You may notice the variable str Msg underlined in the Visual Studio . It is underlined because the editor recognizes that this variable name has not yet been declared. The Key Up event handler is shown implemented in C# in Example 4-12 and in VB. When the application is run with the implemented Key Up event handler and an uppercase G is again entered in the Text Box, you will get the results shown in Figure 4-9 (scrolling down to the bottom half of the displayed text).
You must declare str Msg as a member variable of the Form1 class so that it is visible to all of the methods of the class. The two Key Down events, for the Shift key and for the G key, are the same as seen previously in Figure 4-8.
Minimum and Maximum character length Validation Here Mudassar Ahmed Khan has explained how to display the ASP. Net Question Answer site, specially started to allow visitors of this site ask their doubts and queries. Just click the Ask Now button and ask your question now.Unicode also allows for character sets containing many more characters than an ASCII character set, such as special symbols and stylings of characters.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.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.Two Labels will simultaneously display the character in both upper- and lowercase, irrespective of how it was entered. During the course of the example, you will also see how to translate keystrokes from one character to another. The Reset button will clear the Text properties of the Text Boxes and Labels. Alternatively, you could use any of the language-specific techniques described earlier in this chapter. e is used just as it was in the actual event handler method, described above.To implement this functionality, add an event handler for the Reset button. In any case, this will bring up a code window with an empty skeleton for the btn Reset_Click event in place and the cursor placed for code entry. Append Text(vb Cr Lf) End Sub Private Sub txt Input_Key Down(By Val sender As Object, _ By Val e As System. The call to the helper method is simple; it involves passing in the name of the event and event argument: Now that you have the Key Down event handler implemented with a helper method to do the work, it is very simple to implement the Key Up event handler in a similar fashion because both events use the same Key Event Args event argument.Add the highlighted lines of code shown in Example 4-6 for C# and in Example 4-7 for VB. Again, remember not to double-click on the txt Input control, since that will implement the default event, which is not what you want here.NET to the event handler skeletons in the code window. Instead, use the techniques described above for the language you are using.The first 128 characters (represented by 7 bits) are standardized and usually referred to as low-order ASCII characters.The upper 128 characters are not standardized, although many well established character sets use all 256 characters. Unicode characters are a superset of the ASCII character set.