//取得mainBundle
NSBundle *bundle = [NSBundle mainBundle];
//取得文件路径
NSString *plistPath = [bundle pathForResource:@"文件名" ofType:@"plist"];
// 或可以写成
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"文件名" ofType:@"plist"];
NSDictionary *dictionary
= [[NSDictionary alloc] initWithContentsOfFile:plistPath];