尝试将值写入plist时获取错误

Question

我正在尝试将值写入plist，但有错误

代码：

NSString *path = [[NSBundle mainBundle] pathForResource:@"Properties" ofType:@"plist"];
    NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:path];
    [dict setObject:[NSNumber numberWithInt:Quant] forKey:@"Quant"];
    [dict writeToFile:path atomically:YES];

错误：

No visible @interface for 'NSDictionary' declares the selector 'setObject:forKey:'

Answer 1

您无法修改不可变的NSDictionary。你必须使用可变副本：

NSMutableDictionary *dict = [[[NSDictionary alloc] initWithContentsOfFile:path] mutableCopy];