如何将动态值传递给pfquery？

Question

如何将动态值传递给plist的解析查询，以下代码不会检索任何数据？

NSString *path = [[NSBundle mainBundle]pathForResource:@"filter" ofType:@"plist"];
NSDictionary *dict = [[NSDictionary alloc]initWithContentsOfFile:path];
self.featured = [dict objectForKey:@"Featured"];
self.percentageHigh = [dict objectForKey:@"PercentageHigh"];
self.percentageLow = [dict objectForKey:@"PercentageLow"];

PFQuery *query = [PFQuery queryWithClassName:self.parseClassName];
[query whereKey:@"dsPercentage" lessThanOrEqualTo:self.percentageHigh];