一些常用代码

/*-----字符串常用操作-------*/
NSLog(@"rect1: %@", NSStringFromCGRect(rect1));
//1，字符串拼接
NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];
//2，字符转int
int intString = [newString intValue];
//3，int转字符
NSString *stringInt = [NSString stringWithFormat:@"%d",intString];
//4，字符转float
float floatString = [newStringfloatValue];
//5，float转字符
NSString *stringFloat = [NSStringstringWithFormat:@"%f",intString];

/*-------创建一个数组，并初始化数组为输入值，然后写入-----------*/
NSDictionary *RegisterDic_ = [[NSDictionaryalloc] initWithObjects:                      [NSArrayarrayWithObjects:_userNameTextField.text,_passwordTextField.text,_emailTextField.text, nil] forKeys:          [NSArrayarrayWithObjects:@"username",@"password",@"email",nil]];

NSString * homebrew = @"imperial india pale Ale(ipa)";
//从第25开始，获取三个字符
NSRange range =NSMakeRange(25, 3);
//以下代码等价
//  NSRange range ={25,3};
//对字符串取子串
NSLog(@"beer shortname %@",[homebrew substringWithRange:range]);

//搜索字符串，输出range is{25,3}
NSRange range = [homebrew rangeOfString:@"ipa"];
//判断是否找到字符串
if (range.length]] > 0)
{
NSLog(@"%@",NSStringFromRect(range));
}

在iphone中，除了系统的颜色之外，我们还可以自定义颜色，下面有两种方式：
UIColor *newColor = [[UIColor alloc] initWithRed:(float) green:(float) blue:(float) alpha:(float)];

//alpha：  0.0~1.0

UIColor *tiniColor =

[UIColor colorWithRed:255/255.0 green:175/255.0 blue:64/255.0 alpha:1.0];

修改navigationbar的背景颜色

可以修改navigationbar的tintcolor属性来达到目的，

self.navigationController.navigationBar.tintColor = [UIColor colorWithRed:200/255.0f green:200/255.0f  blue:184/255.0f alpha:1.0f];
/*******************************************************************************************
NSString
*******************************************************************************************/
//一、NSString
/*----------------创建字符串的方法----------------*/
//获取文件路径     NSString *path =[ [NSBundle mainBundle] pathForResource:@"test"ofType:@"png"];
NSFileManager *fm = [NSFileManagerdefaultManager];
if([fm fileExistsAtPath:path])
NSLog(@"yes");
else
NSLog(@"no");

//1、创建常量字符串。
NSString *astring = @"This is a String!";

//2、创建空字符串，给予赋值。

NSString *astring = [[NSString alloc] init];
astring = @"This is a String!";
[astring release];
NSLog(@"astring:%@",astring);

//3、在以上方法中，提升速度:initWithString方法

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
[astring release];

//4、用标准c创建字符串:initWithCString方法

char *Cstring = "This is a String!";
NSString *astring = [[NSString alloc] initWithCString:Cstring];
NSLog(@"astring:%@",astring);
[astring release];

//5、创建格式化字符串:占位符（由一个%加一个字符组成）

int i = 1;
int j = 2;
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];
NSLog(@"astring:%@",astring);
[astring release];

//6、创建临时字符串

NSString *astring;
astring = [NSString stringWithCString:"This is a temporary string"];
NSLog(@"astring:%@",astring);

/*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/

NSString *path = @"astring.text";
NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
NSLog(@"astring:%@",astring);
[astring release];
//打开指定路径上的文本文件，并使用文件内容初始化一个字符串；
/*----------------写字符串到文件:writeToFile方法----------------*/

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
NSString *path = @"astring.text";
[astring writeToFile: path atomically: YES];
[astring release];

/*----------------比较两个字符串----------------*/

//用C比较:strcmp函数

char string1[] = "string!";
char string2[] = "string!";
if(strcmp(string1, string2) = = 0)
{
NSLog(@"1");
}

//isEqualToString方法
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 isEqualToString:astring02];
NSLog(@"result:%d",result);

//compare方法(comparer返回的三种值)
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02] = = NSOrderedSame;
NSLog(@"result:%d",result);
//NSOrderedSame判断两者内容是否相同

NSString *astring01 = @"This is a String!";
NSString *astring02 = @"this is a String!";
BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;
NSLog(@"result:%d",result);
//NSOrderedAscending判断两对象值的大小(按字母顺序进行比较，astring02大于astring01为真)

NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;
NSLog(@"result:%d",result);
//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//不考虑大小写比较字符串1
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;
NSLog(@"result:%d",result);
//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//不考虑大小写比较字符串2
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02
options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;
NSLog(@"result:%d",result);

//NSCaseInsensitiveSearch:不区分大小写比较 NSLiteralSearch:进行完全比较，区分大小写 NSNumericSearch:比较字符串的字符个数，而不是字符值。

/*----------------改变字符串的大小写----------------*/

NSString *string1 = @"A String";
NSString *string2 = @"String";
NSLog(@"string1:%@",[string1 uppercaseString]);//大写
NSLog(@"string2:%@",[string2 lowercaseString]);//小写
NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小

/*----------------在串中搜索子串----------------*/

NSString *string1 = @"This is a string";
NSString *string2 = @"string";
NSRange range = [string1 rangeOfString:string2];
int location = range.location;//位置
int leight = range.length;//長度
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]];
NSLog(@"astring:%@",astring);
[astring release];
/*----------------判断字符串里是否有此字符串----------------*/

NSRange range = [fileName rangeOfString:@"."];
if (range.length==0)

/*----------------抽取子串 ----------------*/

//-substringToIndex: 从字符串的开头一直截取到指定的位置，但不包括该位置的字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
NSLog(@"string2:%@",string2);

//-substringFromIndex: 以指定位置开始（包括指定位置的字符），并包括之后的全部字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringFromIndex:3];
NSLog(@"string2:%@",string2);

//-substringWithRange: //按照所给出的位置，长度，任意地从字符串中截取子串
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
NSLog(@"string2:%@",string2);

//扩展路径
NSString *Path = @"~/NSData.txt";
NSString *absolutePath = [Path stringByExpandingTildeInPath];
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);

//文件扩展名
NSString *Path = @"~/NSData.txt";
NSLog(@"Extension:%@",[Path pathExtension]);

/*******************************************************************************************
NSMutableString
*******************************************************************************************/

/*---------------给字符串分配容量----------------*/
//stringWithCapacity:
NSMutableString *String;
String = [NSMutableString stringWithCapacity:40];
//容量只是建议的最优值，而不是最大值

/*---------------在已有字符串后面添加字符----------------*/

//appendString: and appendFormat:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
//[String1 appendString:@", I will be adding some character"];
[String1 appendFormat:[NSString stringWithFormat:@", I will be adding some character"]];
NSLog(@"String1:%@",String1);
*/

/*--------在已有字符串中按照所给出范围和长度删除字符------*/
/*
//deleteCharactersInRange:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 deleteCharactersInRange:NSMakeRange(0, 5)];
NSLog(@"String1:%@",String1);
//
[string1 deleteCharacterslnRange]:(NSRange *)range;
/*--------在已有字符串后面在所指定的位置中插入给出的字符串------*/

//-insertString: atIndex:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 insertString:@"Hi! " atIndex:0];
NSLog(@"String1:%@",String1);

/*--------将已有的空符串换成其它的字符串------*/

//-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 setString:@"Hello Word!"];
NSLog(@"String1:%@",String1);

/*--------按照所给出的范围，和字符串替换的原有的字符------*/
//-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];
NSLog(@"String1:%@",String1);
//删除原有字符，替换新字符串
/*-------------判断字符串内是否还包含别的字符串(前缀，后缀)-------------*/
//01：检查字符串是否以另一个字符串开头- (BOOL) hasPrefix: (NSString *) aString;
NSString *String1 = @"NSStringInformation.txt";
[String1 hasPrefix:@"NSString"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");
/02：-------------检查方法调用字符串是否以此方法结尾-------------*/
[String1 hasSuffix:@".txt"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");

//03：查找字符串某处是否包含其它字符串 - (NSRange) rangeOfString: (NSString *) aString，这一点前面在串中搜索子串用到过;
/*******************************************************************************************
NSArray
*******************************************************************************************/

/*---------------------------创建数组------------------------------*/
//NSArray *array = [[NSArray alloc] initWithObjects:
@"One",@"Two",@"Three",@"Four",nil];

self.dataArray = array;
[array release];

//- (unsigned) Count;数组所包含对象个数；
NSLog(@"self.dataArray cound:%d",[self.dataArray count]);

