此处的数据类型是关键。 mdi 实际上不是地图，而是 interface {} ，它可以是任何东西-地图，字符串，一个int。您需要首先将其声明为具有预期键/值类型的映射，或者执行 JSON和Go 。

The data type here was the key. mdi was not actually a map, but an interface{}, which could be anything - a map, a string, an int. You need to assert it to a map with expected key/value types first, or do the awkward case switch outlined in JSON and Go.

mdi, err := page.Metadata()
md, ok := mdi.(map[string]interface{})
fmt.Println(md["title"])