Masonry是一個輕量級的自動布局庫，采用獨特的鏈式語法進行代碼封裝，具有高可用性和閱讀性等特點， 下面來說一下幾個實用的例子！
1. 設(shè)置類似下圖的布局約束
//設(shè)置一組button的約束
- (void)masonryArrayWithButton
{
NSArray *titleArray = @[@"按鈕1", @"按鈕2", @"按鈕3", @"按鈕4"];
NSMutableArray *mArray = [NSMutableArray array];
for (NSInteger i = 0; i < titleArray.count; i++) {
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:titleArray[i] forState:UIControlStateNormal];
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
button.layer.borderColor = [UIColor blackColor].CGColor;
button.layer.borderWidth = 2;
[self.view addSubview:button];
[mArray addObject:button];
}
[mArray mas_distributeViewsAlongAxis:MASAxisTypeHorizontal withFixedSpacing:20 leadSpacing:20 tailSpacing:20];
[mArray mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.equalTo(@100);
make.height.equalTo(@40);
}];
}
2. ?不設(shè)置寬高，會自動適應(yīng)
//不設(shè)置UILabel寬跟高的值
-(void)masonryLabelHeightLayout
{
//文本控件UILabel、按鈕UIButton、圖片視圖UIImageView等，它們具有自身內(nèi)容尺寸（Intrinsic Content Size），此類用戶控件會根據(jù)自身內(nèi)容尺寸添加布局約束。也就是說，如果開發(fā)者沒有顯式給出其寬度或者高度約束，則其自動添加的自身內(nèi)容約束將會起作用。因此看似“缺失”約束，實際上并非如此
UILabel *myLabel=[[UILabel alloc]init];
myLabel.backgroundColor=[UIColor redColor];
myLabel.text=@"A測試Label不設(shè)高度時它的默認值測試Label不設(shè)高度時它的默認值";
myLabel.numberOfLines = 0;
[self.view addSubview:myLabel];
[myLabel mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.mas_equalTo(150);
make.left.mas_equalTo(20);
make.right.mas_equalTo(-60);
}];
UILabel *mySecondLabel=[[UILabel alloc]init];
mySecondLabel.backgroundColor=[UIColor blueColor];
mySecondLabel.text=@"確認";
[self.view addSubview:mySecondLabel];
[mySecondLabel mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.mas_equalTo(myLabel.mas_right).offset(10);
make.centerY.mas_equalTo(myLabel);
}];
}
3. 適用于 一行多個控件 設(shè)定一個為優(yōu)先級問題
//優(yōu)先級 及至少的情況
-(void)masonryPriorityLayout
{
UILabel *myLabel=[[UILabel alloc]init];
myLabel.backgroundColor=[UIColor redColor];
myLabel.text=@"B1測試Label不設(shè)高度時它的默認值,再增加文字長度時的情況";
myLabel.numberOfLines = 0;
[self.view addSubview:myLabel];
[myLabel mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.mas_equalTo(200);
make.left.mas_equalTo(20);
//至少至右邊有80的空間，優(yōu)先級設(shè)高，如果文字不夠長 它會以文字本來的寬度
make.right.mas_lessThanOrEqualTo(-80).with.priorityHigh();
}];
UILabel *mySecondLabel=[[UILabel alloc]init];
mySecondLabel.backgroundColor=[UIColor blueColor];
mySecondLabel.text=@"確認";
[self.view addSubview:mySecondLabel];
[mySecondLabel mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.mas_equalTo(myLabel);
make.left.mas_equalTo(myLabel.mas_right).offset(10);
}];
}
4. ?為滾動視圖添加約束
//滾動視圖添加約束
-(void)masonryScrollViewLayout
{
UIScrollView *scrollView = [UIScrollView new];
scrollView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:scrollView];
[scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
make.top.mas_equalTo(280);
make.size.mas_equalTo(CGSizeMake(350,200));
make.centerX.mas_equalTo(self.view);
}];
UIView *container = [UIView new];
[scrollView addSubview:container];
[container mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo(scrollView);
make.width.equalTo(scrollView);
}];
int count = 15;
UIView *lastView = nil;
for ( int i = 1 ; i <= count ; ++i )
{
UIView *subv = [UIView new];
[container addSubview:subv];
subv.backgroundColor = [UIColor colorWithHue:( arc4random() % 256 / 256.0 )
saturation:( arc4random() % 128 / 256.0 ) + 0.5
brightness:( arc4random() % 128 / 256.0 ) + 0.5
alpha:1];
[subv mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.and.right.equalTo(container);
make.height.mas_equalTo(@(30));
if ( lastView )
{
make.top.mas_equalTo(lastView.mas_bottom);
}
else
{
make.top.mas_equalTo(container.mas_top);
}
}];
lastView = subv;
}
//container這個view起到了一個中間層的作用 能夠自動的計算uiscrollView的contentSize 下面這句很關(guān)鍵
[container mas_makeConstraints:^(MASConstraintMaker *make) {
make.bottom.equalTo(lastView.mas_bottom);
}];
}
