//代码片段:(不使用故事板时 用应用类手动创建初始界面)
-(BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}
NSString *bundlePathName = [[NSBundle mainBundle] resourcePath];
NSString *filePathName = [NSString stringWithFormat:@"%@/textfile.text",bundlePathName];
NSError *fileError;
NSString *textFileContents = [NSString stringWithContentsOfFile:filePathName encoding:NSASCIIStringEncoding error:&fileError];
if(fileError.code == 0)
NSLog(@" textFile.text contents : %@",textFileContents);
else
NSLog(@"error(%ld):%@ ",fileError.code,fileError.description);
ios可以从包资源目录中读取文本文件,但不能向包资源目录中写入任何文件,只能写到文档目录中。
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) lastObject];
NSString *filePathName = [NSString sreingWithFormat:"%@/textfile.txt",documentDirectory];
NSError *fileError;
NSString *textFileContents = @"Content generated from ios app.";
[textFileContents writeToFile:filePathName atomically:YES encoding:NSStringEncodingConversionAllowLossy error:&fileError];
if(fileError.code == 0)
NSLog(@"textfile.text was writtrn successfully with these contents:%@",textFileContents);
else
NSLog(@"error(%d): %@",fileError.code,fileError.desprition);
比较使用NSRange定义起点与长度的字串
NSString *alphabet = @"ABCDEFGHIJKLMON";
NSrange range = NSMakeRange(2,3);
BOOL lettersInRange = [[alphabet substringWithRange:range] isEqualToString:@"CDE"];
使用NSMutableString
向可变字符串任意位置插入字符
[myString insertString:@"abcdefg, " atIndex:0]
删除NSRange范围指定的字符
NSRange range = NSMakeRange(9,3);
myString deleteCharactersInRange:range];
将NSRange指定范围内某个字符替换为不同的字符
NSRange rangeOfString = [myString rangeOfString:myString];
myString replaceOccurrencesOfString:@"," withString:@"|" options:NSCaseInsensitiveSearch range:rangeOfString];
替换NSrange指定范围的字符
NSRange rangeToReplace = NSMakeRange(0,4);
myString replaceCharactersInRange:rangeToReplace withString:@"MORE"];
类似浮点数这样的原生类型
folat fNumber = 12;
NSString *floatToString = [NSString stringWithFormat:@"%f",fNumber];
如果是NSNumber对象
NSNumber *number = [NSNumber numberWithFloat:30];
NSString *numberToString = [number stringValue];
转换为原生类型
NSString *aFloatValue = @"12.50";
float f = [aFloatValues floatValue];
转换为NSNumber对象
NSNumber *aFloatNumber = [NSNumber numberWithFloat:[aFloatValue floatValue]];
以货币的形式将其显示出来
NSNumber *numberToFormat = [NSNumber numberWithFloat:9.99];
NSNumberFormatter *numberFormatter = [[NSNumberFormat alloc] init];
numberFormatter.numberStyle = NSNumberFormatterCurrencyStyle;
NSLog(@"Formatted for currency :%@",[numberFormatter stringFromNumber:numberToFormat]);
使用指定对象初始化数组:
NSArray *listOfLetters = [NSArray arrayWithObjects:@"A",@"B",@"C",nil];
其他初始化方法:
-(id)initWithContentsOfFile:(NSString *)path;
-(id)initWithContentsOfURL:(NSURL *)url;
objectAtIndex: 获取数组中位于摸个整数位置的对象引用
lastObject 获取数组中最后一个对象的引用
indexOfObject: 获取对象在数组中的位置
makeObjectsPerformSelector:withObject 可以传递希望每个对象都执行的方法名和一个参数
[listofObjects makeObjectsPerformSelector:@selector(appendString:) withObject:@"-MORE"];
向数组中每个可变字符串发送 appendString:消息
使用enumerateObjectsUsingBlock: (Effective objective c中提过)
