CGRectMake不起作用

Question

I'm working on example from "iOS Programming Cookbook", based on iOS 7. I need to create UITextField and add it to ViewController .

In ViewController.m I have:

- (void) viewDidLoad {
    [super viewDidLoad];
    [self createField];  
}

- (void) createField {
    self.textField = [[UITextField alloc] initWithFrame:CGRectMake(20.0f, 35.0f, 280.0f, 30.0f)];
    self.textField.translatesAutoresizingMaskIntoConstraints = NO;
    self.textField.borderStyle = UITextBorderStyleRoundedRect;
    self.textField.placeholder = @"Enter text to share";
    self.textField.delegate = self;
    [self.view addSubview:self.textField];
}

On screenshot from book textField appears in the middle of screen's width under the status bar, but when I run it textField appears on the top left corner of screen behind the status bar.

Maybe the problem is, that I run app on iPhone 6 simulator with iOS 8. But I don't know how to solve it.

Thanks!

Answer 1

Using self.textField.translatesAutoresizingMaskIntoConstraints = NO; is pretty much telling the object that it doesn't really care about the frame but relies more on the constraints that you give it. Setting it to YES takes the frame and automatically applies constraints to it to mimic the frame that you give it.

For example it would apply the constraints to have the frame appear at: CGRectMake(20.0f, 35.0f, 280.0f, 30.0f) . When setting it to NO use NSLayoutConstraint and create the constraints programatically.

But in your case just remove the line

self.textField.translatesAutoresizingMaskIntoConstraints = NO;

because it is set to YES by default.