I use DAO connection ACCESS database, the initialization List Control controls, read ACCESS database data, the MDB tables in the road to make it displayed in a List Control Control, compile no problem, when performing the Debug an Assertion Failed! Error, a vc + + beginners girl, has been for several days still can't solve agghh ah, ask each altar friend for advice! here is the code I wrote:
First in Roadview. CPP, initialize a List Control controls,

 BOOL CRoadview: : OnInitDialog () 
{
CDialog: : OnInitDialog (); 

CFont m_ListFont; 

M_ListFont. CreatePointFont (120, "tahoma"); 

DWORD dwExStyle=m_listroad_view. GetExStyle (); 

DwExStyle&=~ LVS_EX_CHECKBOXES; 

M_listroad_view. SetFont (& amp; M_ListFont); 

M_listroad_view. SetExtendedStyle (dwExStyle | LVS_EX_GRIDLINES | LVS_EX_FULLROWSELECT | LVS_EX_ONECLICKA CTIVATE); 

The TEXTMETRIC tm; 

The CDC * pDC=GetDC (); 

PDC - & gt; GetTextMetrics (& amp; Tm); 

M_listroad_view. InsertColumn (0, "road number", LVCFMT_CENTER, 90, 0). 

M_listroad_view. InsertColumn (1, "road" starting point, LVCFMT_CENTER, 160, 0). 

M_listroad_view. InsertColumn (2, "section radius, LVCFMT_CENTER, 120, 0). 

M_listroad_view. InsertColumn (3, "road length", LVCFMT_CENTER, 120, 0). 

M_listroad_view. InsertColumn (4, "super" route, and LVCFMT_CENTER, 120, 0). 

M_listroad_view. InsertColumn (5, "bending direction", LVCFMT_CENTER, 90, 0). 

M_listroad_view. InsertColumn (6, "grade", LVCFMT_CENTER, 90, 0). 

M_listroad_view. InsertColumn (7, "traffic", LVCFMT_CENTER, 120, 0). 

M_listroad_view. InsertColumn (8, "design", LVCFMT_CENTER, 120, 0). 

//TODO: Add extra initialization here 

return TRUE; 

} 

The results shown in the figure below


My table is as follows:


Then add the read data code is as follows:

 void CMHCSView: : OnRoadView () 
{


COleVariant var.//the field type 

Var. ChangeType (VT_BSTR, NULL); 

CListCtrl m_listroad_view; 

M_listroad_view. DeleteAllItems ();//to empty table 

CDaoDatabase db. 

CDaoRecordset RecSet (& amp; Db); 

The Open (" data. MDB "); 

RecSet. Open (AFX_DAO_USE_DEFAULT_TYPE, "SELECT * FROM road", NULL); 

Cstrings STR [9]. 

int i=0; 
Int j=0; 

while(! RecSet. IsEOF ()) 

{

RecSet. GetFieldValue (" ID ", var); 

STR [0]=var. IntVal; 

RecSet. GetFieldValue (" start ", var); 

STR [1]=(LPCSTR) var. PbstrVal; 

RecSet. GetFieldValue (" radius ", var); 

STR [2]. The Format (" % 10.6 f ", var. DblVal); 

RecSet. GetFieldValue (" length ", var); 

STR [3]. The Format (" % 10.6 f ", var. DblVal); 

RecSet. GetFieldValue (superelevation, var); 

STR [4]. The Format (" % 10.6 f ", var. DblVal); 

RecSet. GetFieldValue (" direction ", var); 

STR [5]=var. IntVal; 

RecSet. GetFieldValue (" grade ", var); 

STR [6]. The Format (" % 10.6 f ", var. DblVal); 

RecSet. GetFieldValue (" volume ", var); 

STR [7]=var. IntVal; 

RecSet. GetFieldValue (" velocity ", var); 

STR [8]. The Format (" % d ", (LPCSTR) var. PbstrVal); 

M_listroad_view. InsertItem (m_listroad_view. GetItemCount (), ""); 

for(j=0; j<=7. J++) 

M_listroad_view. SetItemText (I, j, STR [j]); 

I=I + 1; 

RecSet. MoveNext (); 
} 
RecSet. Close (); 
The Close (); 
CRoadview rv; 
The rv. DoModal (); 

//TODO: Add your command handler code here 

} 

compile right after implementation, the results are as follows:


What's the problem???

CodePudding user response:

Good girl!
Don't see any problems,
You need in OnRoadView ()/OnInitDialog (), respectively, to make a breakpoint, single step, see which place which statements would crash program?

In addition, OnRoadView () defines how m_listroad_view like global variable name? While it is possible, but not norm, easy to misunderstand,
M_ represents the member variables, you this is a local variable.

CodePudding user response:

Breakpoint debugging will not use this one, look not to understand ah,,,

CodePudding user response:

refer to the second floor nowww response:

breakpoint debugging will not use this one, look not to understand ah,,,

Breaking point, F10 step, behold a code will collapse, is targeted to the analysis,

CodePudding user response:

The Debug mode, open the call stack, look at the function call stack, find the error function call ~ first

CodePudding user response:

Direct the compiler to check the call stack, has been back to your code

CodePudding user response:

Collapsed in the pop-up dialog box, press the corresponding button to enter debugging press Alt + 7 key to view the Call Stack, namely "the Call Stack" from the inside to the following out of from the inner to outer function Call history, double-click a row to the cursor to the Call of the source code or assembly instruction, don't understand when double click on the next line, until we can read ,

CodePudding user response:

reference 1st floor l357630798 response:

good girl!
Don't see any problems,
You need in OnRoadView ()/OnInitDialog (), respectively, to make a breakpoint, single step, see which place which statements would crash program?

In addition, OnRoadView () defines how m_listroad_view like global variable name? nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull