Question

我正在开发一个在主视图中显示rss供稿的应用。它有一个详细视图，显示该rss供稿项的Web视图。我正在向左侧添加一个滑出的导航栏，它将打开。当我尝试启动它时，我的应用程序不断崩溃。这是我的代码。我还使用了一个名为SWRevealViewController的第三方库，它提供了滑出机制。

我的MasterViewController.h有一个插座，用于切换滑出菜单。我宣称它是“sidebarButton”。

这是我的MasterViewController.m

#import "JSSMasterViewController.h"
#import "SWRevealViewController.h"
#import "JSSDetailViewController.h"

@interface JSSMasterViewController () {
    NSMutableArray *_objects;
}
@end

@implementation JSSMasterViewController

- (void)awakeFromNib
{
    [super awakeFromNib];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.navigationItem.leftBarButtonItem = self.editButtonItem;

    // Change button color
    _sidebarButton.tintColor = [UIColor colorWithWhite:0.96f alpha:0.2f];

    // Set the side bar button action. When it's tapped, it'll show up the sidebar.
    _sidebarButton.target = self.revealViewController;
    _sidebarButton.action = @selector(revealToggle:);

    // Set the gesture
    [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)insertNewObject:(id)sender
{
    if (!_objects) {
        _objects = [[NSMutableArray alloc] init];
    }
    [_objects insertObject:[NSDate date] atIndex:0];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}

#pragma mark - Table View

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return _objects.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    NSDate *object = _objects[indexPath.row];
    cell.textLabel.text = [object description];
    return cell;
}

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        [_objects removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
    } else if (editingStyle == UITableViewCellEditingStyleInsert) {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
    }
}

/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/

/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the item to be re-orderable.
    return YES;
}
*/

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

}

@end

构建总是成功但是当应用程序在iOS模拟器中启动时它会崩溃。

似乎得到错误的部分是以下代码：

    - (void)insertNewObject:(id)sender
{
    if (!_objects) {
        _objects = [[NSMutableArray alloc] init];
    }
    [_objects insertObject:[NSDate date] atIndex:0];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}

断点一直停止的地方是：

// Set the gesture
    [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];

我的控制台记录的唯一错误是：

*** -[__NSArrayM insertObject:atIndex:]: object cannot be nil

我有什么问题吗？谢谢你的帮助！

Answer 1

该错误消息告诉您self.revealViewController.panGestureRecognizer为零，这可能是由self.revealViewController为零造成的。

*** - [__ NSArrayM insertObject：atIndex：]：对象不能为零？我一直收到这个错误

1 个答案: