First, the concept of NSData
1, the use of the file needs to be frequently read into a temporary storage area, which is often called a buffer
2. The NSData class provides a simple way to set a buffer, read the contents of a file into a buffer, or write the contents of a buffer to a file.
3. NSData cache up to 2GB for 32-bit applications
4. We have two definitions of nsdata (immutable buffers), nsmutabledata (variable buffers)
NSData *filedata; Nsfilemanager *filemanager = [[Nsfilemanager alloc]init];filedata = [FileManager Contentsatpath:path]; [FileManager createfileatpath:path2 contents:filedata Attributes:nil]; Take the default property value
nsdata< Span style= "LINE-HEIGHT:34PX; font-size:14pt; " > -> NSString< Span style= "LINE-HEIGHT:34PX; font-size:14pt; " >
NSString *strdata = [[NSString alloc]initwithdata:filedata encoding:nsasciistringencoding];
Type conversion nsstring- nsdata: