Initializer

init(item:attribute:relatedBy:toItem:attribute:multiplier:constant:)

Creates a constraint that defines the relationship between the specified attributes of the given views.

Declaration

iOS, tvOS
convenience init(item view1: Any, attribute attr1: NSLayoutAttribute, relatedBy relation: NSLayoutRelation, toItem view2: Any?, attribute attr2: NSLayoutAttribute, multiplier: CGFloat, constant c: CGFloat)
macOS
convenience init(item view1: Any, attribute attr1: NSLayoutConstraint.Attribute, relatedBy relation: NSLayoutConstraint.Relation, toItem view2: Any?, attribute attr2: NSLayoutConstraint.Attribute, multiplier: CGFloat, constant c: CGFloat)

Parameters

view1

The view for the left side of the constraint.

attr1

The attribute of the view for the left side of the constraint.

relation

The relationship between the left side of the constraint and the right side of the constraint.

view2

The view for the right side of the constraint.

attr2

The attribute of the view for the right side of the constraint.

multiplier

The constant multiplied with the attribute on the right side of the constraint as part of getting the modified attribute.

c

The constant added to the multiplied attribute value on the right side of the constraint to yield the final modified attribute.

Return Value

A constraint object relating the two provided views with the specified relation, attributes, multiplier, and constant.

Discussion

Constraints represent linear equations of the form view1.attr1 <relation> multiplier × view2.attr2 + c. If the constraint you wish to express does not have a second view and attribute, use nil and notAnAttribute.

See Also

Creating Constraints