UIScrollView not working properly with layout constraints - ios

Question

Im trying to place 20Textfields vertically and adding constraints to them programmatically and here is my code for that.
//For creating 20 textfields
-(void)createTextFields
{
//create textfields using for loop
for (int i=0; i<20; i++) {
[self createNew:i+1];
}
}
-(void)createNew:(int )count
{
UITextField *textField=[[UITextField alloc]init];
textField.translatesAutoresizingMaskIntoConstraints=NO;
textField.placeholder=[NSString stringWithFormat:#"Enter text:%u",count];
textField.font=[textField.font fontWithSize:10];
textField.backgroundColor = [UIColor colorWithHue:0.8 saturation:0.1 brightness:0.9 alpha:1];
[containerView addSubview:textField];
[inputFieldsArr addObject:textField];
//Left and width
[containerView addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"|-[textField]-|"
options:0 metrics:nil
views:NSDictionaryOfVariableBindings(textField)]];
//Top and height
[containerView addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"V:|-count-[textField(30)]"
options:0
metrics:#{#"count":[NSNumber numberWithInt:count*50]}
views:NSDictionaryOfVariableBindings(textField)]];
// return textField;
}
//Adding a containerview to scrollview
-(void)createScroll
{
scrollview = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
scrollview.showsVerticalScrollIndicator=YES;
scrollview.scrollEnabled=YES;
scrollview.userInteractionEnabled=YES;
scrollview.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:scrollview];
scrollview.backgroundColor=[UIColor blackColor];
[scrollview setContentSize:CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height)];
UIView *view=self.view;
//Left and width
[self.view addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"|-[scrollview]-|"
options:0 metrics:nil
views:NSDictionaryOfVariableBindings(scrollview)]];
//Top and height
[self.view addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"V:|[scrollview]|"
options:0
metrics:nil
views:NSDictionaryOfVariableBindings(scrollview,view)]];
containerView = [[UIView alloc] init];
containerView.backgroundColor = [UIColor yellowColor]; // just so I can see it
containerView.translatesAutoresizingMaskIntoConstraints = NO;
[scrollview addSubview:containerView];
[self addCOnstriantsToContainer:0];
float height=self.view.frame.size.height;
// CGSize fittingSize = [scrollview systemLayoutSizeFittingSize: UILayoutFittingCompressedSize];
//
// NSLog( #"container fitting size: %#", NSStringFromCGSize( fittingSize ));
//Left and width
}
//Adding Constriants to containerview
-(void)addCOnstriantsToContainer:(float)height
{
float width=self.view.frame.size.width;
// NSLog(#"height:%f",containerView.bounds.size.height);
[scrollview addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"|-[containerView(width)]-|"
options:0
metrics:#{#"width":[NSNumber numberWithFloat:width]}
views:NSDictionaryOfVariableBindings(containerView,scrollview)]];
//Top and height
[scrollview addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:#"V:|-[containerView(==1000)]-|"
options:0
metrics:#{#"height":[NSNumber numberWithFloat:height]}
views:NSDictionaryOfVariableBindings(containerView,scrollview)]];
//constraintsWithVisualFormat:#"V:|-[containerView(1000)]-|"
}
If I use constraintsWithVisualFormat:#"V:|-[containerView(==1000)]-|", it works fine. But I don't want to assign values statically. How can I set them dynamically? I also have tried constraintsWithVisualFormat:#"V:|[containerView(==scrollView)]|". But none of them worked for me.They can't be scrolled beyond the height of the device.
Any ideas to fix this?

Answer 1

Try to add top and height constraints separately for container view, set height same as scrollView's height, and set priority of height constraint to Low Priority.