NSDictionary的深度可变副本到NSMutableDictionary中

Question

我有一个属性列表,我读入NSDictionary,我想从中创建一个可变副本到NSMutableDictionary来编辑内容,然后能够通过复制原始内容来重置可变字典.

NSDictionary *defaultRows;
NSMutableDictionary *rows;

NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"Config" ofType:@"plist"];
defaultRows = [[[NSDictionary alloc] initWithContentsOfFile: plistPath] objectForKey:@"rows"];

这就是我尝试创建原始字典的副本(根据Apple的建议):

rows = [NSMutableDictionary dictionaryWithDictionary: defaultRows];

当我尝试用以下内容更改字典行的内容时:

[[[rows objectForKey:self.company.coaTypeCode] objectForKey:statementType] removeObjectsAtIndexes:rowsToDelete];

我收到运行时错误*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray removeObjectAtIndex:]: mutating method sent to immutable object'.

我在这里阅读了这篇文章,但想知道是否有更优雅的方法来实现深层拷贝？

Answer 1

由于defaultRows从属性列表加载,最简单的方法是使用可变容器反序列化属性列表.

NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"Config" ofType:@"plist"];
NSData *rowsData = [NSData dataWithContentsOfFile:plistPath];

NSMutableDictionary *rows = [NSPropertyListSerialization propertyListWithData:rowsData
    options:NSPropertyListMutableContainers format:NULL error:NULL];