ios - UITableView 中所有级别的项目的多级类别

Question

我必须使用下面的 JSON 响应创建一个 UITableView ( Array )。我还没有这方面的代码，但很想知道如何拆分这个数组以适应所有级别的类别和项目。

 {
   "result":{
      "products":[
         {
            "id":"4",
            "product_code":"PR04",
            "title":"Product1",
            "franchisee_id":"118"
         }
      ],
      "categories":[
         {
            "id":"8",
            "name":"Category1"
         },
         {
            "id":"20",
            "name":"Category2",
            "products":[
               {
                  "id":"9",
                  "product_code":"PR07",
                  "title":Product2,
                  "franchisee_id":"118"
               }
            ]
         }
      ]
   }
}

我想达到以下结果:

• 项目
• 类别 1 > 项
• 类别 2 > 项

单击类别时，它会滑动到该类别中的产品。真的很喜欢这方面的一些指导。有些产品不会分类。就像上面的例子。

Answer 1

嗯....

1. 您需要解析 JSON 文件。您可以轻松地通过谷歌搜索一些教程，但是 here is a decent one .

2. 接下来您需要设置一个 UITableView 来加载项目。 another good tutorial on UITableViews

3. 然后您将需要学习如何在 UIViewController 之间传递数据。 Tutorial .

因此您在代码中的步骤将是:

1. 解析 JSON 以分离所有元素。
2. 设置一个 UITableView 来显示顶级元素。
3. 创建第二个 UITableViewController 以在选择顶级项目后将其推送到。
4. 为第二个 UITableViewController 设置一个自定义初始化程序，这样您就可以将相关数据从您解析 JSON 的第一个 View Controller 传递给它。

我假设您正在寻找一堆关于如何执行此操作的代码，但这并不好玩 :)

如果您遇到任何问题，请告诉我，我很乐意提供帮助。

编辑:

我知道我说过我不会转储代码，但我还有一些额外的时间。

创建一个名为 ProductObject 的 NSObject 子类，并使 .h 如下所示:

#import <Foundation/Foundation.h>

@interface ProductObject : NSObject
@property NSString *productCode, *productTitle, *franchiseId, *productId;
@end

不要对.m做任何事情

---

创建另一个名为 CategoryObject 的 NSObject 子类，并使 .h 如下所示:

#import <Foundation/Foundation.h>

@interface CategoryObject : NSObject
@property NSString *categoryName, *categoryId;
@property NSArray  *products;
@end

同样，不需要对 .m 做任何事情。

---

现在，在您要显示 UITableView 的类中，将显示 Products 和 Categories(这都在 .m、.h 为空):

#import "ViewController.h"
#import "CategoryObject.h"
#import "ProductObject.h"

@interface ViewController ()

//Hooked in from IB
@property (weak, nonatomic) IBOutlet UITableView *table;

//Our UITableView data source
@property NSMutableDictionary *tableObjects;

@end


@implementation ViewController


/**
 Parses a the local JSON file
 */
- (void)parseJSON {
    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"json"];

    //création d'un string avec le contenu du JSON
    NSString *myJSON = [[NSString alloc] initWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];

    NSError *error;
    NSDictionary *topLevleJSON = [NSJSONSerialization JSONObjectWithData:[myJSON dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&error];

    if (error) {
        NSLog(@"Error serializing JSON: %@", error.localizedDescription);
        return;
    }


    NSArray *products   = topLevleJSON[@"products"];
    NSArray *categories = topLevleJSON[@"categories"];

    //Use a NSDictonary so that it contains an NSArray of ProductObjects for the "Products" key, and an array of CategoryObjects for the "Category" key.
    self.tableObjects = [NSMutableDictionary new];

    //Parse all the products
    NSMutableArray *productsInJSON = [NSMutableArray new];
    [products enumerateObjectsUsingBlock:^(NSDictionary *productObject, NSUInteger idx, BOOL *stop) {
        ProductObject *product = [self createProductObjectFromDictionary:productObject];
        [productsInJSON addObject:product];
    }];

    //Set the array of ProductObjects for the key @"Products"
    [self.tableObjects setObject:productsInJSON forKey:@"Products"];


    //Parse all the categories
    NSMutableArray *categoriesInJSON = [NSMutableArray new];
    [categories enumerateObjectsUsingBlock:^(NSDictionary *categoryObject, NSUInteger idx, BOOL *stop) {
        CategoryObject *category = [self createCategoryObjectFromDictionary:categoryObject];
        [categoriesInJSON addObject:category];
    }];

    //Set the array of CategoryObjects for key @"Categories"
    [self.tableObjects setObject:categoriesInJSON forKey:@"Categories"];

    [self.table reloadData];
}

/**
 Creates a ProductObject from an NSDictonary.

