1.遍历
在 for-in 遍历存放字典的数组时，出现如下错误，
错误信息
编译失败的原因是 dictionary不知道是哪种类型的，需强制转换成NSDictionary类型。
错误信息
编译成功
2.定义全局变量
var obj = class() //初始化obj，相当于class.init(),分配内存
var obj : class? =nil //初始化obj,为空。
3.对象类型的判断
在oc中，可以使用-isKindOfClass方法判断。
在swift中，用 -is 判断：if obj is class {}
4.重写init方法是，必须增加下面的方法
requiredinit?(coder aDecoder:NSCoder) {
super.init(coder: aDecoder)
fatalError("init(coder:) has not been implemented")
}
5.C语言指针导入到Swift中
1）UnsafePointerUnsafeMutablePointer
声明为常量的指针被导入为UnsafePointer，非常量的指针则被导入为UnsafeMutablePoinger。
比如：
C:
void myFunction(const int *myConstIntPointer);
Swift:
func myFunction(myConstIntPointer: UnsafePointer)
C:
void iTakeAVoidPointer(void *aVoidPointer);
Swift:
func iTakeAVoidPointer(aVoidPointer: UnsafeMutablePointer)
更多详见：http://www.cocoachina.com/swift/20141014/9900.html
6.String 转float、int
funcStringToFloat(str:String)->(CGFloat)
{
letstring = str
varcgFloat:CGFloat=0
ifletdoubleValue =Double(string)
{
cgFloat =CGFloat(doubleValue)
}
returncgFloat
}
funcstringToInt(str:String)->(Int)
{
letstring = str
varint:Int?
ifletdoubleValue =Int(string)
{
int =Int(doubleValue)
}
ifint ==nil
{
return0
}
returnint!
}
7. 添加通知(NotificationCenter)
let notification = NotificationCenter.default
let name = NSNotification.Name.init("")
notification.addObserver(self, selector: #selector(), name:name, object: nil)
8. for 循环倒叙
for i in (0...10).reversed() {
print(i)
}
输出就是 10，9，8...........
9 oc block 与 swift 闭包
http://www.open-open.com/lib/view/open1474524707276.html
10 拍照保存到本地
//选择照片、拍照后回调
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])
{
picker.dismiss(animated: true, completion: nil)
if (picker.sourceType == .camera) //拍照模式下
{
UIImageWriteToSavedPhotosAlbum(info["UIImagePickerControllerOriginalImage"] as! UIImage, self, #selector(DrSelectedDrugInformationViewController.image(image:didFinishSavingWithError:contextInfo:)), nil)
}
}
//保存图片
func image(image: UIImage, didFinishSavingWithError: NSError?, contextInfo: AnyObject)
{
if didFinishSavingWithError != nil {
self.showHint("保存失败")
return
}
}
特别注意的是，在
UIImageWriteToSavedPhotosAlbum(info["UIImagePickerControllerOriginalImage"] as! UIImage, self, #selector(DrSelectedDrugInformationViewController.image(image:didFinishSavingWithError:contextInfo:)), nil)
,#selector()语句中,要调用类名.方法名,否则会cash
10 重写侧滑
//重写侧滑
func handleNavigationTransition()
{
let target = self.navigationController?.interactivePopGestureRecognizer!.delegate
let pan = UIPanGestureRecognizer(target:target,
action:Selector(("handleNavigationTransition:")))
pan.delegate = self
self.view.addGestureRecognizer(pan)
//同时禁用系统原先的侧滑返回功能
self.navigationController?.interactivePopGestureRecognizer!.isEnabled = false
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool
{
if self.childViewControllers.count == 1 //没有push的界面不会触发侧滑
{
return false
}
return true
}
需要UIGestureRecognizerDelegate
