Get data from a PList into UITableView?

问题:

I want to maintain a list of records, for each one I maintain the same type of data. I want to use this data in 2 different places:

1. UITableView that takes from each record the "Name" value
2. UIViewController that takes all the data to use in different fields.

I assume I should be using a plist to store the data; I also assume that the object that should be receiving the data for the UITableView is NSArray so I can use the cellForRowAtIndexPath method to create the table automatically.

So i created the plist "PLForArr.plist":

It seems that i can only get a NSDictionary when calling the plist using

NSString *path = [[NSBundle mainBundle] pathForResource:@"PLForArr" ofType:@"plist"];
NSArray * myArr = [[NSArray alloc] initWithContentsOfFile:path]; //doesn't work...
NSDictionary * myDict = [[NSDictionary alloc] initWithContentsOfFile:path]; //does work, but who to I make a NSArray out of it / or get the data from here to the UITableView?

I understand that i don't understand something basic here... Can someone take me step by step on:

1. How to keep the data - should I use plist or something else? Should I have a main record of type array (as I did on the example plist here) or can I just keep it as these Dictionaries without the unnecessary MyArr that I used considering the UITableView end target?
2. How to call the data - Is there a way to get it into a NSArray or must it get into a NSDictionary?
3. How to call it into the the UITableView - Can I fill in the lines using a NSDictionary?

回答1:

1. Storing the data is an Array or a Dictionary is up to you. But if you want to make changes to it over time you can't store it in the main bundle.

2. Your pList file is a dictionary that contains an array. See code example below.

3. You will have to store the dictionary in an array for the data source for your table. See code example below.

Assuming that your UITableView's data source is called tableArray. You can use tableArray to fill in the information in the table and your view. Oh yeah,

NSString *path = [[NSBundle mainBundle] pathForResource:@"PLForArr" ofType:@"plist"];
NSDictionary *myDict = [[NSDictionary alloc] initWithContentsOfFile:path];

NSArray *myArray = [myDict objectForKey:@"MyArray"];
self.tableArray = [myArray copy];
[myArray release];
[myDict release];

This goes in tableView: cellForRowAtIndexPath:

cell.text = [[tableArray objectAtIndex:row]objectForKey:@"Obj Name"];

回答2:

1. Storing your data either in a dictionary, or in an array is up to you. Depending on the kind of data you have, you will consider storing unordered collection of objects (dictionary), accessing the entries with keys; or rather in ordered collection (array), using numeric indexes.

2. It's fine to get arrays from property list files, but the root (top level) object is a dictionary (in the screenshot, "MyArr" isn't the top-level object, it is the key for accessing your array in the top-level dictionary). To get your array from it, simply alloc/init the plist dictionary the way you did, and access the array entry using its key ([myDict objectForKey:@"MyArr"]). Otherwise make sure you set the root object of the property list to be an array, and retry NSArray's initWithContentsOfFile:

3. The real question seems to be How can I fill the cells with my data ? The table views ask its delegate and dataSource about how many sections, rows in a section, to display. Based on these numbers, it will ask the dataSource for cells. Once again depending on the storage type you've chosen, you will implements these methods a little bit differently, but the concepts remain.

You will probably want to read documentation about :

• Property List
• Table views