捏合——缩放

#import "AppDelegate.h"

#import "NewHypnosister.h"

 

@interface AppDelegate ()<UIScrollViewDelegate>

@property (nonatomic, strong) NewHypnosister *hypnosister;

@end

 

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];

    self.window.rootViewController = [[UIViewController alloc]init];

    

    CGRect screenView = self.window.bounds;

    CGRect bigRect = screenView;

    bigRect.size.width *= 2.0;

    bigRect.size.height *= 2.0;

    UIScrollView *scrollView = [[UIScrollView alloc]initWithFrame:screenView];

    //pagingEnabled设置为NO

    [scrollView setPagingEnabled:NO];

    //将NewHypnosister实例变量改为属性

    self.hypnosister = [[NewHypnosister alloc]initWithFrame:screenView];

    //将NewHypnosister对象作为子视图添加到该对象中

    [scrollView addSubview:self.hypnosister];

    

    screenView.origin.x += screenView.size.width;

    NewHypnosister *secondHypnosister = [[NewHypnosister alloc]initWithFrame:screenView];

    [scrollView addSubview:secondHypnosister];

    //属性scrollView的contentSize确定缩放范围

    scrollView.contentSize = self.window.bounds.size;

    //缩放倍数

    scrollView.minimumZoomScale = 1.0;

    scrollView.maximumZoomScale = 5.0;

    //将AppDelegate对象自身设置为scrollView对象的委托

    scrollView.delegate = self;

    

    [self.window makeKeyAndVisible];

    [self.window addSubview:scrollView];

    self.window.backgroundColor = [UIColor whiteColor];

    return YES;

}

 

---

#import "NewHypnosister.h"

 

@interface NewHypnosister()

@property (strong, nonatomic)UIColor *circleColor;

@end

 

@implementation NewHypnosister

 

- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self){

        self.backgroundColor = [UIColor clearColor];

        self.circleColor = [UIColor lightGrayColor];

    }

    return self;

}

- (void)drawRect:(CGRect)rect

{

    CGRect bounds = self.bounds;

    CGPoint center;

    center.x = (bounds.origin.x + bounds.size.width)/2.0;

    center.y = (bounds.origin.y + bounds.size.height)/2.0;

    float maxRadius = hypot(bounds.size.width, bounds.size.height)/2.0;

    

    

    UIBezierPath *path = [[UIBezierPath alloc]init];

    for (float currentRadius = maxRadius; currentRadius > 0; currentRadius -= 20.0) {

        [path moveToPoint:CGPointMake(center.x + currentRadius, center.y)];

        [path addArcWithCenter:center

                        radius:currentRadius

                    startAngle:0.0

                      endAngle:M_PI*2.0

                     clockwise:YES];

    }

    path.lineWidth = 10.0;

//    [[UIColor lightGrayColor] setStroke];

    [self.circleColor setStroke];

    

    [path stroke];

    //设置阴影

    CGContextRef currentContext = UIGraphicsGetCurrentContext();

    void CGContextShadow(CGContextRef context, CGSize offSet, CGFloat blur);

    CGContextSetShadow(currentContext, CGSizeMake(4, 7), 3);

    //绘制三角形，顶点(bounds.origin.x + bounds.size.width/2.0, bounds.origin.y),底边为bounds底边

    UIBezierPath *myPath = [UIBezierPath bezierPath];

    

    CGPoint myPoint[3];

    myPoint[0] = CGPointMake(bounds.origin.x + bounds.size.width/2.0, bounds.origin.y);

    myPoint[1] = CGPointMake(bounds.origin.x, bounds.origin.y + bounds.size.height);

    myPoint[2] = CGPointMake(bounds.origin.x + bounds.size.width, bounds.origin.y + bounds.size.height);

    //绘制三角形

    [myPath moveToPoint:myPoint[0]];

    [myPath addLineToPoint:myPoint[1]];

    [myPath addLineToPoint:myPoint[2]];

    [myPath stroke];

    //保存剪切三角形及设置颜色渐变

    CGContextSaveGState(currentContext);

    [myPath addClip];

    

    CGFloat locations[2] = {0.0, 1.0};

    CGFloat components[8] = {0.0, 1.0, 0.0, 1.0,//起始颜色为黄色

                             1.0, 1.0, 0.0, 1.0};//终止颜色为绿色

    CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();

    CGGradientRef gradient = CGGradientCreateWithColorComponents(colorspace, components, locations, 2);

    

    CGPoint startPoint = myPoint[0];

    CGPoint endPoint = myPoint[2];

    CGContextDrawLinearGradient(currentContext, gradient, startPoint, endPoint, 0);

    CGGradientRelease(gradient);

    CGColorSpaceRelease(colorspace);

    

    CGContextRestoreGState(currentContext);

    

    UIImage *logoImage = [UIImage imageNamed:@"logo.png"];

    [logoImage drawInRect:rect];

    

}

 

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

{

    NSLog (@"%@ was touched", self);

    float red = (arc4random()%100)/100.0;

    float green = (arc4random()%100)/100.0;

    float blue = (arc4random()%100)/100.0;

    

    UIColor *randomColor = [[UIColor alloc]initWithRed:red

                                                 green:green

                                                  blue:blue

                                                 alpha:1.0];

    _circleColor = randomColor;

}

 

- (void)setCircleColor:(UIColor *)circleColor

{

    _circleColor = circleColor;

    [self setNeedsDisplay];

}

 

 

@end