UILabel垂直居中內容置頂[轉自stack overflow]

1、    [myLabel sizeToFit];

2、	 myLabel.numberOfLines = 0;
    	[myLabel sizeToFit];

- (void)viewDidLoad

{

[super viewDidLoad];

// 20 point top and left margin. Sized to leave 20 pt at right.

CGRect labelFrame = CGRectMake(20, 20, 280, 150);

UILabel *myLabel = [[UILabel alloc] initWithFrame:labelFrame];

[myLabel setBackgroundColor:[UIColor orangeColor]];

NSString *labelText = @"I am the very model of a modern Major-General, I've information vegetable, animal, and mineral";

[myLabel setText:labelText];

// Tell the label to use an unlimited number of lines

[myLabel setNumberOfLines:0];

[myLabel sizeToFit];

[self.view addSubview:myLabel];

}

// myLabel.textAlignment = NSTextAlignmentRight;

myLabel.textAlignment = NSTextAlignmentCenter;

[myLabel setNumberOfLines:0];

[myLabel sizeToFit];

myLabel.textAlignment = NSTextAlignmentCenter;

[myLabel setNumberOfLines:0];

[myLabel sizeToFit];

CGRect myFrame = myLabel.frame;

// Resize the frame's width to 280 (320 - margins)

// width could also be myOriginalLabelFrame.size.width

myFrame = CGRectMake(myFrame.origin.x, myFrame.origin.y, 280, myFrame.size.height);

myLabel.frame = myFrame;