iOS 字符串读写

1）从文件读取字符串:initWithContentsOfFile方法  

1. NSString *path = @"string.txt";  
2. NSString *astring = [[NSString alloc] initWithContentsOfFile:path];  
3. NSLog(@"astring:%@",astring);  
4. [astring release]; //astring=nil;  

2）写字符串到文件:writeToFile方法  

1. NSString *astring = [[NSString alloc] initWithString:@"Hello!"];  
2. NSLog(@"astring:%@",astring);  
3. NSString *path = @"string.txt";      
4. [astring writeToFile: path atomically: YES];  
5. [astring release];  //astring=nil;