NSGenericException加入一些限制時programatcially

Question

簡單，這是我的代碼

func showMessageView(){ 
    let leftConstraint = messageView.leftAnchor.constraintEqualToAnchor(self.view.leftAnchor) 
    let bottomConstraint = messageView.bottomAnchor.constraintGreaterThanOrEqualToAnchor(self.view.bottomAnchor) 
    let highConstratin = messageView.heightAnchor.constraintEqualToConstant(44.0) 
    let widthConstraint = messageView.widthAnchor.constraintGreaterThanOrEqualToAnchor(self.view.widthAnchor) 
    NSLayoutConstraint.activateConstraints([leftConstraint, bottomConstraint, highConstratin, widthConstraint]) 
    self.view.translatesAutoresizingMaskIntoConstraints = false 
    self.view.addSubview(messageView) 
} 

和我收到此異常：

終止應用程序由於未捕獲的異常「NSGenericException」，原因：「無法激活約束條目< UIView：0x7fe62e00be70; frame =（0 0; 240 128）; autoresize = RM + BM;層= < CALayer：0x7fe62e06c8f0 >>和< UITableView：0x7fe62c80be00; frame =（0 0; 375 667）; clipsToBounds = YES; autoresize = W + H; gestureRecognizers = < NSArray：0x7fe62b6a54f0>;層= < CALayer：0x7fe62b53aba0>; contentOffset：{0，-64}; contentSize：{375，658}>，因爲它們沒有共同的祖先。約束是否引用不同視圖層次中的項目？這是非法的。「

Answer 1

我解決我的問題只是第一個加入到消息查看這樣的觀點：

func showMessageView(){ 
     self.view.addSubview(messageView) 
     let leftConstraint = messageView.leftAnchor.constraintEqualToAnchor(self.view.leftAnchor) 
     let bottomConstraint = messageView.bottomAnchor.constraintGreaterThanOrEqualToAnchor(self.view.bottomAnchor) 
     let highConstratin = messageView.heightAnchor.constraintEqualToConstant(44.0) 
     let widthConstraint = messageView.widthAnchor.constraintGreaterThanOrEqualToAnchor(self.view.widthAnchor) 
     NSLayoutConstraint.activateConstraints([leftConstraint, bottomConstraint, highConstratin, widthConstraint]) 
     self.view.translatesAutoresizingMaskIntoConstraints = false 
}