PROSAGA码农传奇-以太坊-如何从以太坊区块链中检索数据

<div class =“post-text”itemprop =“text”>
  
    根据Web3 API文档，检索合同实例和调用方法的方法是：
  
  
    的
      1.合同定义
    </强>
  
   <pre>
 <code>
 var MyContract = web3.eth.contract(abi);

</code>
 </pre>
  
    的
      2.在地址获取合同实例
    </强>
  
   <pre>
 <code>
 var myContractInstance = MyContract .at('0x**********');

</code>
 </pre>
  
    的
      3.执行呼叫
    </强>
  
   <pre>
 <code>
 var owner = myContractInstance .owner.call();

</code>
 </pre>
  
    的
      完整代码：
    </强>
  
   <pre>
 <code>
 var abi = [
 {
 "constant": true,
 "inputs": [],
 "name": "owner",
 "outputs": [
 {
 "name": "",
 "type": "address"
 }
 ],
 "payable": false,
 "type": "function"
 },
 {
 "inputs": [],
 "payable": false,
 "type": "constructor"
 }
 ];

var MyContract = web3.eth.contract(abi);

// initiate contract for an address
var myContractInstance = MyContract .at('0xa07ddaff6d8b7aabf91ac6f82bf89455eb9784f4');

// call constant function (synchronous way)
var owner = myContractInstance .owner.call();

console.log("owner="+owner);

</code>
 </pre>
  
    的
      工作良好：
    </强>
  
   <pre>
 <code>
 owner=0x13a0674c16f6a5789bff26188c63422a764d9a39

</code>
 </pre>
</DIV>