搭建第一个Dapp应用（3）——Solidity防伪溯源存证签证合约——2021.5.3

一丶配置：

1.运行环境:FISCO BCOS联盟链中间件——WeBASE-Front

2.合约语言：solidity 0.4.25版本

二丶合约代码

Evidence.sol

pragma solidity ^0.4.25;

contract EvidenceSignersDataABI
{
     
    //验证是否是合法地址
	function verify(address addr)public constant returns(bool){
     }
	//根据索引值返回签名者地址
	function getSigner(uint index)public constant returns(address){
     } 
	//返回签名人数
	function getSignersSize() public constant returns(uint){
     }
}

contract Evidence{
     
    
    string evidence; //存证信息
    address[] signers;//储存合法签名者地址
    address public factoryAddr;//工厂合约地址
    //返回事件信息，查看log->判断正确或错误的信息
    event addSignaturesEvent(string evi);
    event newSignaturesEvent(string evi, address addr);
    event errorNewSignaturesEvent(string evi, address addr);
    event errorAddSignaturesEvent(string evi, address addr);
    event addRepeatSignaturesEvent(string evi);
    event errorRepeatSignaturesEvent(string evi, address addr);
    //查看此地址是否为合法签名者地址
    function CallVerify(address addr) public constant returns(bool) {
     
        return EvidenceSignersDataABI(factoryAddr).verify(addr);
    }
    //初始化，创建存证合约
   constructor(string evi, address addr)  {
     
       factoryAddr = addr;
       //tx.origin =>启动交易的原始地址（其实就是部署者的地址）
       //如果是外部调用，在此可以理解为函数调用者地址
       if(CallVerify(tx.origin))
       {
     
           evidence = evi;
           signers.push(tx.origin);
           newSignaturesEvent(evi,addr);
       }
       else
       {
     
           errorNewSignaturesEvent(evi,addr);
       }
    }
    //返回签名信息，合约签名者地址，当前签名者地址
    function getEvidence() public constant returns(string,address[],address[]){
     
        uint length = EvidenceSignersDataABI(factoryAddr).getSignersSize();
         address[] memory signerList = new address[](length);
         for(uint i= 0 ;i<length ;i++)
         {
     
             signerList[i] = (EvidenceSignersDataABI(factoryAddr).getSigner(i));
         }
        return(evidence,signerList,signers);
    }
    //添加签名者地址（此地址必须为合约签名者地址）
    function addSignatures() public returns(bool) {
     
        for(uint i= 0 ;i<signers.length ;i++)
        {
     
            //此时的tx.orgin为当前调用此方法的调用者地址
            if(tx.origin == signers[i])
            {
     
                addRepeatSignaturesEvent(evidence);
                return true;
            }
        }
       if(CallVerify(tx.origin))
       {
     
            signers.push(tx.origin);
            addSignaturesEvent(evidence);
            return true;
       }
       else
       {
     
           errorAddSignaturesEvent(evidence,tx.origin);
           return false;
       }
    }
    //返回所有的合约签名者地址
    function getSigners()public constant returns(address[])
    {
     
         uint length = EvidenceSignersDataABI(factoryAddr).getSignersSize();
         address[] memory signerList = new address[](length);
         for(uint i= 0 ;i<length ;i++)
         {
     
             signerList[i] = (EvidenceSignersDataABI(factoryAddr).getSigner(i));
         }
         return signerList;
    }
}

EvidenceFactory

pragma solidity ^0.4.25;
import "Evidence.sol";

contract EvidenceFactory{
     
        address[] signers;  //存储签名者地址
		event newEvidenceEvent(address addr); //新签证事件，返回地址
		//传入签名内容 string类型，创建合约Evidence并初始化
        function newEvidence(string evi)public returns(address)
        {
     
            //this:代表当前工厂合约的地址
            Evidence evidence = new Evidence(evi, this);
            newEvidenceEvent(evidence);
            return evidence;
        }
        //获得签证信息
        function getEvidence(address addr) public constant returns(string,address[],address[]){
     
            return Evidence(addr).getEvidence();
        }
        
                
        function addSignatures(address addr) public returns(bool) {
     
            return Evidence(addr).addSignatures();
        }
        //初始化合约，导入签名者们的地址（数组传参）为合法签名者地址
        //只有合法签名者才有资格进行签证
        constructor(address[] evidenceSigners){
     
            for(uint i=0; i<evidenceSigners.length; ++i) {
     
            signers.push(evidenceSigners[i]);
			}
		}
        // 验证身份是否为合法签名者地址
        function verify(address addr)public constant returns(bool){
     
                for(uint i=0; i<signers.length; ++i) {
     
                if (addr == signers[i])
                {
     
                    return true;
                }
            }
            return false;
        }
        //根据索引值返回合约签名者地址
        function getSigner(uint index)public constant returns(address){
     
            uint listSize = signers.length;
            //判断索引值是否越界
            if(index < listSize)
            {
     
                return signers[index];
            }
            else
            {
     
                return 0;
            }
    
        }
        //获取当前合约签名者人数
        function getSignersSize() public constant returns(uint){
     
            return signers.length;
        }
        //返回所有合约签名者的地址
        function getSigners() public constant returns(address[]){
     
            return signers;
        }

}

三丶效果展示

1.部署合约，初始化传入2个用户地址

• 0x76c4e6e1d093092135d79677b724ae3470cdd6e3
• 0xad6110c4f698ec996667fd5e2da0cdf5f1ee78e8
  

2.查看合法签名者地址

3.查看是否为合法地址

4.创建签证合约（只有合法签名者才能成功创建）

5.查看签证信息

6.合法签名者签名签证合约

7.再次查看签证信息

四丶上一篇文章：搭建第一个Dapp应用（2）——搭建WeBase-Front中间件

搭建第一个Dapp应用（2）——搭建WeBase-Front中间件

五丶下一篇文章：搭建第一个Dapp应用（4）——搭建SmartDev-Scaffold

搭建第一个Dapp应用（4）——搭建SmartDev-Scaffold