ios objective c todo 应用程序

Question

总体而言，我对 Objective C、Xcode 和 iOS 开发还很陌生。我只是想创建一个简单的 TODO 应用程序，但我没有完成检查。每次我单击一个项目时，我都会在控制台日志中得到一个 (lldb) 和一个线程 1:断点 1.1，我不知道它指的是什么。我的断点出现在最后一行 [tableView deselectRowAtIndexPath:indexPath animated:YES]; 我不确定这里发生了什么。任何帮助将不胜感激。

#import "TDOViewController.h"

@interface TDOViewController () <UIAlertViewDelegate>

@property (nonatomic) NSMutableArray *items;

@end

@implementation TDOViewController

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

    // Handles list of items
    self.items =  @[@{@"name" : @"Take out the trash", @"category" : @"home"}, @{@"name" : @"Shoes", @"category" : @"home"}].mutableCopy;

    // Handles navigation bar
    self.navigationItem.title = @"To-Do List";

    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addNewItem:)];

}

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

#pragma mark - Adding Items
- (void)addNewItem:(UIBarButtonItem *) sender {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"New ToDo Item" message:@"Enter name of new ToDo Item" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Add Item", nil];
    alertView.alertViewStyle = UIAlertViewStylePlainTextInput;
    [alertView show];
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (buttonIndex != alertView.cancelButtonIndex) {
        UITextField * itemNameField = [alertView textFieldAtIndex:0];
        NSString *itemName = itemNameField.text;
        NSDictionary *item = @{@"name" : itemName, @"category" : @"home"};
        [self.items addObject:item];
        [self.tableView insertRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:self.items.count - 1 inSection:0]] withRowAnimation:UITableViewRowAnimationAutomatic];
    }
}

#pragma mark - Table view datasource

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

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

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

    NSDictionary *item = self.items[indexPath.row];

    cell.textLabel.text = item[@"name"];

    if ([item[@"completed"] boolValue]) {
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
    } else {
        cell.accessoryType = UITableViewCellAccessoryNone;
    }

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSMutableDictionary *item = [self.items[indexPath.row] mutableCopy];
    BOOL completed = [item[@"completed"] boolValue];
    item[@"completed"] = @(!completed);

    self.items[indexPath.row] = item;

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryType = ([item[@"completed"] boolValue]) ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}


@end

Answer 1

单击边距中的行号将设置一个断点，该断点会在运行时停止执行该行代码的任何时间。

这对于查找代码中的错误很有用，但如果您不小心放置了它们，就会有点烦人。只需单击蓝色箭头即可禁用断点，单击并将其拖离边缘即可将其删除。

您还可以通过在控制台工具栏中禁用它们来全局关闭断点。