如何添加放大镜到自定义控件？

如何添加放大镜到自定义控件？ 控制是UIView的一个孩子。 （这是一个UIWebView – 但本机放大function在某些页面不起作用。）

更新：

也许有可能在UIWebView上强制放大镜的绘制？

Answer 1

1.将以下文件添加到您的项目中：

MagnifierView.h：

// // MagnifierView.h // SimplerMaskTest // #import <UIKit/UIKit.h> @interface MagnifierView : UIView { UIView *viewToMagnify; CGPoint touchPoint; } @property (nonatomic, retain) UIView *viewToMagnify; @property (assign) CGPoint touchPoint; @end 

MagnifierView.m：

 // // MagnifierView.m // SimplerMaskTest // #import "MagnifierView.h" #import <QuartzCore/QuartzCore.h> @implementation MagnifierView @synthesize viewToMagnify; @dynamic touchPoint; - (id)initWithFrame:(CGRect)frame { return [self initWithFrame:frame radius:118]; } - (id)initWithFrame:(CGRect)frame radius:(int)r { int radius = r; if ((self = [super initWithFrame:CGRectMake(0, 0, radius, radius)])) { //Make the layer circular. self.layer.cornerRadius = radius / 2; self.layer.masksToBounds = YES; } return self; } - (void)setTouchPoint:(CGPoint)pt { touchPoint = pt; // whenever touchPoint is set, update the position of the magnifier (to just above what's being magnified) self.center = CGPointMake(pt.x, pt.y-66); } - (CGPoint)getTouchPoint { return touchPoint; } - (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext(); CGRect bounds = self.bounds; CGImageRef mask = [UIImage imageNamed: @"[e-mail]"].CGImage; UIImage *glass = [UIImage imageNamed: @"[e-mail]"]; CGContextSaveGState(context); CGContextClipToMask(context, bounds, mask); CGContextFillRect(context, bounds); CGContextScaleCTM(context, 1.2, 1.2); //draw your subject view here CGContextTranslateCTM(context,1*(self.frame.size.width*0.5),1*(self.frame.size.height*0.5)); //CGContextScaleCTM(context, 1.5, 1.5); CGContextTranslateCTM(context,-1*(touchPoint.x),-1*(touchPoint.y)); [self.viewToMagnify.layer renderInContext:context]; CGContextRestoreGState(context); [glass drawInRect: bounds]; } - (void)dealloc { [viewToMagnify release]; [super dealloc]; } @end 

TouchReader.h：

 // // TouchReader.h // SimplerMaskTest // #import <UIKit/UIKit.h> #import "MagnifierView.h" @interface TouchReader : UIView { NSTimer *touchTimer; MagnifierView *loop; } @property (nonatomic, retain) NSTimer *touchTimer; - (void)addLoop; - (void)handleAction:(id)timerObj; @end 

TouchReader.m：

 // // TouchReader.m // SimplerMaskTest // #import "TouchReader.h" #import "MagnifierView.h" @implementation TouchReader @synthesize touchTimer; - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { self.touchTimer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(addLoop) userInfo:nil repeats:NO]; // just create one loop and re-use it. if (loop == nil) { loop = [[MagnifierView alloc] init]; loop.viewToMagnify = self; } UITouch *touch = [touches anyObject]; loop.touchPoint = [touch locationInView:self]; [loop setNeedsDisplay]; } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [self handleAction:touches]; } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [self.touchTimer invalidate]; self.touchTimer = nil; [loop removeFromSuperview]; } - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event { [self.touchTimer invalidate]; self.touchTimer = nil; [loop removeFromSuperview]; } - (void)addLoop { // add the loop to the superview. if we add it to the view it magnifies, it'll magnify itself! [self.superview addSubview:loop]; // here, we could do some nice animation instead of just adding the subview... } - (void)handleAction:(id)timerObj { NSSet *touches = timerObj; UITouch *touch = [touches anyObject]; loop.touchPoint = [touch locationInView:self]; [loop setNeedsDisplay]; } - (void)dealloc { [loop release]; loop = nil; [super dealloc]; } @end 

根据： http : //coffeeshopped.com/2010/03/a-simpler-magnifying-glass-loupe-view-for-the-iphone

2.添加以下图像：

在代码上使用的图像：

[e-mail]：

[e-mail]：

带有阴影的原始但居中的图像（此时不使用）：

[e-mail]：

[e-mail]：

3.用TouchReaderreplace你的xib文件上的主UIView

放大镜将自动工作，除了自己捕捉触摸事件的控件（例如，UIWebView）。 上面的代码不支持带有阴影的图像。 如果您成功解决了这个问题，请添加新的答案。

更新：

更改以下代码以添加UIWebView支持。 UIView应该保持UIView 。

 @interface TouchReader : UILongPressGestureRecognizer 

并向webView添加一个手势：

 TouchReader* gestureMagnifier = [[[TouchReader alloc] initWithTarget:self action:@selector(handleMagnifier:)] autorelease]; gestureMagnifier.webView = editSource; gestureMagnifier.delegate = self; gestureMagnifier.minimumPressDuration = 0.5; [webView addGestureRecognizer:gestureMagnifier]; 

Answer 2

TouchReader.h：

 //- (void)handleAction:(id)timerObj; -(void) handleGestureAction:(CGPoint)location; 

TouchReader.m：

 -(void)awakeFromNib { UILongPressGestureRecognizer * longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)]; [self addGestureRecognizer:longPressGesture]; } -(void)handleGesture:(UILongPressGestureRecognizer *)longPressGesture { CGPoint location = [longPressGesture locationInView:self]; switch (longPressGesture.state) { case UIGestureRecognizerStateBegan: self.touchTimer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(addLoop) userInfo:nil repeats:NO]; // just create one loop and re-use it. if(loop == nil){ loop = [[MagnifierView alloc] init]; loop.viewToMagnify = self; } loop.touchPoint = location; [loop setNeedsDisplay]; break; case UIGestureRecognizerStateChanged: [self handleGestureAction:location]; break; case UIGestureRecognizerStateEnded: [self.touchTimer invalidate]; self.touchTimer = nil; [loop removeFromSuperview]; loop=nil; break; default: break; } } - (void)addLoop { // add the loop to the superview. if we add it to the view it magnifies, it'll magnify itself! [self.superview addSubview:loop]; } -(void) handleGestureAction:(CGPoint)location { loop.touchPoint = location; [loop setNeedsDisplay]; } 

你不需要touches...方法了。