PHImageFileSandboxExtensionTokenKey。取到空

NSString * sandboxExtensionTokenKey = info[@"PHImageFileSandboxExtensionTokenKey"];
NSArray * arr = [sandboxExtensionTokenKey componentsSeparatedByString:@";"];
NSString * filePath = arr[arr.count - 1];
DLog(@" ---- 这个类--------%@",asset);
if (filePath.length == 0) {
if ([asset isKindOfClass:[AVURLAsset class]]) {
AVURLAsset *urlAsset = (AVURLAsset *)asset;
NSString *oathUrl = [urlAsset.URL absoluteString];
NSString *str2 = [oathUrl substringFromIndex:7];
NSString *str4 = [NSString stringWithFormat:@"/private%@",str2];//str4 = "zero"
filePath = str4;
}
}