iOS photo extension finishContentEditingWithComple

问题:

My photo extension app has access to both Camera and Photos. All is ok, but when pressing Done, it can not save image.

Code of standard completion handler:

- (void)finishContentEditingWithCompletionHandler:(void (^)(PHContentEditingOutput *))completionHandler {
    // Update UI to reflect that editing has finished and output is being rendered.

    // Render and provide output on a background queue.
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        PHContentEditingOutput *output = [[PHContentEditingOutput alloc] initWithContentEditingInput:self.input];

        NSError* error = nil;

        NSData *renderedJPEGData = UIImageJPEGRepresentation(filtered_ui_image, 1.0);
        assert(renderedJPEGData != nil);
        //BOOL written_well = [renderedJPEGData writeToURL:output.renderedContentURL atomically:YES];

        BOOL written_well = [renderedJPEGData writeToURL:output.renderedContentURL options:NSDataWritingAtomic error:&error];
        assert(written_well);



        // Call completion handler to commit edit to Photos.
        completionHandler(output);
    });
}

renderedJPEGData is not nil,
error is nil, thus function [NSData writeToURL] was successful,
written_well is YES,

when debugging line-by-line, after block finishes, an alert appears:

output.renderedContentURL is /private/var/mobile/Containers/Data/PluginKitPlugin/509C1A04-D414-4DB7-B1E6-83C47FC88BC9/tmp/blah_blah_name.JPG

So, I have permissions, debug shows no errors, what can I try to detect the cause of problem?

回答1:

As of iOS 10, the adjustment data must have at least one byte. This is a breaking change from iOS 9, where the adjustment data can be nil. I've tested this on both iOS 9 and iOS 10 to confirm.

Additional documentation: https://developer.apple.com/reference/photos/phcontenteditingoutput/1518684-adjustmentdata

PHContentEditingOutput* output = [[PHContentEditingOutput alloc] initWithContentEditingInput:self.input];
NSMutableData* adjustmentData = [NSMutableData data];
uint8_t byte = 1;
[adjustmentData appendBytes:&byte length:1];
output.adjustmentData = [[PHAdjustmentData alloc] initWithFormatIdentifier:@"com.yourcompany.yourapp" formatVersion:@"1.0f" data:adjustmentData];

回答2:

Even though the header implies that adjustmentData can be nil, the documentation states:

If you write new asset content to the URL specified by the renderedContentURL property, you must also provide a new, distinct PHAdjustmentData object describing your edit. Passing a preexisting adjustment data object (that describes an earlier edit) results in undefined behavior.

So do something like this before calling the completion handler:

output.adjustmentData = [[PHAdjustmentData alloc] initWithFormatIdentifier:@"com.whatever.app" formatVersion:@"1.0" data:[NSData data]];