默认图片是空的
有提示文字“You can sync photos and videos onto your iPad Simulator using iTunes.”
结果有人发现，其实这是坑爹的文字模板”You can sync photos and videos onto your {DEVICE_NAME} using iTunes.”，｛DEVICE_NAME｝会被[[UIDevice currentDevice] model]替换，如果是在真机上测试，itunes当然是可以同步图片的，但是模拟器上无法用itunes。
解决办法：
首先打开模拟器，并进入photo
然后用safari浏览到一张图片，然后拖拽图片到iphone模拟器
模拟器会用模拟器的safari打开图片
然后在图片上长按鼠标，弹出对话框，选择保存，这时再回到phot里就可以看到图片了。
枚举, for … in 语法
1 | for ( Type newVariable in expression ) { statements } |
或
1 2 | Type existingItem; for ( existingItem in expression ) { statements } |
使用for…in语法的expression必须实现 NSFastEnumeration协议，NSArray, NSDictionary, NSSet, NSDictionary 等 实现了此协议。
例如
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | NSArray *array = [NSArray arrayWithObjects: @"One", @"Two", @"Three", @"Four", nil]; for (NSString *element in array) { NSLog(@"element: %@", element); } NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys: @"quattuor", @"four", @"quinque", @"five", @"sex", @"six", nil]; NSString *key; for (key in dictionary) { NSLog(@"English: %@, Latin: %@", key, [dictionary objectForKey:key]); } |
也可以使用NSEnumerator对象进行遍历
1 2 3 4 5 6 7 8 9 10 11 12 | NSArray *array = [NSArray arrayWithObjects: @"One", @"Two", @"Three", @"Four", nil]; NSEnumerator *enumerator = [array reverseObjectEnumerator]; for (NSString *element in enumerator) { if ([element isEqualToString:@"Three"]) { break; } } NSString *next = [enumerator nextObject]; // next = "Two" |
路径问题
sqlite文件不能作为resource bundle存在在项目中，否则会被每次覆盖
最好存储在Library或Documents
获得Documents路径
1 2 3 4 5 6 |
检查documents路径下是否有db文件，如果没有，从resource bundle路径下copy
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Override point for customization after application launch. NSString * dbPath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:@"user.db"]; NSLog(@"dbPath=%@", dbPath); NSFileManager * fm = [NSFileManager defaultManager]; if(![fm fileExistsAtPath:dbPath]) { NSString * localPath = [[NSBundle mainBundle] pathForResource:@"user" ofType:@"db"]; if(localPath) [fm copyItemAtPath:localPath toPath:dbPath error:nil]; } self.window.rootViewController = self.viewController; self.viewController.dbPath = dbPath; [self.window makeKeyAndVisible]; return YES; } |
从 Apple 菜单中，选取系统偏好设置…。
从显示菜单中，选取帐户。
点按锁图标并使用管理员帐户进行鉴定。
点按“登录选项…”。
点按右下部的“编辑…”或“加入…”按钮。
点按“打开目录实用工具…”按钮。
点按“目录实用工具”窗口中的锁图标。
输入管理员帐户名称和密码，然后点按“好”。
从编辑菜单中选取启用 Root 用户。
在“密码”和“验证”字段中输入您想要使用的 root 密码，然后点按“好”。
KeyBoard Notifications(通过系统通知获得键盘的位置大小等)
UIKeyboardWillShowNotification
UIKeyboardDidShowNotification
UIKeyboardWillHideNotification
UIKeyboardDidHideNotification
可以通过UIKeyboardFrameBeginUserInfoKey 和 UIKeyboardFrameEndUserInfoKey，从userInfo的字典数据结构中获得键盘size和坐标的信息
应当每次处理这些信息，因为键盘所占用屏幕空间并不每次都一样（根据键盘的类型和定义）
显示键盘
一般来说，当用户选择可输入文本的视图时会自动弹出系统键盘，也可以通过编程方式，调出键盘（becomeFirstResponder相当于获得焦点，resignFirstResponder相当于失去焦点）
1 | [textfield becomeFirstResponder]; |
隐藏键盘
和显示键盘不同，键盘不会自动隐藏，而需要开发者自行关闭
1 | [myTextField resignFirstResponder]; |
当键盘弹出时挡住要输入内容位置时的处理
1. 获得键盘的位置和Size
2. 计算需要调整的高度
3. 将UIScrollView滚动到相应位置
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | // 在你的ViewController 某处调用这个方法注册notification方法 - (void)registerForKeyboardNotifications { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:) name:UIKeyboardDidShowNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillBeHidden:) name:UIKeyboardWillHideNotification object:nil]; } // Called when the UIKeyboardDidShowNotification is sent. - (void)keyboardWasShown:(NSNotification*)aNotification { NSDictionary* info = [aNotification userInfo]; CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size; UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0); scrollView.contentInset = contentInsets; scrollView.scrollIndicatorInsets = contentInsets; // If active text field is hidden by keyboard, scroll it so it's visible // Your application might not need or want this behavior. CGRect aRect = self.view.frame; aRect.size.height -= kbSize.height; if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) { CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y-kbSize.height); [scrollView setContentOffset:scrollPoint animated:YES]; } } // Called when the UIKeyboardWillHideNotification is sent - (void)keyboardWillBeHidden:(NSNotification*)aNotification { UIEdgeInsets contentInsets = UIEdgeInsetsZero; scrollView.contentInset = contentInsets; scrollView.scrollIndicatorInsets = contentInsets; } |
