Downloading a file from url and saving to resources on iPhone
Is it possible to download a file (i.e. an sqlite database file) from the Internet into your iPhone application programmatically for later use within the application?
I am trying using NSURLConnection
, but not able to save the 开发者_如何学运维file.
Here is the example code I am trying:
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *file = [NSString stringWithFormat:@"http://en.wikipedia.org/wiki/Text_file"];
NSURL *fileURL = [NSURL URLWithString:file];
NSURLRequest *req = [NSURLRequest requestWithURL:fileURL];
NSURLConnection *conn = [NSURLConnection connectionWithRequest:req delegate:self];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[self.fileData setLength:0];
self.totalFileSize = [NSNumber numberWithLongLong:[response expectedContentLength]];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.fileData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSArray *dirArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSLog(@"%@", [dirArray objectAtIndex:0]);
NSString *path = [NSString stringWithFormat:@"%@/blah.text", [dirArray objectAtIndex:0]];
if ([self.fileData writeToFile:path options:NSAtomicWrite error:nil] == NO) {
NSLog(@"writeToFile error");
}
else {
NSLog(@"Written!");
}
}
What is fileData? How is it defined and initialized?
fileData = [NSMutableData data];
should be somewhere after:
NSURLConnection *conn = [NSURLConnection connectionWithRequest:req delegate:self];
You have to initialize fileData and retain it per memory management rules.
Try it with my answer. It Works!
You need to expand the path with stringByAppendingPathComponent
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"bookdb.sql"];
Try this code in a method and execute,
NSURL *url=[NSURL URLWithString:@"http://en.wikipedia.org/wiki"];
NSData *dbFile = [[NSData alloc] initWithContentsOfURL:url];
NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle] resourcePath] stringByDeletingLastPathComponent]stringByAppendingPathComponent:@"Documents"]];
NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"Text_file.txt"];
[dbFile writeToFile:filePath atomically:YES];
This can be useful for you.
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 automically:YES];
}
Note that this is a writeToFile
method is synchronous, so it will halt/block your UI.
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