如何在NSMutableDictionary中为一个对象设置多个值？

Question

I would like to story many items in one object (the name of the user, their photo, and the time the photo was taken). I have tried to use three different arrays to do this and it somewhat works, however since I am loading this into a tableview its not the best way to do this. I am thinking about using a NSMutableDictionary but I can't seem to do it. Any help would be appreciated!

Answer 1

What you want to do is create a User Entity (Swift/Objective-C Class) with username, photo and photoTime fields.

Create the users, put drop them in an array and then read from it while you are creating the table in cellForRowAtIndexPath .

@interface User : NSObject

@property (nonatomic, retain) NSString *userName;
@property (nonatomic, retain) NSString *photoURL;
@property (nonatomic, retain) NSString *photoTime;

@end

Then somewhere within your code where you create users...

NSMutableArray *usersArray= [[NSMutableArray alloc] init];

User *user= [[Useralloc] init];
user.userName=@"someUserName"
user.photoURL=@"http://somephotourl.com";
user.photoTime=@"1231232132121";

[usersArray addObject:user];

Answer 2

You can do like this.

NSDictionary *dic = [[NSDictionary alloc]initWithObjectsAndKeys:
                     @"Jone",@"UserName",
                     @"Jone.png",@"Photo",
                     [NSDate date],@"Time",nil];

NSMutableArray *userArray = [[NSMutableArray alloc] init];
[userArray addObject:dic];
//NSLog(@"%@",userArray);

for (int i=0; i<userArray.count; i++) {
    NSDictionary *userDictionary = [userArray objectAtIndex:i];
    NSLog(@"UserName:%@",[userDictionary valueForKey:@"UserName"]);
    NSLog(@"Photo:%@",[userDictionary valueForKey:@"Photo"]);
    NSLog(@"Time:%@",[userDictionary valueForKey:@"Time"]);
}

Note:I think you need to use "NSMutableArray" of NSDictionary. if you all user property (username,photo,time...) are unpredictable the only you need to use NSMutableDictionary.

Answer 3

The data structure behind a UITableView is usually NSArray or a list of some kind. Each object in the array should represent a row in the table.
Following this pattern your structure should look like that:

var users = [User]()

struct User {
    let name: String
    let photo: UIImage
    let date: NSDate
}

// This struct could also be a dictionary
var user = [String: AnyObject]()
user["name"] = ..
user["photo"] = ..
user["date"] = ...

Instantiate User objects and add them to the users array when appropriate.
Your UITableView should find the correct user and update the cell accordingly in the dataSource method:

func tableView(_ tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = .. // Dequeue cell

    let user = users[indexPath.row] // Get the user for this row
    cell.textLabel.title = user.name // Update cell properties
    // etc..

    // OR using a dictionary
    cell.textLabel.title = user["name"]
    // etc..

    return cell