With Java, you can easily write a client program that connects to a Web server and downloads an HTML file. You can also easily expand this simple program into a Web crawler by parsing the downloaded file, extracting the links referenced in that file, and using similar code to download
With Java, it’s easy to write a client program that connects to a TCP/IP server to get the date and time. This is very useful for network testing. Insert your favorite Web server name into the String named server. The program should then display the date and time at the
My code often has a lot of nested procedure calls, which can be painful to trace while doing walk-throughs. Developers might be unaware of the “Procedure Definition” (Shift+F2) feature, which provides a way to go to the code of a called procedure. This is particularly convenient if you like to
This routine parses a string and returns an equivalent string where all the instances of a given substring are doubled. This is especially useful for doubling quotes within SQL statements to be passed to Access or other database engines that expect double quote marks to represent a single quote mark:
To use a picture on a CommandButton, you must set its Picture property and set its Style to 1 – Graphical. Otherwise, the picture will be ignored.
Visual Basic includes constants, such as vbActiveTitleBar and vbButtonFace, for Windows system colors, which the user might change through the Control Panel. (In VB3, these constants are defined in the file CONSTANT.TXT.) When you assign one of these constants to a VB color property, Visual Basic automatically translates it to
Since a class is a namespace, the scope for overloading a member function is confined to the class containing this function. Sometimes, it is necessary to overload the same function in its class as well as in a class derived from it. Using an identical name in a derived class
To change the ToolTips background color, open the Control Panel’s Display tool. Click on the Appearance tab. In the Item combo box, select ToolTip. Click on the little color box to change the color.
In large-scale projects different teams use API functions developed by another team or a third-party vendor. For example: int retrievePerson (int key, Person& recordToBefilled); // original version; used by all teams A problem can arise when the interface of an API is modified by the implementer; all of its users