UITextField的代理方法

• (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
  {
  //iphone鍵盤默認高度216
  CGFloat offset = self.view.frame.size.height - (textField.frame.origin.y + textField.frame.size.height + 216 + 50);
  if (offset <= 0) {
  [UIView animateWithDuration:0.3 animations:^{
  CGRect frame = self.view.frame;
  frame.origin.y = offset;
  self.view.frame = frame;
  }];
  }
  return YES;
  }

• (BOOL)textFieldShouldEndEditing:(UITextField *)textField
  {
  // 輸完后恢復原來的狀態
  [UIView animateWithDuration:0.3 animations:^{
  CGRect frame = self.view.frame;
  frame.origin.y = 0.0;
  self.view.frame = frame;
  }];
  return YES;
  }