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