循環(huán)創(chuàng)建多個view 是在簡單不過的事 但是多數(shù)時間建立約束時 都是用的init方法 這里記錄一下用Masonry 建立約束的方法
- 先創(chuàng)建裝載的“容器”
_scrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
_scrollView.delegate = self;
_scrollView.pagingEnabled = YES;
_scrollView.showsHorizontalScrollIndicator = NO;
[self.view addSubview:_scrollView];
[_scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
make.centerX.equalTo(self.view.mas_centerX);
make.centerY.equalTo(self.view.mas_centerY).with.offset(-50);
make.width.equalTo(@(200));
make.height.equalTo(@(200));
}];
_scrollView.backgroundColor = [UIColor lightGrayColor];
- 自定義view
需要循環(huán)創(chuàng)建的view 多數(shù)情況下是都是傳入自定義的view
這里 就用這個代替
//此處可以傳view數(shù)組
NSMutableArray * viewARR = [NSMutableArray array];
for (int a = 0; a < 3; a ++) {
UIView * arrview = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 100, 100)];
arrview.backgroundColor = [UIColor whiteColor];
[viewARR addObject:arrview];
}
- 建立約束
左右滾動
UIView * contenview = [UIView new];
[_scrollView addSubview:contenview];
[contenview mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo (_scrollView);
make.height.equalTo (_scrollView); 此處沒有設置寬的約束
}];
//關于這個延遲 因為masory創(chuàng)建約束之后 獲取的frame 是（0，0塌碌，0渊胸，0）但是有一個延遲的話 才能獲取真是的view的大小 延遲時間改成0 也可以
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"******%@",contenview);
});
UIView * lastView ;
//顏色數(shù)組
NSArray * colors = @[ [UIColor purpleColor] , [UIColor orangeColor], [UIColor redColor]];
for (int i = 0; i < viewARR.count ; i++) {
UIView * view = viewARR[i];
[contenview addSubview:view];
[view mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.equalTo (contenview.mas_top);
make.bottom.equalTo (contenview.mas_bottom);
make.left.equalTo(lastView ? lastView.mas_right: @0).offset(10);
make.width.equalTo (_scrollView.mas_width);
}];
view.backgroundColor = colors[i];
lastView = view;
// dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// NSLog(@"=======%d___%@",i,lastView);
// });
}
[contenview mas_updateConstraints:^(MASConstraintMaker *make) {
make.right.equalTo(lastView.mas_right);
}];
上下滾動
UIView * contenview = [UIView new];
[_scrollView addSubview:contenview];
[contenview mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo (_scrollView);
make.width.equalTo (_scrollView);
}];
//關于這個延遲 因為masory創(chuàng)建約束之后 獲取的frame 是（0，0台妆，0翎猛，0）但是有一個延遲的話 才能獲取真是的view的大小 延遲時間改成0 也可以
// dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// NSLog(@"******%@",contenview);
// });
UIView * lastView ;
//顏色數(shù)組
NSArray * colors = @[ [UIColor purpleColor] , [UIColor orangeColor], [UIColor redColor]];
for (int i = 0; i < viewARR.count ; i++) {
UIView * view = viewARR[i];
[contenview addSubview:view];
[view mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo (contenview.mas_left);
make.right.equalTo (contenview.mas_right);
make.top.equalTo(lastView ? lastView.mas_bottom: @0).offset(10);
make.height.equalTo (_scrollView.mas_height);
}];
view.backgroundColor = colors[i];
lastView = view;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"=======%d___%@",i,lastView);
});
}
[contenview mas_updateConstraints:^(MASConstraintMaker *make) {
make.bottom.equalTo(lastView.mas_bottom);
}];
其實就是基于Masonry 和三目運算實現(xiàn) (lastView ? lastView.mas_right: @0).offset(10)
