main.go

package main

import (
	"fmt"
	"geth_less/mycontract"
	"log"
	"sync"

	"github.com/ethereum/go-ethereum/accounts/abi/bind/v2"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/ethclient"
)

var (
	onceClient sync.Once
	client     *ethclient.Client
)

func NewWsEthClient() (*ethclient.Client, error) {
	var err error
	onceClient.Do(func() {
		client, err = ethclient.Dial("wss://sepolia.infura.io/ws/v3/9be5f0c0b2794f44bb068af11b93a3c1")
		if err != nil {
			log.Fatal(err)
		}
	})
	return client, err
}

// 订阅
func main() {
	client, err := NewWsEthClient()
	if err != nil {
		log.Fatal("connect err:", err)
	}
	contractAddr := common.HexToAddress("0xd5aab6B48Ab960bD7377ABc18Eff6c841879B839")
	contractInstance, err := mycontract.NewMain(contractAddr, client)
	if err != nil {
		log.Fatal("create contract instance fail:", err)
	}

	eventChan := make(chan *mycontract.MainSetNumberEvent)

	sub, err := contractInstance.WatchSetNumberEvent(&bind.WatchOpts{Start: nil}, eventChan, nil)
	if err != nil {
		log.Fatal("watch event fail:", err)
	}
	defer sub.Unsubscribe()
	select {
	case event := <-eventChan:
		fmt.Printf("收到事件:numbner:%s,区块号：%d,交易号：%s", event.Number, event.Raw.BlockNumber, event.Raw.TxHash.Hex())
	case err := <-sub.Err():
		log.Fatal("watch event fail:", err)
	}
	fmt.Println("end")
}