Loop through all controls in view

Question

Hi Everyone,
I need to cycle through all the controls on a view.
I have set each of the controls of type UISegmentedControl with a unique tag number.
I am using this tag number to perform a lookup in database for the value of the segmented control.
So, my question is this.... how do i cycle through all the controls on a view?
thank you
take care
tony

Answer 1

alt-088 wrote:
I think we are close - just one correction.
The segmented controls are all at design time, there will be no new controls added.
I'm not clear on what's been corrected. The sample code I gave you assumed all the controls were known at compile time. So I think the example code addressed the problem you're trying to solve. The last paragraph of that post was just an afterthought, to explain what to do in case you ever needed to add controls dynamically.
-> loop through all controls on view
-> if control is of type uisegmentdcontrol
then do database lookup on tag
Set segment value to value returned from database
Once again, if I correctly understand the above, the code I gave you does exactly what you want. You haven't indicated you want to take any action when a control is not a segmented control, so I don't see why you'd want to include them in the loop. However, if you actually do need to enumerate non-segmented controls (or other subviews), my last response advised you to set the tag properties of all those other controls, making sure the range of those tags is different from the range of the seg control tags.
The part that eludes me is the looping through all the controls on the view
I guess the part that eludes me is why you're so interested in enumerating all the controls, when you only seem to be interested in the segmented controls. But even if you really do need to look at every control, I don't see why you're rejecting the solution I gave you. [viewWithTag:|http://developer.apple.com/iphone/library/documentation/UIKit/Ref erence/UIViewClass/UIView/UIView.html#//appleref/doc/uid/TP40006816-CH3-SW26] is a powerful method which recursively walks the entire view hierarchy to find whatever tag it's looking for. If you use it correctly (e.g. by assigning unique tag numbers that tell you what type of control you've found), it will save you lots of trouble.
If, for some reason, you insist on doing this job without using viewWithTag, the next best might be something like this:
- (void)doSomethingWithEachSegCtrlInView:(UIView *theView) {
UIView *subView;
for (subView in theView.subviews) {
if ([subView respondsToSelector:@selector(selectedSegmentIndex)]) {
// subView is a segmented control ...
else {
// subView is not a segmented control ...
if ([subView.subviews count]) {
// this subview has its own subviews
[self doSomethingWithEachSegCtrlInView:subView];
Note that the above is a more difficult, more error prone method than the sample in my first response. Firstly, it needs to recurse in case any controls are placed on subviews of the main view (or on subviews of those subviews, etc.), a capability already built into viewWithTag. Secondly it needs to identify the type of each subview object. [respondsToSelector:|http://developer.apple.com/iphone/library/documentation/Co coa/Reference/Foundation/Protocols/NSObjectProtocol/Reference/NSObject.html#//appleref/occ/intfm/NSObject/respondsToSelector:] is the preferred way of identifying the class of an object, especially when the selector argument represents one of the methods you intend to use. However there's no reason to get into the business of identifying the class of an object, when you could have given that object a unique tag number in the xib, where there was no question about its class.
Hope the above communicates the solution better than my first response!
- Ray