//- (id) objectAtIndex: (unsigned int) index;获取指定索引处的对象;
NSLog(@"self.dataArray cound 2:%@",[self.dataArray objectAtIndex:2]);

/*--------------------------从一个数组拷贝数据到另一数组(可变数级)----------------------------*/

//直接复制:
//创建两个空数组
NSArray *array1 = [[NSArray alloc] init];
NSMutableArray *MutableArray = [[NSMutableArray alloc] init];
//创建数组并赋值
NSArray *array = [NSArray arrayWithObjects:
@"a",@"b",@"c",nil];
NSLog(@"array:%@",array);
//把array数组赋给空数组
MutableArray = [NSMutableArray arrayWithArray:array];
NSLog(@"MutableArray:%@",MutableArray);

array1 = [NSArray arrayWithArray:array];
NSLog(@"array1:%@",array1);
//Copy
id obj;
NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

NSLog(@"oldArray:%@",oldArray);
for(int i = 0; i < [oldArray count]; i++)
{
obj = [[oldArray objectAtIndex:i] copy];
[newArray addObject: obj];
}
//
NSLog(@"newArray:%@", newArray);
[newArray release];

//快速枚举

//NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];
NSLog(@"oldArray:%@",oldArray);

for(id obj in oldArray)
{
[newArray addObject: obj];
}
//
NSLog(@"newArray:%@", newArray);
[newArray release];

//Deep copy

//NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];
NSLog(@"oldArray:%@",oldArray);
newArray = (NSMutableArray*)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFPropertyListRef)oldArray, kCFPropertyListMutableContainers);
NSLog(@"newArray:%@", newArray);
[newArray release];

//Copy and sort

//NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"b",@"a",@"e",@"d",@"c",@"f",@"h",@"g",nil];
NSLog(@"oldArray:%@",oldArray);
NSEnumerator *enumerator;
enumerator = [oldArray objectEnumerator];
id obj;
while(obj = [enumerator nextObject])
{
[newArray addObject: obj];
}
[newArray sortUsingSelector:@selector(compare:)];
NSLog(@"newArray:%@", newArray);
[newArray release];

/*---------------------------切分数组------------------------------*/

//从字符串分割到数组－ componentsSeparatedByString:
NSString *string = [[NSString alloc] initWithString:@"One,Two,Three,Four"];
NSLog(@"string:%@",string);
NSArray *array = [string componentsSeparatedByString:@","];
NSLog(@"array:%@",array);
[string release];

//从数组合并元素到字符串- componentsJoinedByString:
NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];
NSString *string = [array componentsJoinedByString:@","];
NSLog(@"string:%@",string);

/*******************************************************************************************
NSMutableArray 可变数组
*******************************************************************************************/
/*---------------给数组分配容量----------------*/
//NSArray *array;
array = [NSMutableArray arrayWithCapacity:20];

/*--------------在数组末尾添加对象----------------*/
//- (void) addObject: (id) anObject;
//NSMutableArray *array = [NSMutableArray arrayWithObjects:
@"One",@"Two",@"Three",nil];
[array addObject:@"Four"];
NSLog(@"array:%@",array);

/*--------------删除数组中指定索引处对象----------------*/
//-(void) removeObjectAtIndex: (unsigned) index;
//NSMutableArray *array = [NSMutableArray arrayWithObjects:
@"One",@"Two",@"Three",nil];
[array removeObjectAtIndex:1];
NSLog(@"array:%@",array);
//被删除对象后面的数组元素被前移来填补空缺

/*-------------数组枚举---------------*/
//遍历索引
int i;
for (i=0; i<[array1 count]; i++)
{
NSLog(@"index %d has %@",i,[array1 objectAtIndex:i]);
}
//功能最强大

//- (NSEnumerator *)objectEnumerator;从前向后
//NSMutableArray *array = [NSMutableArray arrayWithObjects:
@"One",@"Two",@"Three",nil];
NSEnumerator *enumerator;
enumerator = [array objectEnumerator];
//创建一个泛型对象
id thingie;
//访问枚举数组的下一个对象，为nil时停止
while (thingie = [enumerator nextObject])

{
NSLog(@"thingie:%@",thingie);
}

//- (NSEnumerator *)reverseObjectEnumerator;从后向前
//NSMutableArray *array = [NSMutableArray arrayWithObjects:
@"One",@"Two",@"Three",nil];
NSEnumerator *enumerator;
enumerator = [array reverseObjectEnumerator];

id object;
while (object = [enumerator nextObject]) {
NSLog(@"object:%@",object);
}
//对可变数组进行遍历操作，对可变数据进行添加删除后，enumerator遍历的是之前创建的数组，不会时时更新；