[listOfobjects enumerateObjectsUsingBlock:^(id obj,NSUInteger idx,BOOL *stop){
NSLog(@" object(%lu) 's description is %@",idx,[obj description]);
}];
使用NSSortDescription
使用NSSortDescriptor对象为每个Persion属性提供排序描述符,然后放入数组中
NSSortDescription *sd1 = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES];
NSSortDescription *sd2 = [NSSortDescriptor sortDescriptorWithKey:@"lastName" ascending:YES];
NSSortDescription *sd3 = [NSSortDescriptor sortDescriptorWithKey:@"firstName" ascending:YES];
NSArray *sdArray1 = [NSArray arrayWithObject:sd1,sd2,sd3,nil];
获得排序好的数组
NSArray *sortArray1 = [persionList sortedArrayUsingDescriptors:sdArray1];
使用NSPredicate对象。
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"age > 30"];
NSArray *arraySubset = [listOfObjects filteredArrayUsingPredicate:predicate];
for-each遍历
for (NSString *s in [dictionary allValues]){
NSLog(@"value: %@ ",s);
}
for (NSString *s in [dictionary allkeys]){
NSLog(@"key: %@",s)
}
使用enumerateKeysAndObjectsUsingBlock:
[dictionary enumeraKeysAndObjectsUsingBlock:^(id key,id obj,BOOL *stop){
NSLog(@”key = %@ and obj = %@”,key,obj);
}];
使用NSSet 与 NSMutableSet
NSSet *set = [NSSet setWithObjects:@"Hello World",@"Bonjour tout le monde",@"Hola Mundo",nil];
其他创建方式
-(id)initWithArray:(NSArray *)array;
NSSet *set1 = [NSSet setWithObjects@"A",@"B",@"C",@"D",@"E",nil];
NSSet *set2 = [NSSet setWithObjects@"D",@"E",@"F",@"G",@"H",nil];
//判断两个集合是否相交
BOOL setsIntersect = [set1 intersectsSet:set2];
//判断某个集合包含饿的对象是否全部位于两一个集合中
BOOL set2IsSubset = [set2 isSubsetofSet:set1];
//判断两个集合是否相等
BOOL set1ISEqualToSet2 = [set1 isEqualToSet:set2];
//判断某个对象是否位于集合中
BOOL set1ContainsD = [set1 containsObject:@"D"];
使用 for-each
for(NSString *s in [set allObjects]){
NSLog(@" value:%@ ",s);
}
使用enumerateObjectsUsingBlock:
[set enumerateObjectsUsingBlock:^(id obj,BOOL *stop){
NSLog(@" obj = @% ",obj);
}];
获得指向应用包得引用
NSString *bundlePath = [[NSBundle mainBundle] bundlePath];
获得其他目录:
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirctory,NSUserDomainMask,YES)lastObject];
//用户生成内容的位置
NSDocumentDirectory
//应用的库目录
NSLibraryDirectory
//缓存文件的目录
NSCachesDirectory
获取文件属性
NSFileManager *fileManager = [NSDileManager defaultManager];
NSString *filePathName = @”/User/shared/textfile.txt”;
NSError *error = nil;
NSDictionary *fileAttributes = [fileManager attributesOfItemAtPath:filePathName error:&error];
if(!error){
NSDate *dateFileCreated = [fileAttributes valueForKey:NSFileCreationDate];
NSString *fileType = [fileAttributes valueForKey:NSFileType];
}
目录常量 | 说明 |
---|---|
NSFileType | 文件类型 |
NSFileSize | 文件大小(字节) |
NSFileModificationDate | 文件上次修改的时间 |
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *sharedDirectory = @"/Users/Shared";
NSerror *error = nil;
NSArray *listOfFiles = [fileManager contentsofDirectoryAtPath:sharedDirectory error:&error];
NSArray *listSubPath = [fileManagersubpathsOfDirectoryAtPath:sharedDirectory error:&error];
操作 | 方法 |
---|---|
新建目录 | createDirectoryAtPath:withIntermediateDirectories:attributes:error: |
