I am making a small app where the user can create a game profile, input some data and a picture that can be taken with the camera.
I save most of that profile data with the help of NSUserDefaults
, but a friend discouraged me from saving the profile image in NSUserDefault
.
What's the proper way to save and retrieve images locally in my a开发者_JAVA百科pp?
You should save it in Documents
or Cache
folder. Here is how to do it.
Saving into Documents
folder:
NSString* path = [NSHomeDirectory() stringByAppendingString:@"/Documents/myImage.png"];
BOOL ok = [[NSFileManager defaultManager] createFileAtPath:path
contents:nil attributes:nil];
if (!ok)
{
NSLog(@"Error creating file %@", path);
}
else
{
NSFileHandle* myFileHandle = [NSFileHandle fileHandleForWritingAtPath:path];
[myFileHandle writeData:UIImagePNGRepresentation(yourImage)];
[myFileHandle closeFile];
}
Loading from Documents
folder:
NSFileHandle* myFileHandle = [NSFileHandle fileHandleForReadingAtPath:path];
UIImage* loadedImage = [UIImage imageWithData:[myFileHandle readDataToEndOfFile]];
You can also use UIImageJPEGRepresentation
to save your UIImage
as a JPEG
file. What's more if you want to save it in Cache
directory, use:
[NSHomeDirectory() stringByAppendingString:@"/Library/Caches/"]
One way to do this is use the application's document directory. This is specific to a application and will not be visible to other applications.
How to create this:
Just add a static function to App Delegate and use the function where ever the path is required.
- (NSString )applicationDocumentDirectory {
/
Returns the path to the application's documents directory.
*/
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
return basePath;
}
Hope it Helped..I think this("iphone-user-defaults-and-uiimages") post addresses your issue. Don't save blobs to a property list such as NSUserDefaults. In your case I would write to disk directly instead.
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