NSSortDescriptor将数字排序为字符串？ [英] NSSortDescriptor sort with number as string?

问题描述

得到一个充满字典的数组喜欢这样：

Got a an Array full of dictionary likes this:

(
   { order = "10";
     name = "David"
   };
   { order = "30";
     name = "Jake";
   };
   { order = "200";
     name = "Michael";
   };
)

当我像下面的代码一样使用NSSortDescriptor时，它只对第一个char进行排序，因此200低于30.我当然可以将order对象更改为NSNumber而不是字符串，它可以工作。但有没有办法将字符串排序为int值而不更改源对象？

When i'm using NSSortDescriptor like the code below it only sorts regarding to the first char so 200 is lower then 30. I can of course change the "order" object into a NSNumber instead of string and it would work. But is there a way to sort a string as int values without changing the source object?

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"norder"  ascending:YES];
[departmentList sortUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];

更新：

感谢bandejapaisa。

Thanks to bandejapaisa.

这是适用于iOS 5的工作版本（Xcode，其中包括编译）。

Here is the a working version for iOS 5 (Xcode where compalining).

NSArray *sortedArray;
sortedArray = [departmentList sortedArrayUsingComparator:(NSComparator)^(id a, id b) {
    NSNumber *num1 = [NSNumber numberWithInt:[[a objectForKey:@"norder"] intValue]];
    NSNumber *num2 = [NSNumber numberWithInt:[[b objectForKey:@"norder"] intValue]];

    return [num1 compare:num2];
}];
departmentList = [sortedArray mutableCopy];

推荐答案

也许使用比较器排序，或者其中一个其他排序方法：

Maybe sort using a comparator instead, or one of the other sorting methods:

NSArray *sortedArray = [someArray sortedArrayUsingComparator:^(id obj1, id obj2) {
  NSNumber *num1 = [NSNumber numberWithInt:[obj1 intValue]];
  NSNumber *num2 = [NSNumber numberWithInt:[obj2 intValue]];
  return (NSComparisonResult)[rank1 compare:num2];
}];

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