移动目录 | moveItemAtPath:toPath:error |
删除目录 | removeItemAtPath:error: |
复制目录 | copyItemAtPath:toPath:error |
BOOL directoryCreated = [fileManager createDirectoryAtPath:newDirectory withIntermediateDirectories:YES attributes:nil error:&error];
BOOL directoryMoved = [fileManager moveItemAtPath:newDirectory toPath:directoryMovedTo error:&error];
BOOL directoryCopied = [fileManager copyItemAtPath:directoryToCopy toPath:directoryToCopyTo error:&error];
操作 | 方法 |
---|---|
新建文件 | createFileAtPath:contents:attributes: |
移动文件 | moveItemAtPath:error |
删除文件 | removeItemAtPath:error: |
复制文件 | copyItemAtPath:toPath:error: |
NSFileManager *fileManager = [NSFileManager defaultManager];
NSURL *url = [NSURL URLWithString:@”http://xxx.xx.jpg“];
NSData *dataObject = [NSData dataWithContentOfURL:url];
NSString *newFile = @”/Users/shared/xx.jpg”;
BOOL fileCreated = [fileManager createFileAtPath:newFile contents:dataObject attributes:nil];
状态 | 方法 |
---|---|
文件是否存在 | fileExistsAtPath: |
文件是否可读 | isReadableFileAtPath: |
文件是否可写 | isWritableFileAtPath:filePathName |
文件是否可执行 | isExcutableFileAtPath: |
文件是否可删除 | isDeletableFileAtPath: |
NSDate *todaysDate = [NSData date];
//使用NSDateComponents
NSDateComponents *dateComponents = [[NSDateComponent alloc]init];
//设置日期属性
dateComponents.year = 2007;
dateComponents.month = 6;
dateComponents.day = 29;
dateComponents.hour = 12;
dateComponents.minute = 01;
dateComponents.second = 31;
//加利福尼亚州
dateComponents.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"PDT"];
//创建NSDate对象
NSDate *iPhoneReleaseDate = [[NSCalendar currentCalendar] dateFromComponents:dateComponents];
操作 | 方法 |
---|---|
判断是否相等 | isEqualToDate: |
判断某个日期是否遭遇另一个日期 | earlierDate: |
判断哪个日期更晚 | laterDate: |
获得两个日期之间相差的秒数 | 使用 timeIntervalSinceDate: 并将第二个日期作为参数 ,或者使用NSDateComponents 、 NSCalendar |
//获得系统日历引用
NSCalendar *systemCalendar = [NSCalendar currentCalendar];
//通过对NSCalendar常量进行安慰或运算来制定采用的时间单位
Unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
//返回NSDateComponents对象
NSDateComponents *dateComparisonComponents = [systemCalendar components:unitFlags fromDate:iPhoneReleaseDate toDate:todaysDate options:NSWrapCalendarComponents];
NSString *dateString = @"02/14/2012";
NSDateFormatter *df = [[NSDateFormatter alloc]init];
df.dateFormate = @"MM/dd/yyyy";
NSDate *valentinesDay = [df dateFromString:dateString];
df.dateFormate = @"EEEE, MMMM d" ;
[sd stringFromDate:valentiesDay];
//结果是 Tuesday, February 14
//获得情人节前一周的时间
NSDateComponents *weekBeforeDateComponents = [[NSDateComponents alloc]init];
weekBeforeDateComponents.week = -1;
NSDate *vDayShoppingDay = [[NScalendar currentCalendar] dateByAddingComponents:weekBeforeDateComponents toDate:valentiesDay options:0];
//使用 NSData和NSURL
NSURL *remoteTextFileURL = [NSURL URLWithString:@"http://xxx.xxx.xxx/xxx.text"];
NSData *remoteTextFileData = [NSData dataWithContentsOfURL:remoteTextFileURL];
[remoteTextFileData writeToFile:@"/User/shared/xxx.txt" atomically:YES];
//使用NSXMLParserDelegate
//在读到每个新的XML元素时执行一次
