Crash while custom IPhoto Protocol Implement

[陈]

Why not declare in IDMPhoto protocol instead force convert ?

- (void)configurePage:(IDMZoomingScrollView *)page forIndex:(NSUInteger)index {
	page.frame = [self frameForPageAtIndex:index];
    page.tag = PAGE_INDEX_TAG_OFFSET + index;
    page.photo = [self photoAtIndex:index];

    __block __weak IDMPhoto *photo = (IDMPhoto*)page.photo; // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    __weak IDMZoomingScrollView* weakPage = page;
    photo.progressUpdateBlock = ^(CGFloat progress){
        [weakPage setProgress:progress forPhoto:photo];
    };
}

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