当我在合同上使用 运行 方法时，如何获得 运行ning 结果？
How can I get the running result when I run method on contract?
我想写一个简单的函数来调用合约的方法并得到 运行 结果，
这是合约代码
function _evaluate(uint8[5] _uploads) internal returns (bytes32 resultId){
resultId= keccak256(abi.encodePacked(now, msg.sender));
addressToid[msg.sender] = resultId;
idToResult[resultId] = Result(msg.sender, r);
}
function upload(uint8[5] _inputs) public returns ( bytes32 resultId) {
return _evaluate(_inputs);
}
前端js代码
// DEE is the contract name
return this.DEE.deployed()
.then((instance) => instance.upload(this.inputs, {from: base.accounts[0]}))
.then((r) => {
this.message = "Transaction done"
console.log(r);
})
.catch((e) => {
console.error(e)
this.message = "Transaction failed"
})
但实际上，我发现 r 返回的是一个**交易明细**，比如，
{tx: "0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58",
receipt: {…}, logs: Array(0)}
logs
:
[]
receipt
:
{transactionHash: "0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58",
transactionIndex: 0, blockHash:
"0x07d691308724c73025de2f346dc0d6bc4eb7e7de9871e29ea2c4d4e8fb8222bb",
blockNumber: 20, gasUsed: 56460, …}
tx
:
"0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58"
proto
:
Object
没有关于应该返回的id的信息。
我是不是做错了什么？
在函数定义中指定"view"：
function upload(uint8[5] _inputs) public view returns ( bytes32 resultId) {
// do something here
// save ad calculate
return "123";
}
我想我找到了答案。
It is not currently possible to return values from functions which
modify the blockchain. To receive a return value, you can mark
read-only functions as "constant".
For non-constant functions, the only way to "return" information is by
using Solidity Events, which coalesce as LOG opcodes in the Ethereum
Virtual Machine.
我想写一个简单的函数来调用合约的方法并得到 运行 结果，
这是合约代码
function _evaluate(uint8[5] _uploads) internal returns (bytes32 resultId){
resultId= keccak256(abi.encodePacked(now, msg.sender));
addressToid[msg.sender] = resultId;
idToResult[resultId] = Result(msg.sender, r);
}
function upload(uint8[5] _inputs) public returns ( bytes32 resultId) {
return _evaluate(_inputs);
}
前端js代码
// DEE is the contract name
return this.DEE.deployed()
.then((instance) => instance.upload(this.inputs, {from: base.accounts[0]}))
.then((r) => {
this.message = "Transaction done"
console.log(r);
})
.catch((e) => {
console.error(e)
this.message = "Transaction failed"
})
但实际上，我发现 r 返回的是一个**交易明细**，比如，
{tx: "0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58",receipt: {…}, logs: Array(0)} logs : [] receipt : {transactionHash: "0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58", transactionIndex: 0, blockHash: "0x07d691308724c73025de2f346dc0d6bc4eb7e7de9871e29ea2c4d4e8fb8222bb", blockNumber: 20, gasUsed: 56460, …} tx : "0xa543fff3c3bac2268c0c94a21f6cf62faa8cf667defcd9fd8dcdbcf7669a4e58" proto : Object
没有关于应该返回的id的信息。
我是不是做错了什么？
在函数定义中指定"view"：
function upload(uint8[5] _inputs) public view returns ( bytes32 resultId) {
// do something here
// save ad calculate
return "123";
}
我想我找到了答案。
It is not currently possible to return values from functions which modify the blockchain. To receive a return value, you can mark read-only functions as "constant".
For non-constant functions, the only way to "return" information is by using Solidity Events, which coalesce as LOG opcodes in the Ethereum Virtual Machine.