RecordSets are the foundation of database programming. Let’s look at an example that will help you visualize RecordSets and explore the Data control. The Data application, shown in Figure 17.3, is nothing less than a front end for an existing table in a database. VB6 at Work: The Data1 Project To build this application, follow these steps: 1.…
HTML is a great language for displaying information on the client. HTML extensions made Web pages colorful, then interactive. But HTML is a simple language .It wasn’t designed to be a programming language, and no matter how many extensions are introduced, HTML will never become a proper programming language To design interactive Web pages, we need a…
Three of the controls on the Toolbox let you access the computer’s file system. They are the DriveListBox, DirListBox, and FileListBox controls (see Figure 5.19), which are the basic blocks for building dialog boxes that display the host computer’s file system. Using these controls, the user can traverse the host computer’s file system, locate any folders or files on…
Code components are implemented in Visual Basic as Class Modules. Modules have existed in Visual Basic since its first version. They store variable declarations . and code (function subroutines), which are available to all the other components of an application. Many of the examples developed in previous chapters have their own Modules. If the function Convert Temperature(degrees As…
To see the Slider control in use, let’s review a segment of another application, the RTFPad application, which is covered in.Chapter 8, Advanced ActiveX Conirols. The/ Form ‘shown in Figure 5.18 contains a RichTextBox control and two sliders. The RichTextBox control will be explained in Chapter 9. All you need to know about the control to follow the code…
The Colors application demonstrates the difference between the two events. The two Picture Box controls, which display the color designed with the three scroll burs, react differently to the user’s actions. The first Pictureliox is updated from within the Scroll event, which occurs continuously as the user moves the indicator ofjl scroll bar. The second PictureBox is updated from…
The ScroUBar and Slider controls let the user specify a magnitude by scrolling a selector between its minimum and maximum values. In some situations, the user doesn’t know in advance the exact value-of the quantity to specify (in which case, a textbox would suffice), so your application must provide a more flexible mechanism for specifying a value, along with…
The KeyCombo application uses eachcontrol’s ltemData array to store the index of the array element (o r record number, in the case of a random access file) in which the matching record is stored. When a user wants to add a new record, they click the Add New button (see Figure 5.12). When the new record is committed…
The burden of sorting the elements to be searched often lies with the program, but with a flexible tool such as a sorted ListBox control, maintaining’ a.sorted list at all times is ea,sy.Combining a sorted list of keysmaintained by a ListBox control and the Binary Search algorithm is a powerful approach that can be used in situations ‘in which…
Now that we have looked briefly at the technique for maintaining sorted keys in the KeyList application, let’s look at the . code of the project. In the KeyList application (Figure 5.8), to add a new entry, the user must click the Add New button. The program will let the user enter data in the various fields. When…
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