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This article mainly explains "go language block chain how to call intelligent contract", interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Now let the editor to take you to learn "go language block chain how to invoke intelligent contracts"!

1. The API for obtaining abi file contracts

After compiling the contract in the remix tool, there will be an abi, copy

Then create a new xx.abi file and paste the assigned values into it.

Note: the code has changed, and the abi will change after recompilation, so be sure to use the latest abi

You can also generate abi through solc:

Solc-- bin test.sol-o test.abi

two。 Install abigen tools

Used to generate go files

Download file: github address

Find the main.go file, go build it, and generate the abigen.exe file.

And put it here in the bin directory.

And then you can verify it here.

Use the abigen tool to generate go files

Abigen-abi xx.abi-pkg packagename-type structname-out xx.go

When abi files are deployed in remix, you can get the package name of the output file specified by pkg, that is, the package name, type, the contract structure name, out, the output go file name.

3. Remix connection private chain

Geth starts private chain. Specify rpccorsdomain *, otherwise it will not be connected in remix.

Select Web3 Provider mode. The private chain port 8545 is connected by default.

But you can see that we don't have account here.

So we can create an account

After creating two

You can see it here.

4. Contract deployment

1. Connect private chain: select Web3 Provider. The default port number is 8545. If the rpc port number started by geth is inconsistent, change it to consistent.

two。 Deployment contract

The following errors may occur and the solutions are listed accordingly

1. Error: authentication needed: password or unlock: this kind of error report can unlock the account.

Account unlocked: personal.unlockAccount ("account address")

Unlock will be fine.

2. Returned error: exceeds block gaslimit: if this error occurs, it depends on the gaslimit of the block number, and change it to always

Get the block number: eth.blockNumber

Get details based on the block number: eth.getBlock (0) will see the value of gasLimit, and the gaslimit cannot be greater than this at deployment time

3. Returned error: insufficient funds for gas * price + value: deployment contract requires a handling fee and has to be earned through mining

If you have no money, you have to dig a mine to make money.

Start mining with specified number of threads: miner.start (1)

Stop digging: miner.stop ()

Check for mining: eth.mining true: digging, false: not digging

Get an array of account addresses: eth.accounts

Get the mining address: the first account created by eth.coinbase by default

Check the first account balance: eth.getBalance (eth.accounts [0])

Get the balance of the specified account: eth.getBalance ("account address")

5. Initialize the private chain node creation block

Create a new genesis.json file with the following contents

{"config": {"chainId": 15, "homesteadBlock": 0, "eip155Block": 0, "eip158Block": 0}, "coinbase": "0x0000000000000000000000000000000000000000", "difficulty": "0x40000", "extraData": "," gasLimit ":" 0xffffffff "," nonce ":" 0x0000000000000042 "," mixhash ":" 0x0000000000000000000000000000000000000000000000000000000000000000 "," parentHash ":" 0x0000000000000000000000000000000000000000000000000000000000000000 "," timestamp ":" 0x00 " "alloc": {}}

Meaning:

Coinbase: address of mining account, which can be set later. Generally, it defaults to the first user created.

Difficulty: it is difficult to set the current block. If it is too difficult, it will be very difficult for cpu mining. It is less difficult to set it here.

GasLimit: this value sets the limit on the total consumption of GAS, which is used to limit the sum of transaction information that can be contained in the block. Enter the maximum.

Nonce: nonce is a 64-bit random number used for mining. Note that the settings of him and mixhash need to meet the Yellow paper of Ethernet Square.

Mixhash: hash generated by part of the previous block for mining in conjunction with nonce.

ParentHash: the hash value of the previous block. Because it is a Genesis block, this value is 0extraData:

Timestamp: sets the timestamp of the creation block

Alloc: the number of Ethernet coins used to preset accounts and accounts. Because it is easy to mine private chains, we do not need to preset accounts with coins. We can create them when we need them.

Cmd enters the path where the json file is stored

Geth-datadir "fanone" init genesis.json

6. Contract deployment

You need to pay a handling fee when you deploy.

Http://ethscan.hubwiz.com/

7. Call

Github.com/ethereum/go-ethereum v1.10.0

Package mainimport ("github.com/ethereum/go-ethereum/ethclient"github.com/ethereum/go-ethereum/common"eth_block/utils/contract/abi"fmt"github.com/ethereum/go-ethereum/accounts/abi/bind") func main () {/ / Connect rpc client Err: = ethclient.Dial ("http://127.0.0.1:8545") / / define the address of the account to operate the contract addr: =" 0x29794ab2ed6c47faff7ebdd6dcdd71a263e25460 "/ / convert the string address to common.Address common_addr: = common.HexToAddress (addr) if err! = nil {panic (" connection to ethernet contract error ")} / / create the contract object contract_obj Err11: = contract.NewTestAddress (common_addr,client) if err11! = nil {panic ("error creating contract object")} fmt.Println (contract_obj.TestAddressCaller) / / Caller access function fmt.Println (contract_obj.TestAddressTransactor) / / Transactor has a function fmt.Println (contract_obj.TestAddressFilterer) / / has no effect} so far I believe that you have a deeper understanding of "go language blockchain how to invoke intelligent contracts", you might as well do it in practice! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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