They are represented by two bytes, which allows a maximum of 65,536 characters.The Unicode technology was introduced to allow easier representation of languages other than English, especially Asian languages such as Chinese and Japanese, which do not have limited alphabets.
You can insert Unicode characters or determine the Unicode character code for any character in Windows using the Character Map tool, which is accessible by clicking on the Start menu and then Programs The Key Press event exposes two properties contained in Key Press Event Args, listed in Table 4-7.In the next example, you will create a simple Windows application with a single-line Text Box for entering keystrokes. Set the properties of the form and the controls to the values shown in Table 4-8. It takes two arguments: a string which should contain the name of the event and the instance of Key Event Args.A larger multiline Text Box will display the keystroke events and event argument properties so that you can see what is going on. When done, the form should look something like Figure 4-7. The first argument is used in the first line in the method to display which event is being handled.The decimal key code value in Appendix A corresponds to the virtual-key codes familiar to Windows programmers.Unicode and ASCII Characters Each character in the American Standards Committee for Information Interchange (ASCII) character set is represented by a single byte (8 bits) of data, representing 256 characters.Now most of the time the user needs validation in a Windows application, so before the user enters a wrong value (such as instead of text the user enters an integer) we can validate it using an event and some sort of coding.