iOS development--Kinky skills Summary of various sexual techniques in the development of &ios (IV.)

Summary of various kinky techniques in iOS development (iv)

One: @autoclosure a block of code alive an expression is automatically encapsulated into a closure

Func logiftrue (predicate: ()-Bool) {  if  predicate () {            print ("True " )       

Call

• Logiftrue ({return 2 > 1}) shorthand: logiftrue{2 > 1}

You can omit {} directly using Logiftrue (2>1) when predicate plus @autoclosure call.





Two:?? Definition of:

• Func?? <T> (Optional:t, @autoclosure defaultvalue: () T?)

Three: Closures:

• ({(), () in
• ｝）

Four: operator overloading:

• Func + (left:vector2d, right:vector2d), vector2d {return vector2d (x:left.x + right.x, Y:left.y + right.y)
• ｝

Five: Error- Operator implementation without matching Operator declaration

Because the operator is not declared

• Infix operator +* {associativity None precedence 160
• ｝

• Infix

• Associativity

• Precedence

VI: NSAutoreleasePool realization

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];     int retVal = uiapplicationmain (argc, argv, nil, nil);    [Pool release];     return RetVal;

Seven: About lazy loading:

• Oc

  1  @property (nonatomic, strong) Nsarray * DataArray;    3  //   override get method   4 -(Nsarray *) DataArray   5  {  6  if  (nil == _dataarray) {  7  _dataarray = [Nsarray array];   "   9  return   _dataarray  10 } 

• Swift

You can do it so easily.

1 // 1. Analysis Nsarray is a closure of the return value, and this is a closed packet without parameters 2     Lazy var Dataarray:nsarray = {3         return  []4    } () 5 6     // 2. It can also be written like this 7     Lazy var Dataarray:nsarray = {8         return  nsarray ()9     }()

But that's how we usually load some data.

1 //3. Loading from the plist file2Lazy var dataarray:array<xwwine> = {3Let Winepath = Nsbundle.mainbundle (). Pathforresource ("wine.plist", Oftype:nil)!4 5Let Winesm =Nsmutablearray (contentsoffile:winepath);6 7var tmparray:array<xwwine>! = []8 9              forTmpwinedictinchwinesm! {Ten  Onevar wine:xwwine = xwwine.winewithdict (tmpwinedict as!nsdictionary) A  - tmparray.append (wine) -             } the  -Print"I run it one time") -  -             returnTmparray +}()

Eight: Set the status bar style

• First step: Add a field to Info.plist: View controller-base status bar set to No

• Step two: Add in a parent class where all interfaces inherit:

1. if (ios8_or_later) {//Determine if it is IOS8
2. [[UIApplication sharedapplication] SetStatusBarStyle:UIStatusBarStyleLightContentanimated:NO];
3. }

Nine: Practical KVC way to modify the properties of the inner placeholer of the text box (Uitextfield) (we'll talk about using a custom Uitextview later)

@" username is in here! " ;  [TextField Setvalue:[uicolor Redcolor] Forkeypath: @" _placeholderlabel.textcolor " ];  [TextField setvalue:[uifont boldsystemfontofsize:+] Forkeypath:@ "_ Placeholderlabel.font"];  

This is the way to use the KVC, isn't it very simple? Oh!

iOS development--Kinky skills Summary of various sexual techniques in the development of &ios (IV.)