Question

我有一个名为allItems的NSMutableArray，它有以下ProductData个对象。

每个对象都有cid, cname, ctype和cimage。如下所示，json对象没有按顺序排列。但是，cid是订购的指标。

我想知道你是如何根据cid订购的？

 [
  {
    "cid": "2",
    "cname": "Meats",
    "ctype": "main",
    "cimage": "baked_chicken.jpg"
  },
  {
    "cid": "1",
    "cname": "Dips",
    "ctype": "side",
    "cimage": "stuffed_eggplant.jpg"
  },
  {
    "cid": "4",
    "cname": "Sandwiches",
    "ctype": "sand",
    "cimage": "chickenshawarma.jpg"
  },
  {
    "cid": "3",
    "cname": "Appetizers",
    "ctype": "side",
    "cimage": "rice_lentils.jpg"
  },
  {
    "cid": "5",
    "cname": "Desserts",
    "ctype": "dsrt",
    "cimage": "cake.jpg"
  }]

如果我使用sortDescriptior，则部分有效。我面临的问题，在排序时，首先显示cid 1然后cid 10然后cid 2。

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES];
[allItems sortUsingDescriptors:@[sortDescriptor]];

Answer 1

使用带有比较器的排序描述符compare:options:和选项NSNumericSearch：

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES comparator:^(id obj1, id obj2) {
     return [obj1 compare:obj2 options:NSNumericSearch];
}];

甚至更简单：

NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES selector:@selector(localizedStandardCompare:)];

localizedStandardCompare是一个特殊的比较选择器：

只要文件名或其他字符串出现在适合类似Finder的排序的列表和表中，就应该使用此方法。在不同的语言环境下，此方法的确切排序行为是不同的，并且可能在将来的版本中进行更改。此方法使用当前区域设置。

Answer 2

使用此

NSSortDescriptor *aSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid" ascending:YES comparator:^(id obj1, id obj2) {

    if ([obj1 integerValue] > [obj2 integerValue]) {
        return (NSComparisonResult)NSOrderedDescending;
    }
    if ([obj1 integerValue] < [obj2 integerValue]) {
        return (NSComparisonResult)NSOrderedAscending;
    }
    return (NSComparisonResult)NSOrderedSame;
}];
sortedArray = [NSMutableArray arrayWithArray:[unsortedArray sortedArrayUsingDescriptors:@[aSortDescriptor]]];

Answer 3

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"cId" 
    ascending:YES selector:@selector(caseInsensitiveCompare:)];

arrToBeSort = [arrToBeSort sortedArrayUsingDescriptors:[NSArray 
    descriptor]];

这将起作用

Answer 4

    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"cid.intValue" ascending:YES];
[array sortUsingDescriptors:@[sortDescriptor]];

您的“数组”现已在打印后进行排序

打印数组描述：＆lt; __ NSArrayM 0x618000041bf0＆gt;（{cid = 1; cimage =“stuffed_eggplant.jpg”; cname = Dips; ctype = side;}，{cid = 2; cimage =“baked_chicken.jpg”; cname = Meats; ctype = main;}，{cid = 3; cimage =“rice_lentils.jpg”; cname =开胃菜; ctype = side;}，{cid = 4; cimage =“chickenshawarma.jpg”; cname =三明治; ctype = sand;}，{cid = 5; cimage =“cake.jpg”; cname = Desserts; ctype = dsrt;}）

根据一个属性排序数组

4 个答案: