如何在Swift中的Json文件中显示多个TableView？

Question

What I want to do is to display my information from a Json file into my TableView on Xcode(Swift). Here is an example for I want to to:

I want to retrieve my json data from countries, cities and some aditional information from cities. In the first screen I want to display the name of the countries in a TableView:

• Brazil
• Germany
• France
• USA
• Argentina
• etc...

Then, when I clic in a cell of one country (USA for example) I want to open a new TableView that contains all the states (or cities) from USA. So I clic on USA and I have the following information in the second screen:

• Florida
• New York
• California
• Nevada
• etc...

And finally when I clic in some state (or city), for example in New York I want to display some aditional information from the state I have selected (New York). So in the third screen I have:

"New York is an awesome city...etc"

I want to navegate from one tableview to another, so I don´t know how to add the "back" button on the top of the screen, for each tableview. The countries and the city i want to display in different cells, so I can clic on them and display the information.

Here is my json example:

[
    {
        "country": "Brazil",
        "city": [
            "Sao Paulo",
            "Rio de Janeiro"
        ]
    },
    {
        "country": "Germany",
        "city": [
            "Berlin",
            "Frankfurt"
        ]
    },
    {
        "country": "France",
        "city": [
            "Paris",
            "Marselle"
        ]
    },
    {
        "country": "USA",
        "city": [
            "Florida",
            "New York",
            "California",
            "Nevada"
        ]
    },
    {
        "country": "Argentina",
        "city": [
            "Buenos Aires",
            "Mendoza",
            "La Plata"
        ]
    },
    {
        "country": "England",
        "city": [
            "London",
            "Manchester",
            "Liverpool"
        ]
    }
]

Please can anybody help me to do this? How can I do it? Thanks a lot!

Answer 1

This is pretty so simple, and most of the work is done by iOS and Xcode, you won't do so much work.

You need to get some know how in these topics: UITableView , UINavigationController and Storyboards .

You can follow this tutorial and you will find that it's a very easy task.

Here's the steps:

1. First of all, you need to design the app UI in a storyboard. You will create a scene view for the Countries screen, and another one for the Cities, and another one for the Cities Details screen.
2. Embed the first screen in UINavigationController , so that you get all the navigation stuff for free.
3. Show the countries data in Countries screen table view.
4. Make a segue from the Countries table view to Cities screen. So that when a country is selected, its cities is shown in the cities screen.
5. Pass the selected country object to the Cities screen using the method prepareForSegue (described in the tutorial I mentioned above).
6. Show the list of cities in the cities screen.
7. Do the same when navigating from Cities screen Cities Details screen.

Please read the tutorial first, then you will understand very well the steps I mentioned. It's pretty simple task that take around 1 hour to do.

Answer 2

Your table view data source methods are designed for this use case:

Use a stored NSIndexPath *selected to track the ui state in didSelectRow

Add an if statment to your data source methods, if (selected) to cellForRow and numberOfRows

In the selected == nil logic branch, return dict.keys.count for number of rows and return dict.keys[indexPath.row][@"country"] as the title for your row

In the selected != nil branch, return dict[dict.keys[selected.row][@"cities"].keys.count for number of rows and return dict[dict.keys[selected.row]][@"cities"][indexPath.row] as the title for your row