Programming .NET Windows Applications

ProgressBar

A ProgressBar control visually indicates the progress of a time-consuming operation, especially one that does not provide any other indication that the machine is still processing. It might be used for file copy operations, attempts to make a network or internet connection, or a lengthy computation.

The ProgressBar class has just four commonly used properties that are not inherited from Control or some other base class, listed in Table 13-20.

Table 13-20. ProgressBar properties

Property	Value type	Description
Maximum	Integer	Read/write. The maximum value of the range displayed by the control. Default value is 100.
Minimum	Integer	Read/write. The minimum value of the range displayed by the control. Default value is 0.
Step	Integer	Read/write. The amount by which the progress bar is incremented when the PerformStep method is called. Default value is 10.
Value	Integer	Read/write. The current position of the progress bar. Default value is zero.

In addition to the properties listed in Table 13-20, two methods are commonly invoked. The Increment method takes an integer as an argument, incrementing the progress by that amount. The PerformStep method takes no arguments, but increments the progress bar by the amount specified by the Step property.

The programs listed in Example 13-15 (in C#) and Example 13-16 (in VB.NET) demonstrate a progress bar. In these examples, a button click triggers a counter to count up to 10,000. For every 100 counts, a label displays the ...