Solidity payable函数交易回退错误：如何正确设置Producer完成账户间交易？

问题原因 #

你的交易回退核心原因是PurchaseFeature1函数中的require(Producer == msg.sender)校验失败：

• 合约中仅声明了address payable Producer变量，没有任何赋值逻辑，该变量默认值为0x0000000000000000000000000000000000000000
• 你用Producer账户调用函数时，msg.sender是你的Producer账户地址，和默认的0地址不匹配，触发校验失败导致交易回退，Remix返回的是通用回退报错信息。

修复方案 #

1. 新增Producer地址设置函数 #

在合约中添加仅Supplier可调用的Producer地址配置函数，完整代码如下：

pragma solidity ^0.5.0; 

contract supply {
    address payable Supplier;
    address payable Producer;
    uint constant payment_unit = 1 ether;
    uint public price_feature1_wei = 0;
    string public features_product1;
    bool public SellSuplier = true;
    bool public contract_terminated = false;

    constructor () public payable {
        Supplier = msg.sender;
        features_product1 = "product description...";
    }

    // 新增：仅供应商可设置允许采购的生产商地址
    function setProducer(address payable _producer) public {
        require(msg.sender == Supplier, "No permission");
        Producer = _producer;
    }

    function PriceFeature1 (uint amount) public {
        require (SellSuplier == true);
        require (Supplier == msg.sender);
        price_feature1_wei = amount * payment_unit;
    }

    function PurchaseFeature1() public payable {
        require (price_feature1_wei > 0);
        require (msg.value == price_feature1_wei);
        require (SellSuplier == true);
        require (Producer == msg.sender);
        require (Supplier.send(msg.value));
        SellSuplier = false;
    }
}

2. 调整操作流程 #

修改后的操作步骤如下：

• 部署合约，Supplier账户调用PriceFeature1传入1设置商品价格（和原有操作一致）
• 保持当前账户为Supplier，调用setProducer函数，入参填你用来作为Producer的Remix账户地址
• 切换Remix账户为Producer，value字段填1 ether，调用PurchaseFeature1函数即可完成交易

注意事项 #

如果后续Supplier地址为合约账户而非普通外部账户，send函数2300gas的限制可能导致转账失败，可将require (Supplier.send(msg.value))替换为Supplier.transfer(msg.value)获得更明确的报错，或升级solidity版本使用call进行转账。

内容的提问来源于stack exchange，提问作者LuCast