1.1 NSRange
NSRange range = NSMakeRange(2, 4);//location＝2，len＝4
NSString *str = @"i love oc";
//查找对应的字符串的位置location,length
range = [str rangeOfString:@"love"];
4.2 NSMutableString
// NSMutableString可变字符串
NSMutableString *s1 = [NSMutableString stringWithFormat:@"age is 10"];
[s1 appendString:@"love"];
NSRange range = [s1 rangeOfString:@"love"];
[s1 deleteCharactersInRange:range];
4.3 NSString
//类方法构造字符串
NSString *str = [NSString stringWithFormat:@"age is %d",10];
NSString *str1 = [NSString stringWithContentsOfURL:url
encoding:NSUTF8StringEncoding error:nil];
//对象方法构造字符串
NSString *str1 = [[NSString alloc]initWithContentsOfFile:@"/Users/zhangct/Desktop/1.txt"encoding:NSUTF8StringEncoding error:nil];
NSString *url = @"file:///Users/zhangct/Desktop/1.txt";
NSString *str2 = [[NSString alloc]initWithContentsOfURL:urlencoding:NSUTF8StringEncoding error:nil];
//讲字符串写入文件
[str2 writeToFile]
//常用属性
[s length]
[s characterAtIndex:i]
//结构体类型转换成字符串
NSStringFromCGRect(<#CGRect rect#>)
NSStringFromCGPoint(<#CGPoint point#>)
4.4 NSString (NSExtendedStringDrawing)
//根据字体计算字符串的显示宽高
NSString *nikeName = @"内涵段子";
NSDictionary *attri = @{NSFontAttributeName: [UIFont systemFontOfSize:13]};
CGSize nikeSize = [nikeName boundingRectWithSize:CGSizeMake(MAXFLOAT, MAXFLOAT)
options:NSStringDrawingUsesLineFragmentOrigin attributes:attri context:nil].size;
4.5 NSBundle
//获取文件绝对路径
NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];
//加载xib试图文件，返回对象数组
NSArray *objs = [[NSBundle mainBundle] loadNibNamed:@"HMAppView" owner:nil options:nil];
.png)
// infoDictionary获取info.plist的字典信息
NSDictionary *dict = [[NSBundle mainBundle] infoDictionary];
// objectForInfoDictionaryKey获取info.plist字典中某一个键值
NSString *versonKey = (__bridge NSString *)kCFBundleVersionKey;
NSString *verson = [[NSBundle mainBundle] objectForInfoDictionaryKey:versonKey];
1.2 NSArray和NSMutableArray
//读取文件内容填充NSArray集合
NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];
//向数组中每个元素发送SEL消息
array makeObjectsPerformSelector:@selector(<#selector#>)
[self.answerView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
1.3 NSSet
//获取集合个数
NSLog(@"set1 count :%d", set1.count);
//以数组的形式获取集合中的所有对象
NSArray *allObj = [set2 allObjects];
NSLog(@"allObj :%@", allObj);
//获取任意一对象
NSLog(@"anyObj :%@", [set3 anyObject]);
//是否包含某个对象
NSLog(@"contains :%d", [set3 containsObject:@"obj2"]);
//是否有交集
NSLog(@"intersect obj :%d", [set1 intersectsSet:set3]);
//是否完全匹配
NSLog(@"isEqual :%d", [set2 isEqualToSet:set3]);
//set2是否是set1的子集合
NSLog(@"isSubSet :%d", [set2 isSubsetOfSet:set1]);
1.4 NSMutableSet
//集合元素相减
[mutableSet1 minusSet:mutableSet2];
//只留下相等元素
[mutableSet1 intersectSet:mutableSet3];
//合并集合
[mutableSet2 unionSet:mutableSet3]
//删除指定元素
[mutableSet2 removeObject:@"a"];
//删除所有数据
[mutableSet2 removeAllObjects];
1.5 NSDictionary和NSMutableDictionary
NSDictionary *dict = @{@"name": @"zhangct", @"age": @20};
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setValue:@"zhangct" forKey:@"name"];
1.6 NSNumber
NSNumber *num1 = [NSNumber numberWithInt:10];
[num1 intValue];
NSNumber *num2 = [NSNumber numberWithFloat:1.0];
[num2 floatValue];
NSNumber *num3;
int age = 20;
num3 = @(age);
num3 = @100;
1.7 NSValue
CGPoint p = CGPointMake(10, 20);
NSValue *value = [NSValue valueWithPoint:p];
NSLog(@"%@", NSStringFromPoint([value pointValue]));
1.8 NSDate
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy年MM月dd日 HH时mm分ss秒";
NSDate *date = [NSDate date];
NSLog(@"%@", [formatter stringFromDate:date]);
4.6 NSObject
4.6.1 NSObject
[self performSelector:@selector(onClick:value1:) withObject:nil withObject:nil];
performSelector是执行self对象中的onClick:value1:方法，最多支持传递2个参数.
4.6.2 NSObject(NSDelayedPerforming)
//播放完毕后延迟1秒执行释放内存
[self.tom performSelector:@selector(setAnimationImages:)
withObject:nil afterDelay:self.tom.animationDuration + 1.0f];
4.6.3 NSObject(NSKeyValueCoding)
//单个赋值
[self setValue:dict[@"answer"] forKey:@"answer"];
[self setValue:dict[@"title"] forKey:@"title"];
//ForKeyPath取值，返回Person的car name
[p valueForKeyPath:@"car.name"]
//ForKeyPath取值返回title数组
carsGroups valueForKeyPath:@"title"
//字典转模型，使用此方法要保证属性名称和字典的key同名
[self setValuesForKeysWithDictionary:dict];
//模型转字典
NSDictionary *dict = [p dictionaryWithValuesForKeys:@[@"name", @"age"]];
4.6.4 NSObject(UINibLoadingAdditions)
//当xib文件加载完毕后执行
- (void)awakeFromNib;
4.8 NSIndexPath
//根据分组和行号初始化对象
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:10 inSection:0];
//返回分组
indexPath.section
//返回行号
indexPath.row