object c基础， 基本类型(NSString,char*NSDate,NSData)，集合NSArray,NSMutableArray,NSDictionary,NSMutableDictionary,NSSet,NSMutableSet

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1）。object c 基本类型

ID：指向OC对象的指针；

CLASS；

SEL：是OC来定义方法的关键字，你可以把他当做一个函数指针来使用；

BOOL：YES，NO；TRUE，FLASE；

空值处理不当是引起程序错误的重要原因。

nil:给对象赋值

NULL：给指针赋值

NSNULL: 用于集合操作；

2）常量的声明和预处理宏

常量的声明1

#define kdetailkey @"detail text"

#define dd 30.0

#define cc pi*3/180.0

常量的声明2

typedef enum

{

aa=100,

bb,

cc ，

}TagSystemViews ;

常量的声明3

静态常量声明：static NSString *lc=@"test";

预处理宏

预处理宏声明：

#define network 1

#define NSLog()

3).#import包含头文件

4）＃pragram mark分隔代码块

#pragram mark -

#pragram mark network api

5) 内存管理retain,release,引用计数进行自动内存管理；在alloc,retain,copy 的时候对象引用计数增加一，在release时减一,当引用计数为0时，对象的内存就被回收，占用内存释放。

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

// create two objects my MyClass.

SomeClass *object = [[SomeClass alloc] init];

NSLog(@"1,object retain count is : %d",[object retainCount]); // counter is 1

[object retain]; // increment the count, now count is 2

NSLog(@"2,object retain count is : %d",[object retainCount]);

[object release]; // decrement the count, now count is 1

NSLog(@"3,object retain count is : %d",[object retainCount]);

object = nil; // set to nil, now count is 0, now object will deallocate.

NSLog(@"4,object retain count is : %d",[object retainCount]);

NSLog(@"5,object: %@",object);

[pool release];

return 0;

6>字符串操作NSString

私有字符串常量：static NSString *const k=@"myconstant";

公有字符串常量：.h 定义：extern NSString *const k；/ #define NSString *const k;

.m 实现：k=@"info.png";

获取子字符串： rangOfString 获取小字符串在大字符串中的长度范围；

substringToIndex：i 获取开始到i长度的子字符长度；

substringFromIndex：i 获取i开始到末尾的子字符长度；

substringWithRange：i，J ，获取i开始到J的子字符长度；

NSString *filename=@"config.ini";

NSString *path=@"users/dev/desktop/config.ini";

NSRange iStart=[path rangeOfString:filename];

NSRange iStart2=[path rangeOfString:filename options:NSCaseInsensitiveSearch];

if (iStart.length>0) {

NSString *substr=[path substringToIndex:iStart.location-1];

NSString *ex=[path substringFromIndex:iStart.location+1];

合格，格式化字符串

stringWithFormat

NSString *re=[NSString stringWithFormat:@"id is %d name is %@,id,name];

NSMutableString *re=[[NSMutableString alloc] init]; //stingbuffer.app();

[re appendString:string1];

[re appendString:string2];

分隔字符串

NSSting *a=@"dog#cat";

NSArray *b=[a componentsSeparatedByString:@"#"];

获取程序运行时目录

安行读取文件

NSstring *temp;

NSArray *readline=[[NSString stringWithContentsOfFile:@"tests.txt"] componentsSeparatedByString:@"\"];

NSEnumerator *nse=[readline objectEnumerator];

while(temp=[nse nextObject])

{

NSLog(@"%@",temp);

}

NSString char*之间的转换

NSString --> char*:

NSString *ban=@"test a string";

char *pre=[ban cStringUsingEncoding:NSASCIIStingEncoding];

char * -->NSString

char encode_buf[1024];

NSString *enstr=[[NSString alloc] initWithCString:(const char*) encode_buf:NSASCIIStringEncoding];

字符串比较

1）判断是否为空；

if([strobject length] >0)

{

//do something

}

if([strobject isEqualToString:@"some string"])

//do something

7 处理数值对象(NSNumber-->int;CGFloat,NSDecimalNuber])

NSNumber -->int

NSNumber *numobj=[NSNumber numberWithInt:2];

NSInteger myint=[numobj integerValue];

int a=[myint intValue];

8 处理日期时间NSDate

获取当前时间：

NSDate * dateToDay=[NSDate date];

NSDateFormatter *df=[[NSDateFormatter alloc] init];

[df setDateFormat:@yyyy-mm-dd hh:mm:ss"];

NSLocale *locale=[[NSLocale alloc] initWithLocaleIdentifiler:@"en_US"];

[df setLocale:locale];

从字符串生成日期对象：

NSString *mydateString=@"2012-07-13 10:20:00";

NSDate *mydate=[df dateFromString:mydateString];

日期比较：

switch([dateToDay compare:mydate])

{

case NSOrderedSame:

NSLog(@"these dates are the same");

break;

case NSOrderedAscending:

NSLog(@"dateToDay is earlier than mydate");

break;

case NSOrderedDescending:

NSLog(@"mydate is earlier than dateToDay");

break;

default:

NSLog(@"bad time. invalid enum value returned.");

break;

demo:


9 NSData 处理

NSData --> NSString

NSMutableData *data; //NSData *data;

NSString *tmpdata=[[NSString alloc] init WithData:data encoding:NSACIIStringEncoding];

NSLog(@"[***] DATA:%@",tmpdata);

NSSting --> NSData

NSString * str=@"test string";

NSData *data=[str dataUsingEncoding:NSUTF8StringEncoding];

//demo:

void NSDatatTest(){

//NSData 转换为NSString

NSMutableData *data = nil;

NSString *tmpdata = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];

NSLog(@"[***] DATA:%@",tmpdata);

[tmpdata release];

//NSString 转换为 NSData

NSString* str= @"teststring";

NSData* tdata=[str dataUsingEncoding:NSUTF8StringEncoding];

NSLog(@"[***] tdata:%@",tdata);

}

int main(int argc, char *argv[]) {

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

NSDatatTest();

[pool release];

return 0;

}

10 集合操作:包含，比较，循环，获取，删除，复制，排序，过粒

NSArray,NSDictionary,NSSet及动态集合

将多个对象装入数组，数组的最后一个元素必须是nil;

NSArray *arry=[NSArray arrayWithObjects:@"hennry",@"alex",nil];

NSMutableArray *arry=[[NSMutable alloc] arrayWithCapacity:3];

NSArray *newarray=[NSArray arrayWithArray:array];

数组操作 :containsObject:(id)anObject

NSUintegerCount

lastObject

objectAtIndex:(NSUInteger)index

NSMutableArray *arry=[NSMutable arry];

[arry addObject:[NSColor blackColor]];

NSSet:不要求顺次，要求唯一性，用集合NSSet;交集，重复

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