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iosobjective-cuitextfieldnslayoutconstraint

Adding constraints to UITextField programmatically


I am learning auto layout without using StoryBoard. I have given four constraints of trailing, leading, top and bottom.

Code:

UITextField *searchBarTF=[[UITextField alloc]init];  
[searchBarTF setText:@"is it coming?"];
[views addSubview:searchBarTF];

[views addConstraint:[NSLayoutConstraint constraintWithItem:searchBarTF attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:views attribute:NSLayoutAttributeLeading multiplier:1.0 constant:30]];

[views addConstraint:[NSLayoutConstraint constraintWithItem:searchBarTF attribute:NSLayoutAttributeTrailing   relatedBy:NSLayoutRelationEqual toItem:views attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:30]];

[views addConstraint:[NSLayoutConstraint constraintWithItem:searchBarTF attribute:NSLayoutAttributeTop    relatedBy:NSLayoutRelationEqual toItem:views attribute:NSLayoutAttributeTop multiplier:1.0 constant:30]];

[views addConstraint:[NSLayoutConstraint constraintWithItem:searchBarTF attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:views attribute:NSLayoutAttributeBottom multiplier:1.0 constant:230]];

TextField is not appearing on screen.

Error:

Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want.

Solution

  • You just forget this little piece of code:.

    [searchBarTF setTranslatesAutoresizingMaskIntoConstraints:NO];
    

    By default, this is True. So your constraints are conflicting with Autoresizing constraints.

    The above line will disable auto resizing of your text field and it will apply your defined constraints.