Wiring the table view = crash


Been going great up until now. Simulator crashes with the breakpoint at the @property (strong, nonatomic) UIWindow *window; line in AppDelegate.h
Xcode 6.1

Guidance highly appreciated.


//  AppDelegate.h
//  iTahDoodle
//  Created by on 11/20/14.
//  Copyright (c) 2014 . All rights reserved.

#import <UIKit/UIKit.h>

// Declare a helper function that we will use to get a path to the location on disk where we can save the to-do list
NSString *docPath(void);

@interface AppDelegate : UIResponder <UIApplicationDelegate, UITableViewDataSource>
    UITableView *taskTable;
    UITextField *taskField;
    UIButton *insertButton;
    NSMutableArray *tasks;

- (void)addTask:(id)sender;

@property (strong, nonatomic) UIWindow *window;



//  AppDelegate.m
//  iTahDoodle
//  Created by on 11/20/14.
//  Copyright (c) 2014 . All rights reserved.

#import "AppDelegate.h"

@interface AppDelegate ()


// Helper function to fetch the path to our to-do data stored on disk
NSString *docPath()
    NSArray *pathList = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    return [[pathList objectAtIndex:0] stringByAppendingPathComponent:@"data.td"];

@implementation AppDelegate

#pragma mark - Application delegate callbacks

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Attempt to load an existing to-do dataset from an array stored to disk.
    NSArray *plist = [NSArray arrayWithContentsOfFile:docPath()];
    if (plist) {
        // If there was a dataset available, copy it into our instance variable.
        tasks = [plist mutableCopy];
    } else {
        // Otherwise just create an empty one to get us started.
        tasks = [[NSMutableArray alloc] init];

    // Is tasks empty?
    if ([tasks count] == 0) {
        // Put some strings in it
        [tasks addObject:@"Walk the dogs"];
        [tasks addObject:@"Feed the hogs"];
        [tasks addObject:@"Chop the logs"];
    // Create and configure the UIWindow instance
    // A CGRect windowFrame is a struct with an origin (x.y) and size (width,height)
    CGRect windowFrame = [[UIScreen mainScreen] bounds];
    UIWindow *theWindow = [[UIWindow alloc] initWithFrame:windowFrame];
    [self setWindow:theWindow];
    // Define the frame rectangles of the three UI elements
    // CGRectMake() creates a CGRect from (x, y, width, height)
    CGRect tableFrame = CGRectMake(0, 80, 320, windowFrame.size.height -100);
    CGRect fieldFrame = CGRectMake(20, 40, 200, 31);
    CGRect buttonFrame = CGRectMake(228, 40, 72, 31);
    // Create and configure the table view
    taskTable = [[UITableView alloc] initWithFrame:tableFrame
    [taskTable setSeparatorStyle:UITableViewCellSeparatorStyleNone];
    // Make this object the table view's dataSource
    [taskTable setDataSource:self];
    // Create and configure the text field where new tasks will be typed
    taskField = [[UITextField alloc] initWithFrame:fieldFrame];
    [taskField setBorderStyle:UITextBorderStyleRoundedRect];
    [taskField setPlaceholder:@"Type a task, tap Insert"];
    // Create and configure a rounded rect Insert button
    insertButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [insertButton setFrame:buttonFrame];
    // Buttons behave using a target/action callback
    // Configure the INsert button's action to call this object's -addTask: method
    [insertButton addTarget:self
    // Give the button a title
    [insertButton setTitle:@"Insert"
    // Add our three UI elements to the window
    [[self window] addSubview:taskTable];
    [[self window] addSubview:taskField];
    [[self window] addSubview:insertButton];
    // Finalize the window and put it on the screen
    [[self window] setBackgroundColor:[UIColor whiteColor]];
    [[self window] makeKeyAndVisible];
    return YES;

#pragma mark - Table View management

- (NSInteger)tableView:(UITableView *)tableView
    // Because this table view only has one section, the number of rows in it is equal to the number of items in our tasks array
    return [tasks count];

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    // To improve performance, we reconfigure cells in memory that have scrolled off the screen and hand them back with
    // new contents instead of always creating new cells
    // First, we check to see if there's a cell available for reuse
    UITableViewCell *c = [taskTable dequeueReusableCellWithIdentifier:@"Cell"];
    if (!c) {
        // ... and only allocate a new cell if none are available
        c = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
    // Then we (re)configure the cell based on the model object, in this case our todoItems array
    NSString *item = [tasks objectAtIndex:[indexPath row]];
    [[c textLabel] setText:item];
    // and hand back to the table view the properly configured cell
    return c;

- (void)applicationWillResignActive:(UIApplication *)application {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.

- (void)applicationDidEnterBackground:(UIApplication *)application {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.

- (void)applicationWillEnterForeground:(UIApplication *)application {
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.

- (void)applicationDidBecomeActive:(UIApplication *)application {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

- (void)applicationWillTerminate:(UIApplication *)application {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.



I have tested your code with a single view application, without the storyboard and launch screen files, on the iPad 2 simulator.

It works, but the following method is missing:

[code]- (void)addTask:(id)sender
NSLog (@"%s", func);

[tasks addObject:taskField.text];
[taskField resignFirstResponder];
[taskTable reloadData];



Hi ibex10,

I tried adding your method to my AppDelegate.m but I ended up with the same crash in the simulator. I created a new project, and copied and pasted my code snippets from the original into the new one, and now the application launches as expected.

Thanks for your help.

B. Love.