Question

提示，这是一个按距离对字典进行排序的代码，我需要将一个变量coord传递给detailview，将其分成位置并将标记放在karte上。否则为什么coord给0以及如何将它传递给坐标？

    - (void)viewDidLoad
 {[self setupArray];
 [super viewDidLoad];}

-(void)setupArray{    self.myLocationManager = [[CLLocationManager alloc] init];
    [states setObject: @12 forKey:@"60.050043,30.345783"];
    [states setObject: @11 forKey:@"60.037389,30.322094"];
    [states setObject: @32 forKey:@"60.037329,30.322014"];
    [states setObject: @1 forKey:@"59.957387,30.324681"];
    NSLog(@"%f",betweenDistance);
    NSArray* sortedStates = [states keysSortedByValueUsingComparator: ^(id obj1, id obj2)
                             {
                                 if ([obj1 floatValue] > [obj2 floatValue])
                                 {
                                     return (NSComparisonResult)NSOrderedDescending;
                                 }
                                 if ([obj1 floatValue] < [obj2 floatValue])
                                 {
                                     return (NSComparisonResult)NSOrderedAscending;
                                 }

                                 return (NSComparisonResult)NSOrderedSame;
                             }];
    NSLog(@"%@", sortedStates);
    NSMutableArray* rows = [[NSMutableArray alloc] init];
    for (NSString* key in sortedStates)
    {
        CGFloat distance = [[states objectForKey:key] floatValue];
        [rows addObject:[NSString stringWithFormat:@"Distance is %f km", distance]];
    }
    datasource=rows;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 4;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
     Detail2ViewController *detail = [self.storyboard instantiateViewControllerWithIdentifier:@"detail"];
    [self.navigationController pushViewController:detail animated:YES];
    NSString* coord = sortedStates[indexPath.row];
    NSLog(@"virable coord %@",coord);
}

更新

    2015-04-23 13:25:07.361 gfhfgh[503:7361] 8845784.000000
2015-04-23 13:25:07.363 gfhfgh[503:7361] (
    "59.957387,30.324681",
    "60.037389,30.322094",
    "60.050043,30.345783",
    "60.037329,30.322014"
)
2015-04-23 13:25:07.620 gfhfgh[503:7361] Google Maps SDK for iOS version: 1.9.14591.0
2015-04-23 13:25:10.294 gfhfgh[503:7361] as (null) it is virable coord
2015-04-23 13:25:10.296 gfhfgh[503:7361] my viraible (null)
2015-04-23 13:25:10.296 gfhfgh[503:7361] ((null)) was false: provideAPIKey: should be called at most once

UPDATE2 我使用这个功能，可能是因为它不起作用？

    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];

    }
    // Configure the cell...

    //---------- CELL BACKGROUND IMAGE -----------------------------
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:cell.frame];
    UIImage *image = [UIImage imageNamed:@"LightGrey.png"];
    imageView.image = image;
    cell.backgroundView = imageView;
    [[cell textLabel] setBackgroundColor:[UIColor clearColor]];
    [[cell detailTextLabel] setBackgroundColor:[UIColor clearColor]];

    cell.textLabel.text = [datasource objectAtIndex:indexPath.row];

    //Arrow
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    return cell;
}

Answer 1

在[self setupArray]之前致电[super viewDidLoad]并不是一个好习惯。先叫它。

在- (void)reloadData上加载数据后，尝试调用UITableView的方法- (void)setupArray，告诉tableView的委托您已加载或更新了数据，并希望在tableView上显示它。它应该可以解决你的问题。

仅供参考：在您的情况下，numberOfRowsInSection:应该返回[sortedStates count]以确保点击单元格时，您的应用不会崩溃。

<强>更新

- (void)viewDidLoad
{
    [super viewDidLoad];

    //Call setup array after [super viewDidLoad]
    [self setupArray];
}

-(void)setupArray {

    //Do all your setupArray stuff

    //Now update the table contents
    [yourTableView reloadData];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    //Use [sortedStates count] here to be sure your app will not crash later
    return [sortedStates count];
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    Detail2ViewController *detail = [self.storyboard instantiateViewControllerWithIdentifier:@"detail"];
    [self.navigationController pushViewController:detail animated:YES];
    NSString* coord = sortedStates[indexPath.row];
    NSLog(@"virable coord %@",coord);
}

更新2

我想我找到了原因！你有一个名为sortedStates的实例变量，但在- (void)setupArray内你声明一个同名的局部变量，这就是你没有在其他方法中获取值的原因。

尝试更改

NSArray* sortedStates = [states keysSortedByValueUsingComparator: ^(id obj1, id obj2) { 
    //stuff
}];

与

//without "NSArray *"
sortedStates = [states keysSortedByValueUsingComparator: ^(id obj1, id obj2) { 
    //stuff
}];

Answer 2

因为sortedStates [indexPath.row];将导致NSDictionary。所以代码应该是：

NSDictionary *coord = sortedStates[indexPath.row];

将此值传递给detailViewController并在那里提取坐标。

indexPath.row总是给出零（为什么不工作？）

2 个答案: