本文实例为大家分享了ios实现大雪纷飞动画的具体代码，供大家参考，具体内容如下
1.结果展示
美丽的雪花，勾起了多少美好的回忆。
2.制作思路
其实创作这样一个大学纷飞的场景是十分简单的，简单到你看了教程之后想不会都不行。ok，下面国际惯例，讲解一下思路吧。
1.创建一个数组用来保存大量的雪花
|
1
2
3
4
5
6
7
8
9
|
_imagesarray = [[nsmutablearray alloc] init];
for (int i = 0; i < 1000; ++ i) {
uiimageview *imageview = [[uiimageview alloc] initwithimage:[uiimage imagenamed:@"snow"]];
float x = image_width;
imageview.frame = cgrectmake(image_x, -30, x, x);
imageview.alpha = image_alpha;
[self.view addsubview:imageview];
[_imagesarray addobject:imageview];
}
|
2.使用时钟（cadisplaylink）来控制下雪，为什么不使用nstimer呢。其实是可以的，只是（cadisplaylink）刷帧更快一些。
|
1
2
3
|
//创建时钟，并且添加到主循环中
cadisplaylink *link = [cadisplaylink displaylinkwithtarget:self selector:@selector(makesnow)];
[link addtorunloop:[nsrunloop mainrunloop] formode:nsdefaultrunloopmode];
|
3.下雪，就是把数组当做队列来使用。
每次从数组头部取出一个雪花并且删除其在数组中的占位。
让雪花飘落，通过uiview动画完成frame，transform等改变。
当动画完成之后，将取出的雪花再次放进数组的尾部
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
- (void)makesnow
{
if (_imagesarray.count > 0) {
uiimageview *imageview = _imagesarray[0];
[_imagesarray removeobjectatindex:0];
[self snowfall:imageview];
}
}
- (void)snowfall:(uiimageview *)imageview
{
[uiview animatewithduration:10 animations:^{
imageview.frame = cgrectmake(imageview.frame.origin.x, main_screen_height, imageview.frame.size.width, imageview.frame.size.height);
imageview.transform = cgaffinetransformmakescale(0.3, 0.3);
imageview.transform = cgaffinetransformrotate(imageview.transform, m_pi);
} completion:^(bool finished) {
float x = image_width;
imageview.frame = cgrectmake(image_x, -30, x, x);
[_imagesarray addobject:imageview];
}];
}
|
3.有代码有真相
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
#define image_x arc4random()%(int)main_screen_width
#define image_alpha ((float)(arc4random()%10))/10
#define image_width arc4random()%20 + 10
#define plus_height main_screen_height/25
#define main_screen_height [[uiscreen mainscreen] bounds].size.height
#define main_screen_width [[uiscreen mainscreen] bounds].size.width
#import "viewcontroller.h"
@interface viewcontroller ()
@property (nonatomic ,strong) nsmutablearray *imagesarray;
@property (nonatomic , strong) uiimageview *imageview;
@end
@implementation viewcontroller
- (void)loadview
{
uiimageview *imageview = [[uiimageview alloc]initwithframe:[uiscreen mainscreen].bounds];
imageview.image = [uiimage imagenamed:@"backgound.jpg"];
imageview.contentmode = uiviewcontentmodescaleaspectfill;
self.view = imageview;
}
- (void)viewdidload
{
[super viewdidload];
_imagesarray = [[nsmutablearray alloc] init];
for (int i = 0; i < 1000; ++ i) {
uiimageview *imageview = [[uiimageview alloc] initwithimage:[uiimage imagenamed:@"snow"]];
float x = image_width;
imageview.frame = cgrectmake(image_x, -30, x, x);
imageview.alpha = image_alpha;
[self.view addsubview:imageview];
[_imagesarray addobject:imageview];
}
//创建时钟，并且添加到主循环中
cadisplaylink *link = [cadisplaylink displaylinkwithtarget:self selector:@selector(makesnow)];
[link addtorunloop:[nsrunloop mainrunloop] formode:nsdefaultrunloopmode];
}
- (void)makesnow
{
if (_imagesarray.count > 0) {
uiimageview *imageview = _imagesarray[0];
[_imagesarray removeobjectatindex:0];
[self snowfall:imageview];
}
}
- (void)snowfall:(uiimageview *)imageview
{
[uiview animatewithduration:10 animations:^{
imageview.frame = cgrectmake(imageview.frame.origin.x, main_screen_height, imageview.frame.size.width, imageview.frame.size.height);
imageview.transform = cgaffinetransformmakescale(0.3, 0.3);
imageview.transform = cgaffinetransformrotate(imageview.transform, m_pi);
} completion:^(bool finished) {
float x = image_width;
imageview.frame = cgrectmake(image_x, -30, x, x);
[_imagesarray addobject:imageview];
}];
}
|
4.demo也不能少
下载地址：snow
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/supersonico/article/details/47061771