//快速枚举
//NSMutableArray *array = [NSMutableArray arrayWithObjects:
@"One",@"Two",@"Three",nil];
for(NSString *string in array)
{
NSLog(@"string:%@",string);
}
NSmutableArray 常用方法总结array 创建一个空数组 +(id)arrayWithCapacity:size 创建一个数组，指定容量为size -(id)initWithCapacity:size 初始化一个新分配的数组，指定容量为size -(void)addObject:obj 将对象obj添加到数组末尾 -(void)insertObject:obj atIndex:i 将对象 obj 插入到索引为 i 的位置 -(void)replaceObject:obj atIndex:i 将数组中索引为 i 处的元素用obj 置换 -(void)removeObject:obj 从数组中删除所有是 obj 的对象 -(void)removeObjectAtIndex:i 从数组中删除索引为 i 的对像 -(void)sortUsingSelector:(SEL)selector 用 selector 只是的比较方法将数组排序
/*******************************************************************************************
NSDictionary
*******************************************************************************************/

/*------------------------------------创建字典------------------------------------*/
//- (id) initWithObjectsAndKeys;

NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys:@"One",@"1",@"Two",@"2",@"Three",@"3",nil];
NSString *string = [dictionary objectForKey:@"One"];
NSLog(@"string:%@",string);
NSLog(@"dictionary:%@",dictionary);
[dictionary release];

//
NSDictionary * tires;

tires =[NSDictionary dictionaryWithObjectsAndKeys:
t1,@"1"
,t2,@"2"
,t3,@"3"
,t4,@"4"
,nil];
NSLog(@"%@",tires);

/*******************************************************************************************
NSMutableDictionary
*******************************************************************************************/

/*------------------------------------创建可变字典------------------------------------*/
//创建
NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
//添加字典
[dictionary setObject:@"One" forKey:@"1"];
[dictionary setObject:@"Two" forKey:@"2"];
[dictionary setObject:@"Three" forKey:@"3"];
[dictionary setObject:@"Four" forKey:@"4"];
NSLog(@"dictionary:%@",dictionary);
//若已经存在该关键字，则会用新值替换原有值

//删除指定的字典
[dictionary removeObjectForKey:@"3"];
NSLog(@"dictionary:%@",dictionary);

/*******************************************************************************************
NSValue（对任何对象进行包装）
*******************************************************************************************/

/*--------------------------------将NSRect放入NSArray中------------------------------------*/
//将NSRect放入NSArray中
NSMutableArray *array = [[NSMutableArray alloc] init];
NSValue *value;
CGRect rect = CGRectMake(0, 0, 320, 480);
value = [NSValue valueWithBytes:&rect objCType:@encode(CGRect)];
[array addObject:value];
NSLog(@"array:%@",array);

//从Array中提取
value = [array objectAtIndex:0];
[value getValue:&rect];
NSLog(@"value:%@",value);

/*******************************************************************************************
从目录搜索扩展名为jpg的文件
*******************************************************************************************/

//NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *home;
home = @"../Users/";

NSDirectoryEnumerator *direnum;
direnum = [fileManager enumeratorAtPath: home];

NSMutableArray *files = [[NSMutableArray alloc] init];

//枚举
NSString *filename;
while (filename = [direnum nextObject]) {
if([[filename pathExtension] hasSuffix:@"jpg"]){
[files addObject:filename];
}
}

//快速枚举
//for(NSString *filename in direnum)
//{
//    if([[filename pathExtension] isEqualToString:@"jpg"]){
//        [files addObject:filename];
//    }
//}
NSLog(@"files:%@",files);

//枚举
NSEnumerator *filenum;
filenum = [files objectEnumerator];
while (filename = [filenum nextObject]) {
NSLog(@"filename:%@",filename);
}

//快速枚举
//for(id object in files)
//{
//    NSLog(@"object:%@",object);
//
/*******************************************************************************************
NSNumber
*******************************************************************************************/
//封装数据对象
[NSNumber numberWithChar:(char)value];
[NSNumber numberWithChar:(char)value];

[NSNumber numberWithChar:(char)value];

[NSNumber numberWithChar:(char)value];

[NSNumber numberWithChar:(char)value];