iOS UITableView - 从 NSDictionary 中进行多项选择

Question

描述:

我有一个 UITableView，每行都加载了 Facebook 好友 json 数据。用户将选择多个 friend ，当按下“完成”按钮时，他们选择的内容将填充到上一页的标签中。

NSMutableArray *friends;
NSDictionary *friendsDict;
NSArray *selectedIndexes;


-viewDidLoad {

//Grab the data from Facebook and put it into an array

friends = [NSMutableArray arrayWithArray:jsonData[@"data"]];

}

-cellForRowAtIndexPath {   

friendsDict = friends[indexPath.row];

cell.textLabel.text = friendsDict[@"name"];

}

-doneButtonPushed {

selectedIndexes = [self.tableView indexPathsForSelectedRows];

//NOW WHAT?

}

问题:

我不清楚如何处理选定的索引。我知道我排序的 friend 列表在“friendsDict”字典中，但如何使用“selectedIndexes”数组从字典中获取所选 friend 的“id”？

我失败的尝试:

-doneButtonPushed {

selectedIndexes = [self.tableView indexPathsForSelectedRows];


//this does not work
NSMutableArray *friendsArray = [friends objectsAtIndexes:selectedIndexes];

}

我已经为此挠头两天了，这真的让我脑袋里塞满了椒盐卷饼。我什至不知道该怎么想了。请各位码神帮忙!

Answer 1

您的代码的主要问题是 NSArray 方法 objectsAtIndexes: 采用 NSIndexSet 类型的参数，但 UITableview 的 indexPathsForSelectedRows 为您提供了一个包含 NSIndexPath 对象的 NSArray。以下是使用 NSArray 的方法:

- doneButtonPushed
{
  selectedIndexes = [self.tableView indexPathsForSelectedRows];
  if (nil == selectedIndexes)
  {
    // No selection
    return;
  }

  // The documentation of indexPathsForSelectedRows talks about
  // "index-path objects" - by this it means that the objects
  // in the array have the type NSIndexPath
  for (NSIndexPath* indexPath in selectedIndexes)
  {
    // Here we get onto familiar ground :-)
    friendsDict = friends[indexPath.row];

    // I don't know the type of the "id" object, so I am just
    // using the generic type id in this example. This is just
    // a coincidence and has nothing to do with the key of
    // your dictionary being "id". If you know that the "id"
    // object is, for instance, an NSString, then change
    // the type of the variable friendId to NSString*.
    id friendId = friendsDict[@"id"];

    // Now do something with friendId ...
  }