关于NSArray 排序的问题

第一种，利用数组的sortedArrayUsingComparator调用 NSComparator ，obj1和obj2指的数组中的对象

NSComparator cmptr = ^(id obj1, id obj2){  
 if ([obj1 integerValue] > [obj2 integerValue]) {  
        return (NSComparisonResult)NSOrderedDescending;  
    }  

    if ([obj1 integerValue] < [obj2 integerValue]) {  
        return (NSComparisonResult)NSOrderedAscending;  
    }  
    return (NSComparisonResult)NSOrderedSame;  
};  
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];  
 //排序前  
 NSMutableString *outputBefore = [[NSMutableString alloc] init];  
 for(NSString *str in sortArray){  
  [outputBefore appendFormat:@"]; } NSLog(@"排序前:%@",outputBefore); [outputBefore release]; //第一种排序 NSArray *array = [sortArray sortedArrayUsingComparator:cmptr]; NSMutableString *outputAfter = [[NSMutableString alloc] init]; for(NSString *str in array){ [outputAfter appendFormat:@"];  
 }  
 NSLog(@"排序后:%@",outputAfter);  
 [outputAfter release];

第二种 排序方法 利用sortedArrayUsingFunction 调用 对应方法customSort，这个方法中的obj1和obj2分别是指数组中的对象

NSInteger customSort(id obj1, id obj2,void* context){  
 if ([obj1 integerValue] > [obj2 integerValue]) {  
        return (NSComparisonResult)NSOrderedDescending;  
    }  

    if ([obj1 integerValue] < [obj2 integerValue]) {  
        return (NSComparisonResult)NSOrderedAscending;  
    }  
    return (NSComparisonResult)NSOrderedSame;  
}  
 NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];  
 //排序前  
 NSMutableString *outputBefore = [[NSMutableString alloc] init];  
 for(NSString *str in sortArray){  
  [outputBefore appendFormat:@"]; } NSLog(@"排序前:%@",outputBefore); [outputBefore release]; NSArray *array = [sortArray sortedArrayUsingFunction:customSort context:nil]; NSMutableString *outputAfter = [[NSMutableString alloc] init]; for(NSString *str in array){ [outputAfter appendFormat:@"];  
 }  
 NSLog(@"排序后:%@",outputAfter);  
 [outputAfter release];  

第三种 利用sortUsingDescriptors调用NSSortDescriptor

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"price" ascending:NO];//其中，price为数组中的对象的属性，这个针对数组中存放对象比较更简洁方便 
  NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:&sortDescriptor count:1];  
  [_totalInfoArray sortUsingDescriptors:sortDescriptors];  
  [_airListView refreshTable:_totalInfoArray];  
  [sortDescriptor release];  
  [sortDescriptors release];

第四种 block 排序

直接上代码：

 NSArray    *array = [NSArray arrayWithObjects:@"71", @"16", @"51", @"104", @"13",@"2",@"1", nil];  


    array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {  
        return (arc4random() % 3) - 1;  
    }];  


   // NSLog(@"array:%@", array); 


    NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id obj1, id obj2) {   


        if ([obj1 integerValue] > [obj2 integerValue]) {   
            return (NSComparisonResult)NSOrderedAscending;   
        }   


        if ([obj1 integerValue] < [obj2 integerValue]) {   
            return (NSComparisonResult)NSOrderedDescending;   
        }   
        return (NSComparisonResult)NSOrderedSame;   


    }];   




sortedArray 是排好序的时间对象数组  


    // 按时间排序 


    NSArray *sortedArray = [srcArrary sortedArrayUsingComparator:^(id obj1, id obj2)  


                            {  


                                NSComparisonResult result = [obj1 compare:obj2];  


                                switch(result)  
                                {  
                                    case NSOrderedAscending:  
                                        return NSOrderedDescending;              
                                    case NSOrderedDescending:  
                                        return NSOrderedAscending;  
                                    case NSOrderedSame:  
                                        return NSOrderedSame;  
                                    default:  
                                        return NSOrderedSame;    
                                } // 时间从近到远（远近相对当前时间而言） 


                            }];  

NSArray    *array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", @"5", nil];  
    array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {  
        return (arc4random() % 3) - 1;  
    }];  
    NSLog(@"array:%@", array);