IOS NSString 截取，objectAtIndex，rangeOfString，stringWithContentsOfFile，NSEnu ...

小结：

1）componentsSeparatedByString:截取指定字符串；

2) pathForResource：获取程序运行时目录

3) objectAtIndex:获取当前索引的字符串；

4) rangeOfString:获取指定短字符串在长字符串中的开始，结尾索引值；

5) stringWithContentsOfFile：按行读取文件

6) componentsSeparatedByString:@"\n"];换行分割字符串；

7) NSEnumerator *nse = [lines objectEnumerator];
将数组转换为NSEnumerator，可向前读取数据；

8) nextObject：读取下一行数据；

void splitString(){
NSString *animals =
@"dog#cat#pig";

//将#分隔的字符串转换成数组
NSArray *array = [animals
componentsSeparatedByString:@"#"];
NSLog(@"animals:%@",array);

//获取程序运行时目录
NSString *escapedPath = [[NSBundle
mainBundle] pathForResource:@"info"
ofType:@"plist"];
NSArray *strings = [escapedPath
componentsSeparatedByString:
@"/"];
NSString *tmpFilename = [strings
objectAtIndex:[strings
count]-1];
NSRange iStart = [escapedPath
rangeOfString : tmpFilename];
NSString *runtimeDirectory = [escapedPath
substringToIndex:iStart.location-1];
NSLog(@"runtimeDirectory:%@",runtimeDirectory);

//按行读取文件

NSString *tmp;
NSArray *lines = [[NSString
stringWithContentsOfFile:@"test.txt"
encoding:nil
error:nil]

componentsSeparatedByString:@"\n"];

NSEnumerator *nse = [lines
objectEnumerator];

while(tmp = [nse
nextObject]) {
NSLog(@"tmp:%@", tmp);
}

}