NSString *stringURL = @"http://www.somewhere.com/thefile.png";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
if ( urlData )
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"filename.png"];
[urlData writeToFile:filePath atomically:YES];
}上面範例是放到 Document 裡。
You can access the Caches directory like this. I use this method for getting file data…
- (NSString *)getFileData: (NSString *)fileDirPath
{
NSArray *myPathList = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *myPath = [myPathList objectAtIndex:0];
NSError *err = nil;
NSString *fData = @"";
myPath = [myPath stringByAppendingPathComponent:fileDirPath];
if([[NSFileManager defaultManager] fileExistsAtPath:myPath])
{
fData = [NSString stringWithContentsOfFile:myPath encoding:NSUTF8StringEncoding error:&err];
if(err) NSLog(@"getFileData() - ERROR: %@",[err localizedDescription]);
}
else
{
NSLog(@"getFileData() - ERROR: This file '%@' does not exist",myPath);
}
return fData;
}範例2號：
//Method writes a string to a text file
-(void) writeToTextFile{
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the documents directory:
NSString *fileName = [NSString stringWithFormat:@"%@/textfile.txt",
documentsDirectory];
//create content - four lines of text
NSString *content = @"One\nTwo\nThree\nFour\nFive";
//save content to the documents directory
[content writeToFile:fileName
atomically:NO
encoding:NSStringEncodingConversionAllowLossy
error:nil];
}
//Method retrieves content from documents directory and
//displays it in an alert
-(void) displayContent{
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the documents directory:
NSString *fileName = [NSString stringWithFormat:@"%@/textfile.txt",
documentsDirectory];
NSString *content = [[NSString alloc] initWithContentsOfFile:fileName
usedEncoding:nil
error:nil];
//use simple alert from my library (see previous post for details)
[ASFunctions alert:content];
[content release];
}
from: