// 初始化群属性
GroupAttributes attributes = new GroupAttributes
{
  group_atrribute_key = "key",
  group_atrribute_value = "value"
};
TIMResult res = TencentIMSDK.GroupInitGroupAttributes(group_id, attributes, (int code, string desc, string user_data)=>{
 // 处理异步逻辑
});

// 删除群属性
GroupAttributes attributes = new List<string>
{
  "attr1"
};
TIMResult res = TencentIMSDK.GroupDeleteGroupAttributes(group_id, attributes, (int code, string desc, string user_data)=>{
 // 处理异步逻辑
});

// 获取群属性
GroupAttributes attributes = new List<string>
{
  "attr1"
};
TIMResult res = TencentIMSDK.GroupGetGroupAttributes(group_id, attributes, (int code, string desc, List<GroupAttributes> attributes, string user_data)=>{
 // 处理异步逻辑
});

TencentIMSDK.SetGroupAttributeChangedCallback((string group_id, List<GroupAttributes> group_attributes, string user_data)=>{
 // 处理回调逻辑
});