英文:
golang cannot assign interface {} for struct
问题
你好，以下是翻译好的内容：
你好，专家。我正在使用这个库来存储键值对到缓存中：
"github.com/bluele/gcache"
我存储的值是这个数据结构：
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)
我可以成功检索缓存，但无法进行类型转换：
c, _ := gc.Get(rf.LastValidBlockHeight)
fmt.Printf("%T\n", c)
所以当我尝试这样做时：
var c = LatestBlockhashCacheResult{}
c, _ = gc.Get(rf.LastValidBlockHeight)
这会抛出错误：
在多重赋值中无法将接口{}分配给c（类型为LatestBlockhashCacheResult）：需要类型断言
英文:
Hello Expert I'm using this libraray to store K/V in cache
"github.com/bluele/gcache"
The value which I store is this Data Structure
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)
I have no problem with retrieving the cache but not able to Typecast it
c, _ := gc.Get(rf.LastValidBlockHeight)
fmt.Printf("%T\n", c)
So when i Try this
var c = LatestBlockhashCacheResult{}
c, _ = gc.Get(rf.LastValidBlockHeight)
This throws me error
cannot assign interface {} to c (type LatestBlockhashCacheResult) in multiple assignment: need type assertion
答案1
得分: 2
你正在尝试将interface{}赋值给一个有类型的变量。为了做到这一点，你需要首先尝试将interface{}值转换为特定的类型。
val, err := gc.Get(rf.LastValidBlockHeight)
if err != nil {
// 处理错误
}
c, ok := val.(LatestBlockhashCacheResult)
if !ok {
// val的类型与LatestBlockhashCacheResult不同
}
参考链接：
https://go.dev/tour/methods/15
https://go.dev/tour/methods/16
英文:
You are trying to assign interface{} to a typed variable.
In order to do this you need first try to cast the interface{} value to a specific type
val, err := gc.Get(rf.LastValidBlockHeight)
if err != nil {
// handle
}
c, ok := val.(LatestBlockhashCacheResult)
if !ok {
// val has different type than LatestBlockhashCacheResult
}
Refs:
https://go.dev/tour/methods/15
https://go.dev/tour/methods/16
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