Null Pointers and Delete
January 3, 2001
C++ guarantees that operator delete checks its argument for null-ness. If the argument is 0, the delete expression has no effect. In other words, deleting a null pointer is a
C++ guarantees that operator delete checks its argument for null-ness. If the argument is 0, the delete expression has no effect. In other words, deleting a null pointer is a
By default, iostream objects are set to display floating point values in fixed notation. To change this, you apply the ‘scientific’ manipulator to an output stream object: #include using namespace
You can determine the line where the caret is in a multiline TextBox control by sending the control a EM_LINEFROMCHAR message, as follows: Private Declare Function SendMessage Lib “user32” Alias
You can’t clear the contents of a MaskEdBox control by setting the Text property to a null string if the MaskEdBox’s Mask property contains delimiter. In fact, you must include
Visual Basic doesn’t let you change the Style property of a CheckBox or an OptionButton control at runtime. However, you can easily do it by manipulating the control’s style bit,
If a form contains one CommandButton control whose Default property is set to True, the Enter key activates the CommandButton. If the form doesn’t contain any default CommandButton control, however,
When you disable a control, VB grays its contents. However, often this action goes unnoticed by the end users. Here’s a routine that changes the control’s BackColor property in addition
At times you may want to temporarily hide the mouse cursor, for example in order to reduce flickering. To do so you just need the ShowCursor API function: Private Declare
An ActiveX DLL doesn’t have direct access to the environment of the calling EXE. For example, the App and Printer objects in the DLL don’t correspond to the objects with