When you’re debugging a program with many local variables, you usually don’t want to watch all of them; you only need to keep track of a few. You can track specific variables and objects in the Watch window . You can have up to four Watch windows at a time. Watch windows are like by-invitation versions of the Locals window; they list the objects you ask the debugger to keep an eye on, and you can see their values change as you step through the program, as illustrated in Figure 9-12.
The Watch windows are usually tabbed with the Locals window. You can create more than one Watch window to organize the variables you keep an eye on, by selecting Watch 1 through Watch 4 from the Debug menu. You can add a watch by right-clicking on a variable and choosing Add Watch, or just drag the variable to the Watch window. The variable will be added to your Watch window. To remove a variable that you’ve added to your Watch window, right click on it in the Watch list, and select Delete.
If you just need to peek at a variable, and perhaps to experiment with manipulating its value, you can right-click on it and choose QuickWatch , which opens a dialog box with watch information about a single object, as shown in Figure 9-13.
You can enter any expression into the Expression field and
evaluate it from within the QuickWatch window. For example, suppose you
had integer variables named varOne
and varTwo
:
int varOne = 5; int varTwo = 7;
If you want to know the impact of multiplying them, enter:
varOne * varTwo
into the Expression window and click Recalculate. The value is shown in the Value window, as in Figure 9-14.
If you decide that you want to add the variable to a Watch window after all, click the Add Watch button.