相关源码
KeyboardAccessory
read:
Layer Geometry and Transforms
sample code download:
Touches
SimpleGestureRecognizers
例子：UserDefaultsDemo
CoreFoundation
平行于Foundation，基础类都有对应的类，Toll-Free Bridging = 基础数据类型和NS类的转换是没有损耗的
1 2 3 4 5 6 7 | CFArrayRef array = ABAddressBookCopyPeopleWithName(...); NSLog(@“%d”, [(NSArray *)array count]); NSMutableArray *mutableArray = [(NSArray *)array mutableCopy]; [mutableArray release]; if (array) { CFRelease(array); } |
CoreFoundation使用NULL而不是nil
1 2 3 4 5 | CFStringRef string = CreateSomeCFString...; if (string != NULL) { DoSomethingWith(string); CFRelease(string); } |
1 2 3 |
ABAddressBookRef获得联系人名单
1 2 | ABAddressBookRef ab = ABAddressBookCreate(); CFArrayRef people = ABAddressBookCopyPeopleWithName(ab, name); |
ABRecordRef
包括属性
■ First and last name
■ Image
■ Phone numbers, emails, etc…
单一属性，包括：
First Name, last name, birthday, etc…
get使用ABRecordCopyValue(…)方法
1 2 | CFStringRef first = ABRecordCopyValue(person, kABPersonFirstNameProperty); |
set使用ABRecordSetValue(…)方法
1 2 | CFDateRef date = CFDateCreate(…); ABRecordSetValue(person, kABPersonBirthdayProperty, date, &error); |
多重属性（ABMultiValueRef），包括：
Phones, emails, URLs, etc…
类型用ABMultiValueRef表示，label/value
获得count
1 | CFIndex count = ABMultiValueGetCount(multiValue); |
获得value
1 | CFTypeRef value = ABMultiValueCopyValueAtIndex(mv, index); |
获得label
1 | CFStringRef label = ABMultiValueCopyLabelAtIndex(mv, index); |
获得identifier
1 | CFIndex identifier = ABMultiValueGetIdentifierAtIndex(mv, index); |
更新流程：
• 获取多重属性控制
• 增加值
• 将值赋予联系人
• 保存通讯录
1 2 3 4 5 | ABMultiValueRef urls = ABRecordCopyValue(person, kABPersonURLProperty); ABMutableMultiValueRef urlCopy = ABMultiValueCreateMutableCopy(urls); ABMultiValueAddValueAndLabel(urlCopy, "the url", "social", NULL); ABRecordSetValue(person, urlCopy, kABPersonURLProperty); ABAddressBookSave(ab, &err); |
排序
可使用内置的ABPersonGetSortOrdering，ABPersonComparePeopleByName,作为排序方法
1 2 3 4 5 | CFMutableArrayRef people = // obtain an array of people CFRange fullRange = CFRangeMake(0, CFArrayGetCount(people)); ABPersonSortOrdering sortOrdering = ABPersonGetSortOrdering(); CFArraySortValues(people, fullRange, ABPersonComparePeopleByName, (void*)sortOrdering); |
或者使用objc的风格（下例中people是NSMutableArray）
1 | [people sortUsingFunction:ABPersonComparePeopleByName context:(void*)sortOrdering]; |
获得联系人名字
1 2 3 | ABRecordRef person = // get a person CFStringRef name = ABRecordCopyCompositeName(person); // do something clever with that person’s name |
或
1 2 3 |
ABPersonViewController属性
■ displayedPerson
■ displayedProperties
■ allowsEditing
ABUnknownPersonViewController属性
■ displayedPerson
■ allowsAddingToAddressBook
■ delegate
ABPeoplePickerNavigationController
1 2 3 4 5 6 | ABPeoplePickerNavigationController *ppnc = [[ABPeoplePickerNavigationController alloc] init]; ppnc.peoplePickerDelegate = self; ppnc.displayedProperties = [NSArray arrayWithObject:[NSNumber numberWithInt:kABPersonEmailProperty]]; ppnc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:ppnc animated:YES]; [ppnc release]; |
1 2 3 4 5 6 7 8 | // cancel选择 - (void)peoplePickerNavigationControllerDidCancel:(ABPeoplePickerNavigationController *)peoplePicker // 当选择了通讯录的的某个联络人 - (BOOL)peoplePickerNavigationController:(ABPeoplePickerNavigationController *)peoplePicker shouldContinueAfterSelectingPerson:(ABRecordRef)person // 当选择了通讯录的某个联络人的某个属性 - (BOOL)peoplePickerNavigationController:(ABPeoplePickerNavigationController *)peoplePicker shouldContinueAfterSelectingPerson:(ABRecordRef)person property:(ABPropertyID)property identifier:(ABMultiValueIdentifier)identifier |