AsyncDisplayKit2.0中新功能 Automatic Subnode Management

Automatic Subnode Management(ASM)是AsyncDisplayKit2.0中的新功能，当使用 Layout Transition API进行布局时可以，可以省略掉addSubnode: 或removeFromSupernode，node是否添加或移除由layoutSpecThatFits:中的布局决定, 当需要调整布局时可以调用setNeedsLayout再次调用layoutSpecThatFits:。

AsyncDisplayKit2.0以前的方式

- (instancetype)initWithModelCollectProductLis:(TTCollectProductModel *)product
{
    if (!(self = [super init])) {
        return nil;
    }

    self.backgroundColor = [UIColor whiteColor];
    self.imageViewNode = [[ASNetworkImageNode alloc] init];
    self.imageViewNode.URL = [GlobalFunc urlWithStr:product.ImgUrl];
    self.imageViewNode.defaultImage = [UIImage imageNamed:@"defaultImg"];
    self.imageViewNode.placeholderFadeDuration = 0.3;
    self.imageViewNode.layerBacked = YES;
    
    self.priceTextNode = [[ASTextNode alloc] init];
    self.priceTextNode.maximumNumberOfLines = 1;
    self.priceTextNode.layerBacked = YES;
    
    NSString *price = [NSString stringWithFormat:@"￥%@",[GlobalFunc checkPrice:product.ProductVipPrice.doubleValue]];
    self.priceTextNode.attributedText = [NSAttributedString attributedStringPriceText:price];
    
    self.oldPriceTextNode = [[ASTextNode alloc] init];
    self.oldPriceTextNode.maximumNumberOfLines = 1;
    self.oldPriceTextNode.layerBacked = YES;
    NSString *oldPrice = [NSString stringWithFormat:@"￥%.0f",product.ProductSalePrice.doubleValue];
    self.oldPriceTextNode.attributedText = [NSAttributedString attributedStringOldPriceText:oldPrice];
 
    self.contentTextNode = [[ASTextNode alloc] init];
    self.contentTextNode.maximumNumberOfLines = 2;
    self.contentTextNode.truncationMode = NSLineBreakByTruncatingTail;
    self.contentTextNode.layerBacked = YES;
    self.contentTextNode.attributedText = [NSAttributedString attributedStringProductNameText:product.Productname];
 
    [self.view addSubnode:self.imageViewNode];
    [self.view addSubnode:self.priceTextNode];
    [self.view addSubnode:self.oldPriceTextNode];
    [self.view addSubnode:self.contentTextNode];
    
    return self;
}

- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
    ASRatioLayoutSpec *imageRatioSpec = [ASRatioLayoutSpec ratioLayoutSpecWithRatio:1 child:self.imageViewNode];
    
    ASLayoutSpec *spacer = [[ASLayoutSpec alloc] init];
    spacer.flexGrow = YES;
    
    ASStackLayoutSpec *priceStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal spacing:0 justifyContent:ASStackLayoutJustifyContentSpaceBetween alignItems:ASStackLayoutAlignItemsCenter children:@[self.priceTextNode, spacer, self.oldPriceTextNode]];
    
    ASStackLayoutSpec *contentStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionVertical spacing:10 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsStretch children:@[priceStackSpec, self.contentTextNode]];
    
    ASInsetLayoutSpec *contentinsetSpec = [ASInsetLayoutSpec insetLayoutSpecWithInsets:UIEdgeInsetsMake(0, 10, 10, 10) child:contentStackSpec];
    
    ASStackLayoutSpec *cellStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionVertical spacing:0 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsStretch children:@[imageRatioSpec, contentinsetSpec]];
    return cellStackSpec;
}

AsyncDisplayKit2.0方式

- (instancetype)initWithModelCollectProductLis:(TTCollectProductModel *)product
{
    if (!(self = [super init])) {
        return nil;
    }
    self.automaticallyManagesSubnodes = YES;

    self.backgroundColor = [UIColor whiteColor];
    self.imageViewNode = [[ASNetworkImageNode alloc] init];
    self.imageViewNode.URL = [GlobalFunc urlWithStr:product.ImgUrl];
    self.imageViewNode.defaultImage = [UIImage imageNamed:@"defaultImg"];
    self.imageViewNode.placeholderFadeDuration = 0.3;
    self.imageViewNode.layerBacked = YES;
    
    self.priceTextNode = [[ASTextNode alloc] init];
    self.priceTextNode.maximumNumberOfLines = 1;
    self.priceTextNode.layerBacked = YES;
    
    NSString *price = [NSString stringWithFormat:@"￥%@",[GlobalFunc checkPrice:product.ProductVipPrice.doubleValue]];
    self.priceTextNode.attributedText = [NSAttributedString attributedStringPriceText:price];
    
    self.oldPriceTextNode = [[ASTextNode alloc] init];
    self.oldPriceTextNode.maximumNumberOfLines = 1;
    self.oldPriceTextNode.layerBacked = YES;
    NSString *oldPrice = [NSString stringWithFormat:@"￥%.0f",product.ProductSalePrice.doubleValue];
    self.oldPriceTextNode.attributedText = [NSAttributedString attributedStringOldPriceText:oldPrice];
    
    self.contentTextNode = [[ASTextNode alloc] init];
    self.contentTextNode.maximumNumberOfLines = 2;
    self.contentTextNode.truncationMode = NSLineBreakByTruncatingTail;
    self.contentTextNode.layerBacked = YES;
    self.contentTextNode.attributedText = [NSAttributedString attributedStringProductNameText:product.Productname];
       
    return self;
}

- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
    ASRatioLayoutSpec *imageRatioSpec = [ASRatioLayoutSpec ratioLayoutSpecWithRatio:1 child:self.imageViewNode];
    
    ASLayoutSpec *spacer = [[ASLayoutSpec alloc] init];
    spacer.style.flexGrow = YES;
    
    ASStackLayoutSpec *priceStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionHorizontal spacing:0 justifyContent:ASStackLayoutJustifyContentSpaceBetween alignItems:ASStackLayoutAlignItemsCenter children:@[self.priceTextNode, spacer, self.oldPriceTextNode]];
    
    ASStackLayoutSpec *contentStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionVertical spacing:10 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsStretch children:@[priceStackSpec, self.contentTextNode]];
    
    ASInsetLayoutSpec *contentinsetSpec = [ASInsetLayoutSpec insetLayoutSpecWithInsets:UIEdgeInsetsMake(0, 10, 10, 10) child:contentStackSpec];
    
    ASStackLayoutSpec *cellStackSpec = [ASStackLayoutSpec stackLayoutSpecWithDirection:ASStackLayoutDirectionVertical spacing:0 justifyContent:ASStackLayoutJustifyContentStart alignItems:ASStackLayoutAlignItemsStretch children:@[imageRatioSpec, contentinsetSpec]];
    return cellStackSpec;
}