xib创建自定义view

1.oc版

+ (instancetype)viewFromXib {
    NSBundle* bundle = [NSBundle mainBundle];
    NSString* className = NSStringFromClass([self class]);
    return [[bundle loadNibNamed:className owner:nil options:nil] objectAtIndexSafe:0];
}

使用：

CustomView* view = [CustomView viewFromXib];

2.swift版

static func newInstance() -> LeftView? {
　　let objc = Bundle.main.loadNibNamed("LeftView", owner: nil, options: nil)
　　if let view = objc?.first as? LeftView {
　　　　return view
　　}
　　return nil
}

使用：

let view = CustomView.newInstance()!