一、item宽度相等
1.1、按钮实现
- 确定所需的一列item的最大个数
static NSInteger const corlmax = 4; - 确定item之间的间距
static CGFloat const margin = 20; - 计算item的宽度
[UIScreen mainScreen].bounds.size.width-(corlmax - 1) * margin) / corlmax - 循环创建按钮,根据按钮将要分布所在的行和所在的列确定x,y
int row=i/corlmax;//所在行
int col=i%corlmax;//所在列
CGFloat x= (itemWH+margin)col;
CGFloat y =(itemWH+margin)row;
按钮的总行数: Rows = (count - 1) / cols + 1
按钮的总宽度:width=总列数一个宽度+(总列数-1)间距
按钮的总高度:height=总行数一个宽度+(总行数-1)间距
#import "ViewController.h"
static NSInteger const corlmax = 4;
static CGFloat const margin = 20;
#define itemWH ([UIScreen mainScreen].bounds.size.width-(corlmax - 1) * margin) / corlmax
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
for (int i = 0; i < 10; i++) {
int row=i/corlmax;//所在行
int col=i%corlmax;//所在列
//创建按钮
UIButton *btn= [UIButton buttonWithType:UIButtonTypeCustom];
btn.backgroundColor=[UIColor redColor];
CGFloat x= (itemWH+margin)*col;
CGFloat y =(itemWH+margin)*row;
btn.frame=CGRectMake(x, y, itemWH, itemWH);
[self.view addSubview:btn];
}
}
1.2、UICollectionview实现
#import "ViewController.h"
static NSInteger const cols = 4;
static CGFloat const margin = 10;
#define itemWH ([UIScreen mainScreen].bounds.size.width - 20-(cols - 1) * margin) / cols
static NSString * const ID = @"cell";
@interface ViewController ()
@property (nonatomic, weak) UICollectionView *collectionView;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
// 设置item尺寸
layout.itemSize = CGSizeMake(itemWH, itemWH);
layout.minimumInteritemSpacing = margin;
layout.minimumLineSpacing = margin;
// 创建UICollectionView
UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, 375, 667) collectionViewLayout:layout];
[self.view addSubview:collectionView];
collectionView.backgroundColor=[UIColor whiteColor];
_collectionView = collectionView;
collectionView.dataSource = self;
collectionView.delegate=self;
collectionView.scrollEnabled = NO;
[collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:ID];
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 20;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
// 从缓存池取
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ID forIndexPath:indexPath];
cell.backgroundColor=[UIColor redColor];
return cell;
}
1.3、补充:根据item的个数动态确定collectionview高度
collectionView高度 = rows * itemWH
1.确定item的个数
NSInteger count = _squareItems.count;
2.获得collectionview的总行数
NSInteger rows = (count - 1) / cols + 1;
// Rows = (count - 1) / cols + 1,collectionview万能公式计算总行数
3.// 设置collectioView高度
self.collectionView.frame=CGRectMake(0, 0, 375, rows*itemWH);
二、item宽度不相等
2.1、标签实现
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
CGFloat linemargin = 15;
CGFloat itemmargin = 10;
CGFloat y = 50;
NSArray *arr = @[@"测试",@"测试测试",@"ceshiceshiceshi",@"cccc",@"dddffkkkkf",@"2344",@"rrrrr",@"ffffffffffff",@"0000",@"lopp[[[eoeoeeoro"];
CGRect lastFrame = CGRectZero;
for (int i=0; i<10; i++) {
UILabel *lable = [[UILabel alloc]init];
lable.text = arr[i];
lable.font = [UIFont systemFontOfSize:18];
CGFloat width = [self getWidthWithText:arr[i] height:40 font:18];
lable.backgroundColor = [UIColor redColor];
[self.view addSubview:lable];
if (i==0) {
lable.text = arr[i];
lable.frame = CGRectMake(0, y, width, 40);
}else{
CGFloat x = CGRectGetMaxX(lastFrame) + itemmargin;
if (x+width>[UIScreen mainScreen].bounds.size.width) {
x = 0;
y = CGRectGetMaxY(lastFrame)+linemargin;
}
lable.frame = CGRectMake(x, y, width, 40);
}
lastFrame = lable.frame;
}
}
//根据高度度求宽度 text 计算的内容 Height 计算的高度 font字体大小
-(CGFloat)getWidthWithText:(NSString *)text height:(CGFloat)height font:(CGFloat)font{
CGRect rect = [text boundingRectWithSize:CGSizeMake(MAXFLOAT, height)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:font]}
context:nil];
return rect.size.width;
}
2.2、collectionFlowout布局
flowout.estimatedItemSize = CGSizeMake(40, 40);
flowout.itemSize = UICollectionViewFlowLayoutAutomaticSize;
flowout.minimumLineSpacing = 10;
flowout.minimumInteritemSpacing =10;
-(NSArray *)layoutAttributesForElementsInRect:(CGRect)rect{
NSMutableArray *attributes = [[super layoutAttributesForElementsInRect:rect] mutableCopy];
CGFloat y = 0;
for (int i=0; i0) {
UICollectionViewLayoutAttributes *attr = attributes[i];
CGRect frame = attr.frame;
UICollectionViewLayoutAttributes *preattr = attributes[i-1];
CGFloat x = CGRectGetMaxX(preattr.frame)+self.minimumInteritemSpacing;
if (x+attr.frame.size.width>self.collectionView.frame.size.width) {
x = 0;
y = CGRectGetMaxY(preattr.frame) + self.minimumLineSpacing;
}
frame.origin.x = x;
frame.origin.y = y;
attr.frame = frame;
}
}
return attributes;
}
完整代码链接: https://github.com/15216838624/collectionView.git