源码下载地址:http://download.youkuaiyun.com/detail/liu537192/8515119
效果图:
核心代码:
//
// JLView.m
// 06-动画
//
// Created by XinYou on 15-3-19.
// Copyright (c) 2015年 vxinyou. All rights reserved.
//
#import "JLView.h"
@interface JLView()
@property (nonatomic, assign)CGFloat snowY;
@end
@implementation JLView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
- (void)awakeFromNib{
// 创建一个定时器,每0.1s刷新一次
[NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(setNeedsDisplay) userInfo:nil repeats:YES];
}
- (void)drawRect:(CGRect)rect
{
self.snowY += 10;
if (self.snowY >= rect.size.height) {
self.snowY = -100;
}
UIImage *image = [UIImage imageNamed:@"snow.jpg"];
[image drawAtPoint:CGPointMake(0, self.snowY)];
}
@end