Target-Action in iOS Design Pattern

Target-Action in iOS Design Pattern
Target-Action (Target-action) mode (aims to decouple the code, reduce the correlation between the code and the code, and facilitate future development and maintenance) Target-Action-a button used in this design mode, and other controls to turn user interaction into code, so that the program can execute; Target-action: easy to understand, that is, an object contains elements that generate a message expression, when an event is identified, these elements are put together to form a message and send the message. Some concepts are abstract and fuzzy. The Target-Action mode is interpreted using an example below.
First, let's take a look at the following: Release/release/zcrxatv46ubnu7frh1_ldc1by3rpb24oudi8/release = "p1"> + (UIColor *) randomColor.

{

Return [selfcolorWithRed: arc4random () % 256/255 .0 green: arc4random () % 256/255 .0 blue: arc4random () % 256/255 .0 alpha: 1];

}

// Create three UIView objects

Code:

// MHTViewController. m

// LessonTragetAction

// Copyright (c) 2014 Summer. All rights reserved.

# Import "MHTViewController. h"

# Import "CustomView. h"

# Import "UIColor + RandomColor. h"

# Define kCyanView_Frame CGRectMake (100,130,120,120)

# Define kGreenView_Frame CGRectMake (15,260,120,120)

# Define kGrayView_Frame CGRectMake (185,260,120,120)

@ InterfaceMHTViewController ()

@ End

@ Implementation MHTViewController

-(Id) initWithNibName :( NSString *) nibNameOrNil bundle :( NSBundle *) nibBundleOrNil

{

Self = [super initWithNibName: nibNameOrNilbundle: nibBundleOrNil];

If (self ){

// Custom initialization

}

Returnself;

}

-(Void) viewDidLoad

{

[SuperviewDidLoad];

// Do any additional setup after loading the view.

Self. view. backgroundColor = [UIColoryellowColor];

// View1

CustomView * greenView = [[CustomViewalloc] initWithFrame: kGreenView_Frame];

GreenView. backgroundColor = [UIColorgreenColor];

GreenView. layer. cornerRadius = 60;

[GreenViewaddTarget: selfaction: @ selector (changeSuperviewColor :) forControlEvents: UIControlEventTouchUpInside];

GreenView. layer. masksToBounds = YES;

[Self. viewaddSubview: greenView];

[GreenViewrelease];

// View2

CustomView * cyanView = [[CustomViewalloc] initWithFrame: kCyanView_Frame];

CyanView. backgroundColor = [UIColorcyanColor];

[Self. viewaddSubview: cyanView];

CyanView. layer. cornerRadius = 60;

[CyanViewaddTarget: selfaction: @ selector (changeSelfColor :) forControlEvents: UIControlEventTouchDown];

CyanView. layer. masksToBounds = YES;

[CyanViewrelease];

// View3

CustomView * grayView = [[CustomViewalloc] initWithFrame: kGrayView_Frame];

GrayView. backgroundColor = [UIColorgrayColor];

[Self. viewaddSubview: grayView];

[GrayViewaddTarget: selfaction: @ selector (changeSelfLocation :) forControlEvents: UIControlEventTouchUpInside];

GrayView. layer. cornerRadius = 60;

GrayView. layer. masksToBounds = YES;

[GrayViewrelease];

NSArray * titles = @ [@ "change color of parent View", @ "change color", @ "change location"];

For (int I = 0; I <3; I ++ ){

UILabel * lable = [[UILabelalloc] initWithFrame: CGRectMake (120,120,)];

Lable. layer. cornerRadius = 60;

Lable. layer. masksToBounds = YES;

Lable. text = titles [I];

Lable. font = [UIFontfontWithName: @ "EuphemiaUCAS" size: 15];

Lable. textAlignment = NSTextAlignmentCenter;

Lable. backgroundColor = [UIColorclearColor];

If (0 = I ){

[GreenViewaddSubview: lable];

} Elseif (1 = I ){

[CyanViewaddSubview: lable];

} Elseif (2 = I ){

[GrayViewaddSubview: lable];

}

[Lablerelease];

// Set the split line

UILabel * hintLine = [[UILabelalloc] initWithFrame: CGRectMake (50,80, 220,2)];

HintLine. backgroundColor = [UIColorgrayColor];

