about the NSInputstream

-(NSString*)dateFilePath{

NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory=[paths objectAtIndex:0];

return [documentsDirectory stringByAppendingPathComponent:kFileName];开发者_JS百科
}


- (void)viewDidLoad
{

int actuallyRead=0;

NSString *path=[self dateFilePath];

NSURL *audiourl=[[NSURL alloc]initFileURLWithPath:path];

NSLog(@"%@",audiourl);

inStream=[[NSInputStream alloc]initWithURL:audiourl];

actuallyRead=[inStream read:buffer maxLength:sizeof(buffer)];

NSLog(@"%d",actuallyRead);

[dataBuffer1 appendBytes:buffer length:actuallyRead];

NSLog(@"%d",actuallyRead);

[inStream release];

[super viewDidLoad];

}
IN .h file
NSInputStream  *inStream;
NSMutableData  *dateBuffer1;
unint8_t       buffer[1024];

There in a file in Documents,I want to load into buffer use this method,but actuallyRead always -1, is there some wrong in my method?

The reason you always get -1, is that you forgot to open the stream, so all you have to do is insert the line [inStream open]; after you initialized your NSInputStream and before you try to read from it.

You should check if the inStream is available by

if (nil == inStream)