golang 无法为结构分配接口 {}

Question

专家您好，我正在使用此库将 K/V 存储在缓存中

"github.com/bluele/gcache"

我存储的值就是这个数据结构

type LatestBlockhashCacheResult struct {

    Blockhash            string `json:"blockhash"`

    LastValidBlockHeight uint64 `json:"lastValidBlockHeight"` // Slot.

    CommitmentType  string `json:"commitmentType"`

}

lbhr := LatestBlockhashCacheResult{

            Blockhash:            lbh.Value.Blockhash.String(),

            LastValidBlockHeight: lbh.Value.LastValidBlockHeight,

            CommitmentType:       string(commitmentType),

        }

        gc.SetWithExpire(lbh.Value.LastValidBlockHeight, lbhr, time.Hour*10)

我对检索缓存没有问题，但无法对其进行类型转换

c, _ := gc.Get(rf.LastValidBlockHeight)

    fmt.Printf("%T\n", c)

所以当我尝试这个

var c = LatestBlockhashCacheResult{}

    c, _ = gc.Get(rf.LastValidBlockHeight)

这引发了我的错误

 cannot assign interface {} to c (type LatestBlockhashCacheResult) in multiple assignment: need type assertion

Answer 1

您正在尝试分配interface{}给类型化变量。为此，您需要首先尝试将interface{}值转换为特定类型val, err := gc.Get(rf.LastValidBlockHeight)if err != nil {  // handle }c, ok := val.(LatestBlockhashCacheResult)if !ok {   // val has different type than LatestBlockhashCacheResult}参考：https://go.dev/tour/methods/15https://go.dev/tour/methods/16