实战项目

添加动画的三种方法

//    [UIView beginAnimations:nil context:nil];

//    [UIView setAnimationDuration:.35];

//    _selectImageView.center = button.center;

//    [UIView commitAnimations];

    

//    [UIView animateWithDuration:.3 animations:^{

//        _selectImageView.center = button.center;

//    }];

//    

    

    [UIView animateWithDuration:.35 animations:^{

        _selectImageView.center = button.center;

        

    } completion:^(BOOL finished) {

        NSLog(@"动画结束");

    }];

UIViewExt

CGPoint CGRectGetCenter(CGRect rect)

{

    CGPoint pt;

    pt.x = CGRectGetMidX(rect);

    pt.y = CGRectGetMidY(rect);

    return pt;

}

CGRect CGRectMoveToCenter(CGRect rect,CGPoint center)

{

    CGRect newrect = CGRectZero;

    newrect.origin.x = center.x-CGRectGetMidX(rect);

    newrect.origin.y = center.y-CGRectGetMidY(rect);

    newrect.size = rect.size;

    return newrect;

}

@implementation UIView (ViewGeometry)

// Retrieve and set the origin

- (CGPoint) origin

{

returnself.frame.origin;

}

- (void) setOrigin: (CGPoint) aPoint

{

CGRect newframe =self.frame;

newframe.origin = aPoint;

self.frame = newframe;

}

// Retrieve and set the size

- (CGSize) size

{

returnself.frame.size;

}

- (void) setSize: (CGSize) aSize

{

CGRect newframe =self.frame;

newframe.size = aSize;

self.frame = newframe;

}

// Query other frame locations

- (CGPoint) bottomRight

{

CGFloat x =self.frame.origin.x +self.frame.size.width;

CGFloat y =self.frame.origin.y +self.frame.size.height;

returnCGPointMake(x, y);

}

- (CGPoint) bottomLeft

{

CGFloat x =self.frame.origin.x;

CGFloat y =self.frame.origin.y +self.frame.size.height;

returnCGPointMake(x, y);

}

- (CGPoint) topRight

{

CGFloat x =self.frame.origin.x +self.frame.size.width;

CGFloat y =self.frame.origin.y;

returnCGPointMake(x, y);

}

// Retrieve and set height, width, top, bottom, left, right

- (CGFloat) height

{

returnself.frame.size.height;

}

- (void) setHeight: (CGFloat) newheight

{

CGRect newframe =self.frame;

newframe.size.height = newheight;

self.frame = newframe;

}

- (CGFloat) width

{

returnself.frame.size.width;

}

- (void) setWidth: (CGFloat) newwidth

{

CGRect newframe =self.frame;

newframe.size.width = newwidth;

self.frame = newframe;

}

- (CGFloat) top

{

returnself.frame.origin.y;

}

- (void) setTop: (CGFloat) newtop

{

CGRect newframe =self.frame;

newframe.origin.y = newtop;

self.frame = newframe;

}

- (CGFloat) left

{

returnself.frame.origin.x;

}

- (void) setLeft: (CGFloat) newleft

{

CGRect newframe =self.frame;

newframe.origin.x = newleft;

self.frame = newframe;

}

- (CGFloat) bottom

{

returnself.frame.origin.y +self.frame.size.height;

}

- (void) setBottom: (CGFloat) newbottom

{

CGRect newframe =self.frame;

newframe.origin.y = newbottom -self.frame.size.height;

self.frame = newframe;

}

- (CGFloat) right

{

returnself.frame.origin.x +self.frame.size.width;

}

- (void) setRight: (CGFloat) newright

{

CGFloat delta = newright - (self.frame.origin.x + self.frame.size.width);

CGRect newframe =self.frame;

newframe.origin.x += delta ;

self.frame = newframe;

}

// Move via offset

- (void) moveBy: (CGPoint) delta

{

CGPoint newcenter =self.center;

newcenter.x += delta.x;

newcenter.y += delta.y;

self.center = newcenter;

}

// Scaling

- (void) scaleBy: (CGFloat) scaleFactor

{

CGRect newframe =self.frame;

newframe.size.width *= scaleFactor;

newframe.size.height *= scaleFactor;

self.frame = newframe;

}

// Ensure that both dimensions fit within the given size by scaling down

- (void) fitInSize: (CGSize) aSize

{

CGFloat scale;

CGRect newframe =self.frame;

if (newframe.size.height && (newframe.size.height > aSize.height))

{

scale = aSize.height / newframe.size.height;

newframe.size.width *= scale;

newframe.size.height *= scale;

}

if (newframe.size.width && (newframe.size.width >= aSize.width))

{

scale = aSize.width / newframe.size.width;

newframe.size.width *= scale;

newframe.size.height *= scale;

}

self.frame = newframe;

}