parser:didStartElement:namespaceURI:qualifiedName:attributes
//在每次遇到文件中的XML元素的数据时执行
-(void)parse:(NSXMLParse*)parse foundCharacters:(NSString*)string
//JSON : {"Person":"Mattew J. Campbell","Gender":"Male"}
NSError *error;
NSDictionary *bitlyJson = [NSJSonSericalization JSONObjectWithData:responseData options:0 error:&error];
if(!error){
NSString *Person = [bitlyJson objectForKey:@"Person"];
}
//获取对象中的name属性
id temp;
temp = [workProject01 valueForKey:@"name"] ;
//通过kvc设置属性值
[workProject01 setValue:@"my Pet Project" forKey:@"name"];
//通常通过点符号查看属性
id temp;
temp = workProject01.persionInCharge.name;
//使用键路径
temp = [workProject01 valuesForKeyPath:@"personInCharge.name"];
//使用键路径设置属性
[workProject01 setValue:@"Mary steinbeck" forKeyPath:@"personInCharge.name"];
使用@count、@sum、@avg、@min、@max与@distinctUnionOfObject获得对象图数组中的聚合信息
//listOfTasks 是Task对象的数组。每个Task对象都有名为priority的int类型属性
//获得priority值的总数
id sum = [workProject01 valuesForKeyPath:@"[email protected]"];
//get the averageof all the priority values
id average = [workProject01 valuesForKeyPath:@"[email protected]"];
//Get the minumum of all the priority values
id min = [workProject01 valuesForKeyPath:@"[email protected]"];
//Get the maximum of the priority values
id max = [workProject01 valuesForKeyPath:@"[email protected]"];
//获取不重复的对象列表
id listOfWorkers = [workProject-1 valueForKeyPath:@"[email protected]"];
使用NSObject内置方法来探查类来知晓某个对象是否是某个类的实例,对象是否会响应选择器,以及对象是否等于另一个对象。
//使用respondsToSelector查看是否能响应消息
//查看projectManager是否有writeReportToLog方法
id projectManager = [workProject01 valueForKey:@"personInCharge"];
BOOL doesItRespond = [projectManager respondsToSelector@selector(writeReportToLog)] ;
//使用isKindOfClass判断某个对象是否是某个类或子类的实例
BOOL isItAKindOgClass = [consulter isKindOfClass:[Worker class]];
isItKindOfClass = [projectManager isKindOfClass:[Worker class]];
//使用isMemberOfClass盘算某个对象是否是某个类的实例(不包括子类)
BOOL isAnInstanceOfClass = [projectManager isMemberOfClass:[Worker class]];
isAnInstanceOfClass = [consulter isMemberOfClass:[Worker class]];
//判断两个对象引用是否指向相同的对象
BOOL is Equal = [projectManager isEqual:consulter];
使用NSCoding协议中的 encodeWithCoder: 与 initWithCoder
//向Worker.m中的Worker(name,role)实现添加encodeWithCoder 和 initWithCoder
-(void) encodeWithCoder:(NSCoder*)encoder{
[encoder encodeObject:self.name forKey:@"namekey"];
[encoder encodeObject:self.role forKey:@"rolekey"];
}
-(id)initWithCoder:(NSCoder*)decoder{
self.name = [decoder decodeObjecyForKey:@"namekey"];
self.role = [decoder decodeObjectForKey:@"rolekey"];
return self;
}
然后使用NSKeyedArchiver保存或者取出对象
//保存
BOOL dataArchived = [NSKeyArchiver archiveRootObject:workProject01 toFile:@"/Users/Shared/workProject01.dat"] ;
if(dataArchived)
NSLog(@" object graph successfully archived ");
else
NSLog(@" Error attempting to archive object garph ");
//恢复
Project *storedProject = [NSKeyedUnarchiver unarchiveObjectWithFile:@"/Users/Shared/workProject01.dat"];
if(storedProject)
[storedProject writeReportToLog];
else
NSLog(@"Error attempting to retrieve the object graph");