如何在不知道大小的情况下malloc数组结构

Question

我有一个单词结构：

typedef struct {
   char *word;
   unsigned long occurrences;
} Word;

我想要malloc这些数组，但我不知道它的大小有多大。有没有办法在不事先知道数组大小的情况下对malloc结构数组进行malloc？

感谢。

Answer 1

您可以使用viewdidload()分配内存，然后使用var secondaryMenuBottomConstraint: NSLayoutConstraint! func setupSecondaryMenu(secondaryMenu: UIView){ secondaryMenu.translatesAutoresizingMaskIntoConstraints = false let topConstraint = secondaryMenu.topAnchor.constraintEqualToAnchor(view.bottomAnchor) let leftConstraint = secondaryMenu.leftAnchor.constraintEqualToAnchor(view.leftAnchor) let rightConstraint = secondaryMenu.rightAnchor.constraintEqualToAnchor(view.rightAnchor) view.addSubview(secondaryMenu) NSLayoutConstraint.activateConstraints([topConstraint, leftConstraint, rightConstraint]) self.view.layoutIfNeeded() secondaryMenu.removeFromSuperview() } func showSecondaryMenu(secondaryMenu: UIView){ //Close any open keyboards amountTextField.resignFirstResponder() notesTextField.resignFirstResponder() //Add the view and then add constraints to show the submenu below the current view secondaryMenu.translatesAutoresizingMaskIntoConstraints = false let topConstraint = secondaryMenu.topAnchor.constraintEqualToAnchor(view.bottomAnchor) let leftConstraint = secondaryMenu.leftAnchor.constraintEqualToAnchor(view.leftAnchor) let rightConstraint = secondaryMenu.rightAnchor.constraintEqualToAnchor(view.rightAnchor) view.addSubview(secondaryMenu) NSLayoutConstraint.activateConstraints([topConstraint, leftConstraint, rightConstraint]) secondaryMenuBottomConstraint = secondaryMenu.bottomAnchor.constraintEqualToAnchor(view.bottomAnchor) //animate the view up into place UIView.animateWithDuration(0.4, animations: { topConstraint.active = false self.secondaryMenuBottomConstraint.active = true self.view.layoutIfNeeded() }) } func dismissSecondaryMenu(secondaryMenu: UIView){ if secondaryMenu.superview != nil { secondaryMenu.translatesAutoresizingMaskIntoConstraints = false let secondaryMenuTopConstraint = secondaryMenu.topAnchor.constraintEqualToAnchor(view.bottomAnchor) self.secondaryMenuBottomConstraint.active = false UIView.animateWithDuration(0.4, animations: { secondaryMenuTopConstraint.active = true self.view.layoutIfNeeded() }, completion: {(finished:Bool) in secondaryMenu.removeFromSuperview() }) } }

更改大小

malloc()