Note_Master-Detail Application(iOS template)_05_ YJYMasterViewController.m
// YJYMasterViewController.m
#import "YJYMasterViewController.h"
#import "YJYDetailViewController.h"
/*
@interface：接口，提供类的公共描述，接口里面包含了使用该类的所需信息，编译此部分后，就能够使用该的对象及调用类方法。
@implementation：实现，告诉编译器如何让该类工作，实现了接口中声明的方法。
代码分为接口和实现两部分，
接口部分包含：@interface指令、公共struct定义、enum常量、@defines和extern全局变量等。
实现部分包含：@implementation指令、全局变量的定义、私有struct等。
＃import：导入头文件：头文件包含元素声明（如，结构体、符号常量、函数原型等），#import同c语言中的#include类似，它们的区别在于，在c语言中，通常使用#ifdef命令来避免一个头文件包含另一个文件，而#import可保证头文件只被包含一次。
带尖括号语句用来导入系统头文件（只读），带引号的语句用来导入项目本地头文件（可读）。
*/
@interface YJYMasterViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end
@implementation YJYMasterViewController
/*
当.nib文件被加载的时候，会发送一个awakeFromNib的消息到.nib文件中的每个对象，每个对象都可以定义自己的 awakeFromNib函数来响应这个消息，
执行一些必要的操作。也就是说通过nib文件创建view对象是执行awakeFromNib
*/
- (void)awakeFromNib
{
self.clearsSelectionOnViewWillAppear = NO;
self.contentSizeForViewInPopover = CGSizeMake(320.0, 600.0);
[superawakeFromNib];
}
//当view对象被加载到内存是就会执行viewDidLoad，所以不管通过nib文件还是代码的方式创建对象都会执行viewDidLoad
- (void)viewDidLoad
{//释放视图资源
NSLog(@"viewDidLoad() begin...");
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItemalloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAddtarget:selfaction:@selector(insertNewObject:)];
self.navigationItem.rightBarButtonItem = addButton;
self.detailViewController = (YJYDetailViewController *)[[self.splitViewController.viewControllerslastObject] topViewController];
NSLog(@"viewDidLoad() over...");
}
- (void)didReceiveMemoryWarning
{
NSLog(@"didReceiveMemoryWarning() begin...over");
[superdidReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)insertNewObject:(id)sender
{
NSLog(@"insertNewObject() begin...");
NSManagedObjectContext *context = [self.fetchedResultsControllermanagedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsControllerfetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescriptioninsertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
[newManagedObject setValue:[NSDate date] forKey:@"timeStamp"];
// Save the context.
NSError *error = nil;
if (![context save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
NSLog(@"insertNewObject() over...");
}
#pragma mark - Table View
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
NSLog(@"numberOfSectionsInTableView being...over");
return [[self.fetchedResultsControllersections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(@"tableView numberOfRowsInSection() beging...");
id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
NSLog(@"tableView numberOfRowsInSection() over...");
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"tableView cellForRowAtIndexPath() beging...");
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"forIndexPath:indexPath];
[self configureCell:cell atIndexPath:indexPath];
NSLog(@"tableView cellForRowAtIndexPath() over...");
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{//该方法控制master区的可编辑（删除）操作
// 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) {
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
[context deleteObject:[self.fetchedResultsController objectAtIndexPath:indexPath]];
NSError *error = nil;
if (![context save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
// The table view should not be re-orderable.
returnYES;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];
self.detailViewController.detailItem = object;
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController != nil) {
return_fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescriptionentityForName:@"Event"inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timeStamp" ascending:NO];
NSArray *sortDescriptors = @[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsControlleralloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContextsectionNameKeyPath:nilcacheName:@"Master"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsControllerperformFetch:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return_fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableViewbeginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type) {
caseNSFetchedResultsChangeInsert:
[self.tableViewinsertSections:[NSIndexSetindexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
caseNSFetchedResultsChangeDelete:
[self.tableViewdeleteSections:[NSIndexSetindexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type) {
caseNSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:@[newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
caseNSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
caseNSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
caseNSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:@[indexPath]withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:@[newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableViewendUpdates];
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
// In the simplest, most efficient, case, reload the table view.
[self.tableView reloadData];
}
*/
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"configureCell atIndexPath() begin...");
NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[object valueForKey:@"timeStamp"] description];
NSLog(@"configureCell atIndexPath() over...");
}
@end
