今天带来的是仿百度外卖首页的重力感应..(由于只能真机测试,手里测试机只有5s,所以有些地方并没有适配其他机型,需要的还需要根据真机自行适配)
来简单说下实现吧,之前重力感应都是用uiaccelerometer实现的,但是,好像是从ios 4 以后,这个方法就废弃了,它被直接封装到了coremotion框架中,所以现在有关重力感应,加速计什么的都需要通过coremotion框架实现,这也算是苹果对于重力感应的整合吧.本文对coremotion框架只是进行了简单的使用,想要更深的使用,还是请自行 google(百度上的文档非常少).
好了.下面就是实现代码
(注意这里需要导入系统框架coremotion.framework)
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//
// viewcontroller.m
// 仿百度外卖首页-重力感应
//
// created by amydom on 16/12/5.
// copyright © 2016年 amydom. all rights reserved.
//
#import "viewcontroller.h"
#import <coremotion/coremotion.h>
@interface viewcontroller ()<uiscrollviewdelegate>{
nstimeinterval updateinterval;
cgfloat setx;//scroll的动态偏移量
}
@property (nonatomic,strong) cmmotionmanager *mmanager;
@property (nonatomic , strong)uiscrollview *myscrollview;
@property (nonatomic , assign)cgfloat offsetx;//初始偏移量
@property (nonatomic , assign)nsinteger offset;
@end
@implementation viewcontroller
- (void)viewdidappear:(bool)animated_{
[super viewdidappear:animated_];
//在界面已经显示后在调用方法(优化)
[self startupdateaccelerometerresult:0];
}
- (void)viewdidload {
[super viewdidload];
self.view.backgroundcolor = [uicolor whitecolor];
[self createview];
}
- (void)createview{
//collectionview
uicollectionviewflowlayout *flowlayout = [[uicollectionviewflowlayout alloc]init];
uicollectionview *mycollection = [[uicollectionview alloc]initwithframe:[uiscreen mainscreen].bounds collectionviewlayout:flowlayout];
mycollection.backgroundcolor = [uicolor whitecolor];
[self.view addsubview:mycollection];
_myscrollview = [[uiscrollview alloc]initwithframe:cgrectmake(0, 22, self.view.frame.size.width, 100)];
_myscrollview.backgroundcolor = [uicolor lightgraycolor];
_myscrollview.delegate = self;
[self.view addsubview:_myscrollview];
for (int i = 0; i < 8; i ++) {
nsstring *name = [nsstring stringwithformat:@"%d.jpg",i + 1];
uiimageview *image = [[uiimageview alloc]initwithframe:cgrectmake(5 + 885 * i, 10, 80, 80)];
image.image = [uiimage imagenamed:name];
image.backgroundcolor = [uicolor orangecolor];
image.layer.maskstobounds = yes;
image.layer.cornerradius = 40;
[_myscrollview addsubview:image];
//偏移量为最后 image 的 frame + origin
_myscrollview.contentsize = cgsizemake (image.frame.size.width + image.frame.origin.x, 10);
}
}
//手指触碰时
- (void)scrollviewwillbegindragging:(uiscrollview *)scrollview{
_offsetx = scrollview.contentoffset.x;
[self stopupdate];
}
- (void)scrollviewdidscroll:(uiscrollview *)scrollview{
//优化处理
setx = scrollview.contentoffset.x;
_offset = scrollview.contentoffset.x - _offsetx;
if (_offset > 0) {
//left
}else{
//right
}
}
//手指离开时
- (void)scrollviewdidenddragging:(uiscrollview *)scrollview willdecelerate:(bool)decelerate{
[self startupdateaccelerometerresult:0];
}
#pragma mark - 重力感应
- (cmmotionmanager *)mmanager
{
if (!_mmanager) {
updateinterval = 1.0/15.0;
_mmanager = [[cmmotionmanager alloc] init];
}
return _mmanager;
}
//开始
- (void)startupdateaccelerometerresult:(void (^)(nsinteger))result
{
if ([self.mmanager isaccelerometeravailable] == yes) {
//回调会一直调用,建议获取到就调用下面的停止方法，需要再重新开始，当然如果需求是实时不间断的话可以等离开页面之后再stop
[self.mmanager setaccelerometerupdateinterval:updateinterval];
[self.mmanager startaccelerometerupdatestoqueue:[nsoperationqueue currentqueue] withhandler:^(cmaccelerometerdata *accelerometerdata, nserror *error)
{
double x = accelerometerdata.acceleration.x;
double y = accelerometerdata.acceleration.y;
if (fabs(y) >= fabs(x))
{//前后
if (y >= 0){
//down
}
else{
//portrait
}
} else { //左右
if (x >= 0){
setx += 10;
if (setx <= 360) {
//由于以10为单位改变 contentoffset, 会出现顿的现象,加上动画就可解决这个问题
[uiview animatewithduration:0.1 animations:^{
_myscrollview.contentoffset = cgpointmake(setx, 0);
}];
//模仿 scroll 的回弹效果
if (setx == 360) {
[uiview animatewithduration:0.5 animations:^{
_myscrollview.contentoffset = cgpointmake(setx + 50, 0);
} completion:^(bool finished) {
[uiview animatewithduration:0.5 animations:^{
_myscrollview.contentoffset = cgpointmake(setx , 0);
}];
}];
}
}else{
setx = 360;
}
}else{
setx -= 10;
if (setx >= 0) {
[uiview animatewithduration:0.1 animations:^{
_myscrollview.contentoffset = cgpointmake(setx, 0);
}];
//模仿 scroll 的回弹效果
if (setx == 0) {
[uiview animatewithduration:0.5 animations:^{
_myscrollview.contentoffset = cgpointmake(setx - 50, 0);
} completion:^(bool finished) {
[uiview animatewithduration:0.5 animations:^{
_myscrollview.contentoffset = cgpointmake(setx, 0);
}];
}];
}
}else{
setx = 0;
}
}
}
}];
}
}
//停止感应方法
- (void)stopupdate
{
if ([self.mmanager isaccelerometeractive] == yes)
{
[self.mmanager stopaccelerometerupdates];
}
}
//离开页面后停止(移除 mmanager)
- (void)dealloc
{
//制空,防止野指针
_mmanager = nil;
}
- (void)didreceivememorywarning {
[super didreceivememorywarning];
// dispose of any resources that can be recreated.
}
@end
到这里,就可以进行真机测试了..
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