 @param dictionary The dictonary describing the Product parsed from JSON

 @return A pretty formatted ProductObject
 */
- (ProductObject*)createProductObjectFromDictionary:(NSDictionary*)dictionary {
    ProductObject *product = [ProductObject new];
    product.productTitle = dictionary[@"title"];
    product.productCode  = dictionary[@"product_code"];
    product.franchiseId  = dictionary[@"franchisee_id"];
    product.productId    = dictionary[@"id"];

    return product;
}


/**
 Creates a Category from an NSDictionary

 @param dictionary The dictonary describing the Category parsed from JSON

 @return A pretty formatted CategoryObject
 */
- (CategoryObject*)createCategoryObjectFromDictionary:(NSDictionary*)dictionary {

    CategoryObject *category = [CategoryObject new];
    category.categoryId   = dictionary[@"id"];
    category.categoryName = dictionary[@"name"];

    //Check to see if the "products" key exist for the category, if we don't check and just look for it, we will get a crash if it doesn't exist.
    if ([[dictionary allKeys] containsObject:@"products"]) {
        NSArray *categoryProducts = dictionary[@"products"];

        //Parse all the Products for the Category.
        NSMutableArray *categoryProductsFormatted = [NSMutableArray new];
        [categoryProducts enumerateObjectsUsingBlock:^(NSDictionary *productObject, NSUInteger idx, BOOL *stop) {
            ProductObject *product = [self createProductObjectFromDictionary:productObject];
            [categoryProductsFormatted addObject:product];
        }];

        category.products = [NSArray arrayWithArray:categoryProductsFormatted];
    }
    else {
        category.products = nil;
    }

    return category;
}


#pragma mark -
#pragma mark - UITableView delegate

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return [[self.tableObjects allKeys] count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    //Get the key for this section
    NSString *key = [[self.tableObjects allKeys] objectAtIndex:section];

    //Return the number of objects for this key.
    return [(NSArray*)[self.tableObjects objectForKey:key] count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    return [[self.tableObjects allKeys] objectAtIndex:section];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CellIdentifier"];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellIdentifier"];
    }

    //Get all the NSArray associated with this section, which will be an array of ProductObjects or an array of CategoryObjects
    NSString *key = [[self.tableObjects allKeys] objectAtIndex:indexPath.section];
    NSArray *sectionobjects = (NSArray*)[self.tableObjects objectForKey:key];

    id object = [sectionobjects objectAtIndex:indexPath.row];

    //Set the cell text based on what kind of object is returned
    if ([object isKindOfClass:[ProductObject class]]) {
        cell.textLabel.text = [(ProductObject*)object productTitle];
    }

    else if ([object isKindOfClass:[CategoryObject class]]) {
        cell.textLabel.text = [(CategoryObject*)object categoryName];
    }

    return cell;
}

#pragma mark -
#pragma mark - UITableView delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {


    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    NSString *key = [[self.tableObjects allKeys] objectAtIndex:indexPath.section];
    NSArray *sectionobjects = (NSArray*)[self.tableObjects objectForKey:key];

    id object = [sectionobjects objectAtIndex:indexPath.row];

    //They selected a product
    if ([object isKindOfClass:[ProductObject class]]) {

        ProductObject *product = (ProductObject*)object;

        NSLog(@"%@", product.productTitle);
        NSLog(@"%@", product.productCode);
        NSLog(@"%@", product.productId);
    }


    //They selected a Category
    else if ([object isKindOfClass:[CategoryObject class]]) {

        //Check to see if the CategoryObject has any ProductObjects associated with it
        if ([(CategoryObject*)object products]) {

            //Now you will need to pass array of ProductObjects this along to your next view controller.
            NSArray *cateogryProducts = [(CategoryObject*)object products];


            //For demonstration purposes, i'll run through and print out all the Products for this Category
            [cateogryProducts enumerateObjectsUsingBlock:^(ProductObject *product, NSUInteger idx, BOOL *stop) {
                NSLog(@"%@", product.productTitle);
                NSLog(@"%@", product.productCode);
                NSLog(@"%@", product.productId);
            }];
        }

    }

}



- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    //Start parsing the JSON
    [self parseJSON];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

---

编辑:

如果您想像 Accordion 一样打开和关闭表格的某些部分，请查看 Apple 的相同代码:Table View Animations and Gestures .