HintLine. layer. cornerRadius = 5;

HintLine. layer. masksToBounds = YES;

[Self. viewaddSubview: hintLine];

[HintLinerelease];

// Set the prompt content of the Function

UILabel * hintLable = [[UILabelalloc] initWithFrame: CGRectMake (50,60, 220,20)];

HintLable. textAlignment = NSTextAlignmentCenter;

HintLable. text = @ "text display :";

HintLable. font = [UIFontfontWithName: @ "AlNile" size: 12];

[Self. viewaddSubview: hintLable];

[HintLablerelease];

// CopyrightLine (copyright)

UILabel * copyrightLine = [[UILabelalloc] initWithFrame: CGRectMake (20,520,280, 2)];

CopyrightLine. backgroundColor = [UIColorgrayColor];

CopyrightLine. layer. cornerRadius = 5;

CopyrightLine. layer. masksToBounds = YES;

[Self. viewaddSubview: copyrightLine];

[CopyrightLinerelease];

UILabel * copyrightLable = [[UILabelalloc] initWithFrame: CGRectMake (20,480,280, 20)];

CopyrightLable. textAlignment = NSTextAlignmentCenter;

CopyrightLable. text = @ "Copyright? 2014 summer ";

CopyrightLable. font = [UIFontfontWithName: @ "AlNile" size: 12];

[Self. viewaddSubview: copyrightLable];

[CopyrightLablerelease];

UILabel * copyrightLable1 = [[UILabelalloc] initWithFrame: CGRectMake (20,500,280, 20)];

CopyrightLable1.textAlignment = NSTextAlignmentCenter;

CopyrightLable1.text = @ "summer2014mht@sina.com ";

CopyrightLable1.font = [UIFontfontWithName: @ "AlNile" size: 12];

[Self. viewaddSubview: copyrightLable1];

[CopyrightLable1release];

}

// Modify the color of the parent View

-(Void) changeSuperviewColor :( CustomView *) view

{

View. superview. backgroundColor = [UIColorrandomColor];

}

// Modify its own color

-(Void) changeSelfColor :( CustomView *) view

{

View. backgroundColor = [UIColorrandomColor];

}

// Modify its location

-(Void) changeSelfLocation :( CustomView *) view

{

View. center = CGPointMake (arc4random () % (260-60 + 1) + 60, arc4random () % (420-60 + 1) + 60 );

}

Second build Target-Action

// CustomView. h

// LessonTragetAction

// Copyright (c) 2014 Summer. All rights reserved.

# Import

@ Interface CustomView: UIView

// Creation Method

-(Void) addTarget :( id) target action :( SEL) action forControlEvents :( UIControlEvents) controlEvents;

@ End

//*********************

// CustomView. m

// LessonTragetAction

// Copyright (c) 2014 Summer. All rights reserved.

# Import "CustomView. h"

# Import "UIColor + RandomColor. h"

@ InterfaceCustomView ()

{

Id _ target; // target

SEL _ action; // action

UIControlEvents _ controlEvents;

}

@ End

@ Implementation CustomView

-(Id) initWithFrame :( CGRect) frame

{

Self = [super initWithFrame: frame];

If (self ){

// Initialization code

}

Returnself;

}

-(Void) touchesBegan :( NSSet *) touches withEvent :( UIEvent *) event

{

If (UIControlEventTouchDown ==_controlevents ){

// When the current view is exposed to a touch event, it is handled by the target.

[_ Targetpolicmselector: _ actionwithObject: self];

}

}

-(Void) touchesCancelled :( NSSet *) touches withEvent :( UIEvent *) event

{

}

-(Void) touchesEnded :( NSSet *) touches withEvent :( UIEvent *) event

{

If (UIControlEventTouchUpInside = _ controlEvents ){

[_ Targetpolicmselector: _ actionwithObject: self];

}

}

-(Void) touchesMoved :( NSSet *) touches withEvent :( UIEvent *) event

{

}

// Specify for the current view. After the view receives a response event, the target will respond using the action method.

-(Void) addTarget :( id) target action :( SEL) action forControlEvents :( UIControlEvents) controlEvents

{

// Use instance variables to store external input parameters for ease of use in other methods.

_ Target = target;

_ Action = action;

_ ControlEvents = controlEvents; // trigger time

}

@ End