使用定制的NSDictionary的方法，对NSArray进行排序(附：数组排序两种常见方法)

NSArray中存放的是NSDictionary,可以使用策略的方法对NSDictionary进行定制，增加比较的方法。然后调用NSArray的sortUsingSelector方法对数组进行排序,这里使用NSDictionay中的时间对象的时间排序。具体操作如下：
1.定制NSDictionary
XXX.h文件
@interface NSMutableDictionary(myCompare)
-(NSComparisonResult)myCompareMethodWithDict: (NSMutableDictionary*)theOtherDict;
@end
XXX.m文件
#import "CustomDictionary.h"


@implementation NSMutableDictionary(myCompare)
- (NSComparisonResult)myCompareMethodWithDict:(NSMutableDictionary*)anotherDict
{
        NSMutableDictionary *firstDict = self;
        NSDate *firstDate = [firstDict objectForKey: @"browseTime"];
        NSDate *secondDate = [anotherDict objectForKey: @"browseTime"];
        
        //return [firstDate compare: secondDate];
        return [secondDate compare: firstDate];
}
@end

2.使用myCompareMethodWithDict对NSArray进行排序，假设NSArray是从plist文件中读取的NSDictionary对象的数组。
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *plistPath = [NSString stringWithFormat:@"%@/XXX.plist",documentsDirectory];
        NSMutableDictionary * cacheData = [[NSMutableDictionary alloc] initWithContentsOfFile:plistPath];
                [cacheArray sortUsingSelector:@selector(myCompareMethodWithDict:)];//根据时间降序排序
这样，cacheArray就是排序好的数组了。

 

数组排序两种常见方法：

1. 

[myArray.name sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

 

 

2. 

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

NSArray* sortedArray =[myArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];