我正在编写一个简单的清单应用程序。我有两个 UIViewControllers。第一个在 UITableView 中显示清单。我正在使用 UIBarButtonItem 将第二个视图推送到堆栈上以添加新任务。所有任务都保存在一个数组中。
除了一件事，一切都很好。
如果我进入编辑模式并从表视图中删除一个项目，该项目将从表视图和数组中删除——这部分似乎工作正常。但是，删除项目后，如果我点击栏按钮项目添加新任务，我会遇到问题。
我的 NSLogs 告诉我新项目已添加到数组中，但是当我返回表视图时，显示的是已删除项目而不是新项目。表格视图似乎正在重用出队的单元格（不确定）。
我究竟做错了什么？
CLCheckListViewController.m
#import "CLCheckListViewController.h"
#import "CLTaskFactory.h"
#import "CLTaskStore.h"
#import "CLAddTaskViewController.h"
@implementation CLCheckListViewController
{
__weak IBOutlet UITableView *checkList;
}
- (id)init
{
self = [super init];
if (self) {
// add five sample tasks
CLTaskFactory *task1 = [[CLTaskFactory alloc] init];
[task1 setTaskName:@"Task 1"];
[task1 setDidComplete:NO];
[[CLTaskStore sharedStore] addTask:task1];
CLTaskFactory *task2 = [[CLTaskFactory alloc] init];
[task2 setTaskName:@"Task 2"];
[task2 setDidComplete:NO];
[[CLTaskStore sharedStore] addTask:task2];
CLTaskFactory *task3 = [[CLTaskFactory alloc] init];
[task3 setTaskName:@"Task 3"];
[task3 setDidComplete:NO];
[[CLTaskStore sharedStore] addTask:task3];
CLTaskFactory *task4 = [[CLTaskFactory alloc] init];
[task4 setTaskName:@"Task 4"];
[task4 setDidComplete:NO];
[[CLTaskStore sharedStore] addTask:task4];
CLTaskFactory *task5 = [[CLTaskFactory alloc] init];
[task5 setTaskName:@"Task 5"];
[task5 setDidComplete:NO];
[[CLTaskStore sharedStore] addTask:task5];
}
return self;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[checkList reloadData];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// create edit button
[[self navigationItem] setLeftBarButtonItem:[self editButtonItem]];
// create title
[[self navigationItem] setTitle:@"Checklist"];
// create add guest button
UIBarButtonItem *bbi = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(pushAddTask)];
[[self navigationItem] setRightBarButtonItem:bbi];
}
- (void)pushAddTask
{
CLAddTaskViewController *advk = [[CLAddTaskViewController alloc] init];
[[self navigationController] pushViewController:advk animated:YES];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [[[CLTaskStore sharedStore] allTasks] count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [checkList dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
// put the tasks into the cell
[[cell textLabel] setText:[NSString stringWithFormat:@"%@", [[[CLTaskStore sharedStore] allTasks] objectAtIndex:[indexPath row]]]];
// put the checkbox into the cell's accessory view
UIButton *checkBox = [UIButton buttonWithType:UIButtonTypeCustom];
checkBox = [UIButton buttonWithType:UIButtonTypeCustom];
[checkBox setImage:[UIImage imageNamed:@"checkbox.png"] forState:UIControlStateNormal];
[checkBox setImage:[UIImage imageNamed:@"checkbox-checked.png"] forState:UIControlStateSelected];
checkBox.frame = CGRectMake(0, 0, 30, 30);
checkBox.userInteractionEnabled = YES;
[checkBox addTarget:self action:@selector(didCheckTask:) forControlEvents:UIControlEventTouchDown];
cell.accessoryView = checkBox;
}
return cell;
}
- (void)didCheckTask:(UIButton *)button
{
CGPoint hitPoint = [button convertPoint:CGPointZero toView:checkList];
hitIndex = [checkList indexPathForRowAtPoint:hitPoint];
task = [[[CLTaskStore sharedStore] allTasks] objectAtIndex:[hitIndex row]];
if (task.didComplete) {
task.didComplete = NO;
} else {
task.didComplete = YES;
}
NSInteger taskCount = [[[CLTaskStore sharedStore] allTasks] count];
