Question

我制作了一个NSDictionary HospitalDictionary，它包含纬度，经度和距离

NSMutableArray *HospitalArray = [NSMutableArray array];
NSDictionary *HospitalDictionary = [[NSDictionary alloc]init];

NSString *LATITUDE = @"latitude";
NSString *LONGITUDE = @"longitude";
NSString *DISTANCE = @"distance";

for (int i=0; i<=100; i++) { 
// calculations for coordinates and distance are done ....
HospitalDictionary = [NSDictionary dictionaryWithObjectsAndKeys:latitude, LATITUDE,
        longitude, LONGITUDE,[NSNumber numberWithInt:distanceInKm], DISTANCE, nil];

[HospitalArray addObject:HospitalDictionary];
{

然后使用以下代码

来缩短数据

// These line are added to short the Dictionary added to Array List with the Key of Distance 
    NSSortDescriptor *distanceDescriptor = [[NSSortDescriptor alloc] initWithKey:DISTANCE ascending:YES];
    id obj;
    NSEnumerator * enumerator = [HospitalArray objectEnumerator];
    NSArray *descriptors = [NSArray arrayWithObjects:distanceDescriptor, nil];
    NSArray *sortedArray = [HospitalArray sortedArrayUsingDescriptors:descriptors];

    enumerator = [sortedArray objectEnumerator];
    // this will print out the shorted list for DISTANCE
    while ((obj = [enumerator nextObject])) NSLog(@"%@", obj);

    // this will return the object at index 1 
    NSLog(@"Selected array is %@",[sortedArray objectAtIndex:1]);

这是 -

的输出

2012-05-30 08:24:42.784 Hospitals[422:15803] 
sorted array is 
{
    distance = 1;
    latitude = "27.736221";
    longitude = "85.330095";
}

我想只获得ObjectAtIndex的纬度或经度：1为sortedArray。我怎样才能得到特定的价值，即。 latitude of sortedArray不是完整列表。

Answer 1

要访问数组中对象的属性/方法，可以使用以下内容：

NSLog(@"Latitude for object at index 1 is %@",[[sortedArray objectAtIndex:1] latitude]);

使用sortedArrayUsingDescriptors后从NSMutableArray获取值

1 个答案: