首页 > 技术文章 > Class hierarchy of UIResponder as well as subclasses of UIView and UIControl

davidgu 2014-06-24 10:16 原文

 

When you were dragging in your label and your button to this view, you were adding them as subviews.
By doing this programmatically you can see what goes into adding a subview. You’d
need to pass in a frame to the alloc:initWithFrame: method, which is found on
most UIView subclasses:

 

CGRect frame = CGRectMake(0,0,100,20);
UILabel *label = [[UILabel alloc] initWithFrame:frame];

// To add this label to its parent view within a view controller, all you have to
// do is use the addSubView: function.
[self.view addSubView:label];

// Retrieving the frame, making a change to its size or origin, and then 
// resetting its frame property
CGRect frame = label.frame;
frame.origin.x = 10;
frame.size.width = 200;
[label setFrame:frame];

 

 

 

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