NSValues不能保存在plist（这是什么writeToFile：atomically：）。查看此处您可以保存的值。 （NSNumber是一种NSValue，你可以保存，但其他NSValues将失败。）

NSValues can't be saved in a plist (which is what writeToFile:atomically: does). Take a look here for the values you can save. (NSNumber is a kind of NSValue you can save, but other NSValues will fail.)

如果你想用NSValues保存数组，你可以使用归档，而不是writeToFile：atomically :. NSArray和NSValue都支持归档，因此您只需将数组转换为归档并将该数据保存到文件即可。 （它将包括NSValues）。代码看起来像这样：

If you want to save your array with NSValues, you can use archiving instead of writeToFile:atomically:. NSArray and NSValue both support archiving, so you just convert the array to an archive and save that data to a file. (It will include the NSValues as well.) The code looks something like this:

[NSKeyedArchiver archiveRootObject:myArray toFile:@"myPath"];

要加载它，只需使用：

NSArray *myArray = [NSKeyedUnarchiver unarchiveObjectWithFile:@"myPath"];