具有相同變量值的多個自動佈局約束

Question

有沒有辦法從代碼（或直接在界面構建器中）設置多個約束的常量，而無需爲每個約束創建IBOutlet？

Answer 1

你可以使用這樣的事情：

for constraint in view.constraints { 
    // Identify the constraint using a combination of the following: 
    // constraint.identifier == 
    // constraint.firstAttribute == 
    // constraint.firstItem == 
    // constraint.secondAttribute == 
    // constraint.secondItem == 
    // constraint.multiplier == 
    // constraint.constant == 
    if constraint-is-correctly-identified { 
     constraint.constant = 42 
    } 
}