iOSsnowanimation

//
// CTSnowAnimationView.h
// CTMyCtrip
//
// Created by alex on 16/1/4.
// Copyright © 2016年 ctrip. All rights reserved.
//

#import
@interface CTSnowAnimationView : UIView
-(id)initWithFrame:(CGRect)frame;
-(void)startSnowWithFlakesNumber:(int)num duration:(float)duration;
-(void)stopSnowAnimation;
-(void)removeSnowAnimation;
@end

//
// CTSnowAnimationView.m
// CTMyCtrip
//
// Created by alex on 16/1/4.
// Copyright © 2016年 ctrip. All rights reserved.
//

#import "CTSnowAnimationView.h"
#define REPEATSNOW @"geneRepeatSnow"
@interface CTSnowAnimationView()
@property (strong, nonatomic) NSMutableArray *snowFlakes;
@end
@implementation CTSnowAnimationView
-(id)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
return self;
}
return [[CTSnowAnimationView alloc] init];
}
-(void)removeSnowAnimation{
for (UIView *flake in self.snowFlakes) {
[flake removeFromSuperview];
}
[[NSNotificationCenter defaultCenter] removeObserver:self name:REPEATSNOW object:nil];
self.snowFlakes = nil;
}
-(void)startSnowWithFlakesNumber:(int)num duration:(float)duration{
dispatch_async(dispatch_get_main_queue(), ^{
if ([self.snowFlakes count] != num) {
if ([self.snowFlakes count] != 0) {
for (UIView *subview in self.snowFlakes) {
[subview removeFromSuperview];
}
}
self.snowFlakes = [NSMutableArray array];
for (int i = 0; i ) {
UIImageView *tmpView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"myctrip_snowflake.png"]];
tmpView.frame = CGRectZero;
tmpView.userInteractionEnabled = FALSE;
[self addSubview:tmpView];
[self.snowFlakes addObject:tmpView];
}
}
[self showFlakes:YES];

[[NSNotificationCenter defaultCenter] removeObserver:self name:REPEATSNOW object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveRepeatNotification:) name:REPEATSNOW object:nil];
for (UIView *flake in self.snowFlakes) {
[flake.layer removeAllAnimations];
}
for (int i = 0; i <[self.snowFlakes count]; i++) {
[self singleFlakeSnow:i withDuration:duration];
}
});
}
-(void)stopSnowAnimation{
for (UIView *flake in self.snowFlakes) {
[flake.layer removeAllAnimations];
}
[self showFlakes:false];
}
- (float)randomFloatBetween:(float)min and:(float)max {
float diff = max - min;
return (((float) (arc4random() % ((unsigned)RAND_MAX + 1)) / RAND_MAX) * diff) + min;
}
-(void)showFlakes:(BOOL)need{
for (UIImageView *flake in self.snowFlakes) {
flake.hidden = !need;
}
}
-(void)singleFlakeSnow:(int)index withDuration:(float)duration{
UIView *flake = self.snowFlakes[index];
int size = [self randomFloatBetween:8.0 and:14.0];
CGRect flakeFrame = flake.frame;
[flake.layer removeAllAnimations];
flake.layer.opacity = 0.1;
flakeFrame.origin.x = arc4random_uniform(CTScreenWidth);
flakeFrame.origin.y = -size;
flakeFrame.size.width = size;
flakeFrame.size.height = size;
flake.frame = flakeFrame;
float delay = arc4random_uniform(5.0);
[self layoutIfNeeded];
[UIView animateWithDuration:duration delay:delay options:UIViewAnimationOptionCurveEaseInOut animations:^{
flake.frame = CGRectMake(flakeFrame.origin.x + 40 - arc4random_uniform(80), self.bounds.size.height, size, size);
flake.layer.opacity = 1.0;
[self layoutIfNeeded];
} completion:^(BOOL finished) {
if (finished) {
[[NSNotificationCenter defaultCenter] postNotificationName:REPEATSNOW object:nil userInfo:@{@"index":[NSNumber numberWithInt:index],
@"duration":[NSNumber numberWithFloat:duration]
}];
}
}];
}
-(void)receiveRepeatNotification:(NSNotification *)notification{
if ([[notification name] isEqualToString:REPEATSNOW]) {
int index = [((NSNumber*)[notification.userInfo objectForKey:@"index"]) intValue];
float duration = [((NSNumber*)[notification.userInfo objectForKey:@"duration"]) floatValue];
[self singleFlakeSnow:index withDuration:duration];
}
}
@end