IOS7笔记- 7、视图、绘制、手势识别

１、字体设置

#define CORNER_FON_STANDARD_HEIGHT 180.0
-(CGFloat)cornerScaleFator { return self.bounds.size.height / CORNER_FON_STANDARD_HEIGHT;}
UIFont *cornerFont = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
cornerFont = [cornerFont fontWithSize:cornerFont.pointSize * [self cornerScaleFator]];

２、段落设置

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.alignment = NSTextAlignmentCenter;

３、绘图

- (void)drawRect:(CGRect)rect
 {
     // Drawing code
     UIBezierPath *roundedRect = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                                             cornerRadius:[self cornerRadius]];
     [roundedRect addClip];
     
     [[UIColor whiteColor] setFill];
     UIRectFill(self.bounds);
     
     [[UIColor blackColor] setStroke];
     [roundedRect stroke];
     
     if(self.faceUp){
         UIImage *faceImage = [UIImage imageNamed:[NSString stringWithFormat:@"%@%@", [self rankAsString], self.suit]];
         if (faceImage) {
             CGRect imageRect = CGRectInset(self.bounds,
                                            self.bounds.size.width * (1.0 - self.faceCardScaleFactor),
                                            self.bounds.size.height * (1.0 - self.faceCardScaleFactor));
             [faceImage drawInRect:imageRect];
         } else {
             [self drawPips];
         }
         
         [self drawCorners];
     } else {
         [[UIImage imageNamed:@"cardback"] drawInRect:self.bounds];
     }
     
 }

-(void)drawCorners
{
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.alignment = NSTextAlignmentCenter;
    
    UIFont *cornerFont = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
    cornerFont = [cornerFont fontWithSize:cornerFont.pointSize * [self cornerScaleFator]];
    
    NSAttributedString *cornerText = [[NSAttributedString alloc]
                                      initWithString:[NSString stringWithFormat:@"%@
%@", [self rankAsString], self.suit]
                                      attributes:@{NSFontAttributeName : cornerFont, NSParagraphStyleAttributeName :paragraphStyle}];
    CGRect textBounds;
    textBounds.origin = CGPointMake([self cornerOffset], [self cornerOffset]);
    textBounds.size = [cornerText size];
    [cornerText drawInRect:textBounds];
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, self.bounds.size.width, self.bounds.size.height);
    CGContextRotateCTM(context, M_PI);
    [cornerText drawInRect:textBounds];
}

５、添加手势有两种方法：一种是对指定view中拖入手势控件，再由控件Ctrl成相应的Action实现。另一种是先在view相关的Controller中实现公共手势方法，在主View中添加手势事件,如下：

//子View中实现公共手势方法（缩放手势）
-(void)pinch:(UIPinchGestureRecognizer *)gesture
{
    if((gesture.state == UIGestureRecognizerStateChanged ||
        gesture.state == UIGestureRecognizerStateEnded)) {
        self.faceCardScaleFactor *= gesture.scale;
        gesture.scale = 1.0;
    }
}
//主View中添加手势事件
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self.playingCardView addGestureRecognizer:[[UIPinchGestureRecognizer alloc] initWithTarget:self.playingCardView action:@selector(pinch:)]];
}