[Qt-interest] dereferencing a pointer that is invalid

[navid navid]

Hello,

i have encountered crash at

========================================
//header
struct MyControls
{
QComboBox * my_combobox;
QCheckBox * my_checkbox;
};

private:
QList<MyControls *> my_control_list;

//cpp
MyControls mc[8];
mc[0].my_combobox = ui->comboBox1;
...
mc[7].my_combobox = ui->comboBox8;
mc[0].my_checkbox = ui->checkBox1;
...
mc[7].my_checkbox = ui->checkBox8;
my_control_list.clear();
for (int i=0; i<8; i++) {my_control_list.insert(i,&mc[i]);} 

if(ui->checkBox1->isChecked())   return 1;
if (! my_control_list.at(0)->my_checkbox->isChecked())  //<- crash
return 0;

========================================

the crash  error is
myapplication.exe exited with code -1073741819   //(0xC0000005)
It looks like it is dereferencing a pointer that is invalid

//

also as a test
qDebug("list count = %d", my_control_list.count()); //list count = 8
if (! my_control_list.at(0)->my_checkbox->isChecked()) //<- crash

if (! my_control_list.at(1)->my_checkbox->isChecked()) //<- dont crash !

if (! my_control_list.at(2)->my_checkbox->isChecked()) //<- dont crash !

if (! my_control_list.at(7)->my_checkbox->isChecked()) //<- crash

if (! my_control_list.at(8)->my_checkbox->isChecked()) //<- crash 


regards
navid