如何把一个Dictionary对象的键值都取出来，然后拼接到一起，达到string str=key1+value1+key2+value2+??

StringBuilder sb = new StringBuilder();
Dictionary<string, string> dict = new Dictionary<string, string>();
//...添加键值操作
foreach (var kv in dict)//如果是.NET2.0 var换成KeyVal