for (int i = 0; i < taskCount; i++) {
NSLog(@"%@, status: %@", [[[CLTaskStore sharedStore] allTasks] objectAtIndex:i], [[[[CLTaskStore sharedStore] allTasks] objectAtIndex:i] didComplete]?@"YES":@"NO");
}
// toggle checkbox
button.selected = !button.selected;
}
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing:editing animated:animated];
// set editing mode
if (editing) {
self.navigationItem.title = @"Edit Checklist";
[checkList setEditing:YES];
} else {
self.navigationItem.title = @"Checklist";
[checkList setEditing:NO];
}
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath
{
// remove task
if (editingStyle == UITableViewCellEditingStyleDelete) {
// remove task from CLTaskStore
task = [[[CLTaskStore sharedStore] allTasks] objectAtIndex:[indexPath row]];
[[CLTaskStore sharedStore] removeTask:task];
// remove guest from table view
[checkList deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
// reload table view
//[checkList reloadData];
}
}
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
[[CLTaskStore sharedStore] moveTaskAtIndex:[sourceIndexPath row] toIndex:[destinationIndexPath row]];
}
@end
CLAddTaskViewController.m
#import "CLAddTaskViewController.h"
#import "CLTaskFactory.h"
#import "CLTaskStore.h"
@implementation CLAddTaskViewController
- (void)viewDidLoad
{
[[self navigationItem] setTitle:@"Add Task"];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
// clear first responder
[[self view] endEditing:YES];
// create new task
CLTaskFactory *newTask = [[CLTaskFactory alloc] init];
[newTask setTaskName:[newTaskName text]];
// add new guest to RCGuestStore
[[CLTaskStore sharedStore] addTask:newTask];
}
@end
CLAddTaskFactory.m
#import "CLTaskFactory.h"
@implementation CLTaskFactory
@synthesize taskName;
- (void)setDidComplete:(BOOL)dc
{
didComplete = dc;
}
- (BOOL)didComplete
{
return didComplete;
}
- (NSString *)description
{
// override the description
NSString *descriptionString = [[NSString alloc] initWithFormat:@"%@", taskName];
return descriptionString;
}
@end
CLAddTaskStore.m
#import "CLTaskStore.h"
#import "CLTaskFactory.h"
#import "CLCheckListViewController.h"
@implementation CLTaskStore
+ (id)allocWithZone:(NSZone *)zone
{
return [self sharedStore];
}
+ (CLTaskStore *)sharedStore
{
static CLTaskStore *sharedStore = nil;
if (!sharedStore) {
sharedStore = [[super allocWithZone:nil] init];
}
return sharedStore;
}
- (id)init
{
self = [super init];
if (self) {
allTasks = [[NSMutableArray alloc] init];
}
return self;
}
- (NSMutableArray *)allTasks
{
return allTasks;
}
- (void)addTask:(CLTaskFactory *)task
{
[allTasks addObject:task];
NSLog(@"Task added: %@", task);
}
- (void)removeTask:(CLTaskFactory *)task
{
// remove the item for the deleted row from the store
[allTasks removeObjectIdenticalTo:task];
NSInteger taskCount = [allTasks count];
NSLog(@"Removed: %@, there are now %d remaining tasks, they are:", task, taskCount);
for (int i = 0; i < taskCount; i++) {
NSLog(@"%@, status: %@", [[[CLTaskStore sharedStore] allTasks] objectAtIndex:i], [[[[CLTaskStore sharedStore] allTasks] objectAtIndex:i] didComplete]?@"YES":@"NO");
}
}
- (void)moveTaskAtIndex:(int)from toIndex:(int)to
{
if (from == to) {
return;
}
CLTaskFactory *task = [allTasks objectAtIndex:from];
[allTasks removeObjectAtIndex:from];
[allTasks insertObject:task atIndex:to];
}
@end
谢谢你的帮助！