UIButton图片位置
```
// TitleButton.swift
import UIKit
class TitleButton: UIButton {
override init(frame: CGRect) {
super.init(frame: frame)
setTitleColor(UIColor.darkGrayColor(), forState: UIControlState.Normal)
setImage(UIImage(named: "navigationbar_arrow_down"), forState: UIControlState.Normal)
setImage(UIImage(named: "navigationbar_arrow_up"), forState: UIControlState.Highlighted)
sizeToFit()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
/**
这个方法里调整布局
*/
override func layoutSubviews() {
super.layoutSubviews()
titleLabel?.frame.origin.x = 0
imageView?.frame.origin.x = titleLabel!.frame.size.width
}
}
```
