iphone - NSMutableArray 替换对象

Question

我尝试在数组中查找对象，如果成功，我需要将数组中的对象替换为新对象

 for (id existingSig in allSignature)
   if ([[existingSig objectForKey:@"SignatureName"] isEqualToString:[item objectForKey:@"name"]])
    {    
      [allSignature removeObject:existingSig];
      [allSignature addObject:[NSDictionary dictionaryWithObjectsAndKeys:@"1", @"SignatureIsRich", [item objectForKey:@"name"], @"SignatureName", generatedID, @"SignatureUniqueId", nil]];
     }

我遇到错误“NSCFArray: 0x100551f10> 在枚举时发生突变”

Answer 1

正如其他人所说，当 MutableArray 被枚举时，你不能改变它。您可以通过在循环后使用两个数组来处理它，其中包含要删除的内容和要添加的内容。

NSMutableArray *remove = [NSMutableArray array];
NSMutableArray *add = [NSMutableArray array];
for (id existingSig in allSignature){
   if ([[existingSig objectForKey:@"SignatureName"] isEqualToString:[item objectForKey:@"name"]])
    {    
      // Add to the array of objects to be removed
      [remove addObject:existingSig];
      // Add to the array of objects to be added
      [add addObject:[NSDictionary dictionaryWithObjectsAndKeys:@"1", @"SignatureIsRich", [item objectForKey:@"name"], @"SignatureName", generatedID, @"SignatureUniqueId", nil]];
     }
}
[allSignature removeObjectsInArray:remove]; // Remove objects
[allSignature addObjectsFromArray:add]; // Add new objects