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c#listlinqunity-game-engineuielement

C# Unity dropdown, on change calling a function, function query list return matching list items


One of those simple ones where my head is just blocked. I'm used to coding in php and mysql and I just can't figure out the simple syntax in c#.

I have a list which holds business listings as my Item class is structured below. I have a dropdown in unity and onchange I have the category ID of the selected item using this :

private void myDropdownValueChangedHandler(Dropdown target) {

int selectedIndex = myDropdown.value;

    //LOAD THE ID FROM THE CATS LIST
    string theName = myDropdown.options[selectedIndex].text;
    var result = loadJSONCats.instance.fetchItemIDByName(theName);

}


public Item fetchItemByID(int id){

        for (int i = 0; i < myList.Count; i++) {
            if(myList[i].ID == id){
               return myList[i];
            }

        }
        return null;
 }

I now need to look for the matching listings in mylist.

In mysql I would SELECT * from mylist where term_id IN(id);

I need a new list creating from the result so I can loop through the items found and instantiate a prefab which will be in a vertical list element with the correct data in each vertical row.

My Item class

public class Item {

    public int ID {get; set;}
    public string post_modified {get; set;}
    public string post_title {get; set;}
    public string post_type {get; set;}
    public string guid {get; set;}
    public string Terms_IDs {get; set;}
    public string City {get; set;}
    public string Latitude {get; set;}
    public string LogoID {get; set;}
    public string Longitude {get; set;}

    //public Item(int id, string post_mod, string post_title, string post_type, string terms, string meta, string guid){
    public Item(int id, string post_mod, string post_title, string post_type, string guid, string terms, string city, string latitude, string logoID, string longitude){

        this.ID = id;
        this.post_modified = post_mod;
        this.post_title = post_title;
        this.post_type = post_type;
        this.guid = guid;
        this.Terms_IDs = terms;
        this.City = city;
        this.Latitude = latitude;
        this.LogoID = logoID;
        this.Longitude = longitude;

    }

}

The terms IDs are a string as my json code was easier to translate that way.

This is the function I'm stuck on,

public Item findItemsByIDs(int termID){



}

I need to pass in the id for the item.terms and find all the matching list items in :

    public List<Item> myList = new List<Item>();

then return a list with the right data and call the prefab instantiation to fill out a vertical grid with the rows filled by the results in the query.

I'm new to LINQ and getting confused between that and lamba.

It's just one of those things I cold do so easily in sql normally but being new to c# im going all over the internet and getting nowhere fast.

Help Appreciated.

Here's the constructor :

void ConstructListingDatabase(){

        for (int i = 1; i < itemData.Count; i++) {
            myList.Add(new Item((int)itemData[i][0], itemData[i][1].ToString(), itemData[i][2].ToString(), itemData[i][3].ToString(), itemData[i][4].ToString(), itemData[i][5].ToString(), itemData[i][6].ToString(), itemData[i][7].ToString(), itemData[i][8].ToString(), itemData[i][9].ToString()));
        }

  }

Solution

  • By using Linq you can get the Items that contain the same Id

    public List<Item> findItemsByIDs(int termID){
    
        return myList.Where(i => i.Terms_IDs.Split(',').Contains(termID.ToString())).ToList();
    
    }
    

    This would return all Items in your list that have Terms_IDs that contain termID

    Don't forget to add

    using System.Linq;