效果: 截图没有显示出抖动效果

//
//  mierLayout.m
//  diaojiba
//
//  Created by point on 16/9/4.
//  Copyright © 2016年 dacai. All rights reserved.
//#import "mierLayout.h"@interface mierLayout()/** 存放所有cell的布局属性 */
@property (nonatomic, strong) NSMutableArray *attrsArray;@property (nonatomic, assign) int row;@property (nonatomic, assign) CGFloat currentX ;@property (nonatomic, assign) CGFloat currentY ;@property (nonatomic, assign) CGFloat preBtnW ;@end@implementation mierLayout- (void)prepareLayout
{[super prepareLayout];_row = 0;_currentX = 0;_currentY = 0;_preBtnW = 0;// 清除之前所有的布局属性[self.attrsArray removeAllObjects];// 开始创建每一个cell对应的布局属性NSInteger count = [self.collectionView numberOfItemsInSection:0];for (NSInteger i = 0; i < count; i++) {// 创建位置NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];// 获取indexPath位置cell对应的布局属性UICollectionViewLayoutAttributes *attrs = [self layoutAttributesForItemAtIndexPath:indexPath];[self.attrsArray addObject:attrs];}}- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{return self.attrsArray;}- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath {UICollectionViewLayoutAttributes *attrs = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];CGFloat mainViewWidth = [UIScreen mainScreen].bounds.size.width;CGFloat w = 50+arc4random() % 100;CGFloat h = 30;CGFloat mw = 10;CGFloat mh = 10;CGFloat x = 0;CGFloat y = 0;static int  i;CGFloat btnWidth = w;if(i == 0 ){_currentX = 0;_preBtnW = btnWidth;}else {if(_preBtnW>mainViewWidth||(_currentX+mw+btnWidth+_preBtnW)>mainViewWidth){_row++;_currentX=0;_preBtnW = btnWidth;}else{_currentX += (mw+_preBtnW);_preBtnW = btnWidth;}}_currentY = _row*(h+mh);attrs.frame = CGRectMake(_currentX, _currentY, w, h);return attrs;
}-(CATransform3D)getTransForm3DWithAngle:(CGFloat)angle{CATransform3D transform =CATransform3DIdentity;//获取一个标准默认的CATransform3D仿射变换矩阵transform=CATransform3DRotate(transform,angle,0,0,1);//获取旋转angle角度后的rotation矩阵。return transform;}- (CGSize)collectionViewContentSize{return CGSizeMake(0, 5000);
}- (NSMutableArray *)attrsArray
{if (!_attrsArray) {_attrsArray = [NSMutableArray array];}return _attrsArray;
}@end