void |
| 0x601b | VT_SAFEARRAY | (use VT_ARRAY in VARIANT) |
| 0x601d | VT_USERDEFINED | user-defined type |