故事板使用表视图和来自plist的数据进行Segue

Question

我的数据在plist中，这是一个按字母顺序排列的城市名称列表，它还包含一个电话号码，当用户选择一个行（城市名称）时，该电话号码将被推送到信息视图并显示表视图。我已经从使用NSMutableArray到现在的plist来保存我的数据，现在我的segue无法正常工作。构建在模拟器中成功，但在单击表格单元格时会引发错误。有什么想法为什么这不正常？我在我的cellForRowAtIndex ..或我的prepareForSegue方法中认为它是一个变量。

#import "CityListTableViewController.h"

@interface CityListTableViewController () 

@end

@implementation CityListTableViewController

@synthesize cities, sections;

-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

//ensure this is the Segue which is leading to the info view
if ([segue.identifier isEqualToString:@"ShowInfo"]) 
{
    //now setup info controller so it can function...
    //get the info instance
    InfoViewController *ivc = [segue destinationViewController];
    //get the selected row and city name from it
    NSIndexPath *path = [self.tableView indexPathForSelectedRow];
    //inform the info view of the selected city
    int row = [path row];
    City *c = [cities objectAtIndex:row];
    [ivc setCurrentCity:[cities objectAtIndex:path.row]];
    ivc.currentCity = c;
}   

}


- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
        // Custom initialization
    }
return self;
}


- (void)viewDidLoad {



self.cities = [NSMutableArray arrayWithContentsOfFile:[[NSBundle mainBundle]  pathForResource:@"cities" ofType:@"plist"]];
self.sections = [[NSMutableDictionary alloc] init];

BOOL found;

// Loop through the cities and create our keys
for (NSDictionary *city in self.cities)
{        
    NSString *c = [[city objectForKey:@"city"] substringToIndex:1];

    found = NO;

    for (NSString *str in [self.sections allKeys])
    {
        if ([str isEqualToString:c])
        {
            found = YES;
        }
    }

    if (!found)
    {     
        [self.sections setValue:[[NSMutableArray alloc] init] forKey:c];
    }
}

// Loop again and sort the cities into their respective keys
for (NSDictionary *city in self.cities)
{
    [[self.sections objectForKey:[[city objectForKey:@"city"] substringToIndex:1]]  addObject:city];
}    

// Sort each section array
for (NSString *key in [self.sections allKeys])
{
    [[self.sections objectForKey:key] sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"city" ascending:YES]]];
}    

[super viewDidLoad];
}


- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}



- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{
return [[self.sections allKeys] count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{    
return [[[self.sections allKeys]  sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)] objectAtIndex:section];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
return [[self.sections valueForKey:[[[self.sections allKeys]    sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)] objectAtIndex:section]] count];
}


- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView 
{
return [[self.sections allKeys]   sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
}


// Customize the appearance of table view cells.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{

static NSString *CellIdentifier = @"DeptCell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}

NSDictionary *current = [[self.sections valueForKey:[[[self.sections allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)] objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row];


cell.textLabel.text = [current objectForKey:@"city"];    


return cell;
}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];

}
@end