iOS Development-Scratch Awards

or directly on the code, if there is any problem, direct comment.

1. In the YYTScratchView.h file

//

YYTScratchView.h

Demo-Scraping Award

//

Created by Yyt on 16/4/20.

COPYRIGHT©2016 year Yyt. All rights reserved.

//

#import <UIKit/UIKit.h>

@interface Yytscratchview:uiview

@property (nonatomic,assign) float Sizebrush;

-(void) Sethideview: (uiview*) Hideview;

@end

2 in the yytscratchview.m file

//

yytscratchview.m

Demo-Scraping Award

//

Created by Yyt on 16/4/20.

COPYRIGHT©2016 year Yyt. All rights reserved.

//

#import "YYTScratchView.h"

@interface Yytscratchview () {

Cgcontextref _contextmask;//maskcontext User Touch Changes the context

Cgimageref _scratchcgimg;//cgimageref Package _contextmask picture information _contextmask change followed by change until call generation UIImage

Cgpoint Currponit;

Cgpoint Prepoint;

}

@end

@implementation Yytscratchview

-(ID) initWithFrame: (CGRect) frame

{

self = [super Initwithframe:frame];

if (self) {

[Self setopaque:no];

Set transparency if it's opaque, you can't see the next layer.

self.sizebrush=10.0f;

}

return self;

}

-(void) DrawRect: (cgrect) rect

{

[Super Drawrect:rect];

uiimage* Imagetodraw=[uiimage imagewithcgimage:_scratchcgimg];

[imageToDraw DrawInRect:self.frame];

}

Setsizebrush before Sethideview

-(void) Sethideview: (uiview*) hideview{

Cgcolorspaceref Colorspace=cgcolorspacecreatedevicegray ();

CGFloat scale = [UIScreen mainscreen].scale;

Get the cgimage of the current incoming view

Uigraphicsbeginimagecontextwithoptions (hideView.bounds.size, NO, 0);

Hideview.layer.contentsscale=scale;

[Hideview.layer Renderincontext:uigraphicsgetcurrentcontext ()];

Cgimageref Hidecgimg=uigraphicsgetimagefromcurrentimagecontext (). Cgimage;

Uigraphicsendimagecontext ();

Draw the bitmap mask

size_t width=cgimagegetwidth (HIDECGIMG);

size_t height=cgimagegetheight (HIDECGIMG);

Cfmutabledataref pixels;

Pixels=cfdatacreatemutable (NULL, width*height);

Create a mutable dataref for bitmap storage records

_contextmask = Cgbitmapcontextcreate (cfdatagetmutablebyteptr (pixels), width, height, 8, width, colorspace, Kcgimagealphanone);

Data provider

Cgdataproviderref dataprovider=cgdataprovidercreatewithcfdata (pixels);

Fill black background mask Black range for display content white to not display

Cgcontextsetfillcolorwithcolor (_contextmask, [Uicolor Blackcolor]. Cgcolor);

Cgcontextfillrect (_contextmask, self.frame);

Cgcontextsetstrokecolorwithcolor (_contextmask, [Uicolor Whitecolor]. Cgcolor);

Cgcontextsetlinewidth (_contextmask, Self.sizebrush);

Cgcontextsetlinecap (_contextmask, Kcglinecapround);

Cgimageref mask=cgimagemaskcreate (width, height, 8, 8, width, dataprovider, nil, NO);

_scratchcgimg=cgimagecreatewithmask (hidecgimg, mask);

Cgimagerelease (mask);

Cgcolorspacerelease (ColorSpace);

}

-(void) Scratchviewfrom: (cgpoint) startPoint toend: (cgpoint) endpoint{

float Scale=[uiscreen Mainscreen].scale;

CG Y with UI is the y0 of the UI in the top left-hand corner CG in the lower left

Cgcontextmovetopoint (_contextmask, Startpoint.x*scale, (SELF.FRAME.SIZE.HEIGHT-STARTPOINT.Y) *scale);

Cgcontextaddlinetopoint (_contextmask, Endpoint.x*scale, (SELF.FRAME.SIZE.HEIGHT-ENDPOINT.Y) *scale);

Cgcontextstrokepath (_contextmask);

[Self setneedsdisplay];

}

-(void) Touchesbegan: (Nsset *) touches withevent: (uievent *) event{

[Super Touchesbegan:touches Withevent:event];

}

-(void) touchesmoved: (Nsset *) touches withevent: (uievent *) event{

[Super Touchesmoved:touches Withevent:event];

Uitouch *touch=[touches Anyobject];

Currponit=[touch Locationinview:self];

Prepoint=[touch Previouslocationinview:self];

[Self scratchviewfrom:prepoint toend:currponit];

}

-(void) Toucheseend: (Nsset *) touches withevent: (uievent *) event{

[Super Touchesended:touches Withevent:event];

Uitouch *touch=[touches Anyobject];

Currponit=[touch Locationinview:self];

Prepoint=[touch Previouslocationinview:self];

[Self scratchviewfrom:prepoint toend:currponit];

}

-(void) touchescancelled: (Nsset *) touches withevent: (uievent *) event{

[Super Touchescancelled:touches Withevent:event];

}

@end

3. Where calls are required

//

Viewcontroller.m

Demo-Scraping Award

//

Created by Yyt on 16/4/20.

COPYRIGHT©2016 year Yyt. All rights reserved.

//

#import "ViewController.h"

#import "YYTScratchView.h"

@interface Viewcontroller ()

@end

@implementation Viewcontroller

-(void) Viewdidload {

[Super Viewdidload];

Uiimageview *imageview = [[Uiimageview alloc] Initwithframe:cgrectmake (0, 0, Self.view.bounds.size.width, Self.view.bounds.size.height)];

Imageview.image = [UIImage imagenamed:@ "11.png"];

[Self.view Addsubview:imageview];

Uiimageview *imageview2 = [[Uiimageview alloc] Initwithframe:cgrectmake (0, 0, Self.view.bounds.size.width, Self.view.bounds.size.height)];

Imageview2.image = [UIImage imagenamed:@ "22.png"];

[Self.view Addsubview:imageview];

Yytscratchview *scratchview = [[Yytscratchview alloc] Initwithframe:cgrectmake (0, 0, Self.view.bounds.size.width, Self.view.bounds.size.height)];

Scratchview.sizebrush = 20.0;

[Scratchview Sethideview:imageview2];

[Self.view Addsubview:scratchview];

}

@end

iOS Development-Scratch Awards