web3.eth.abi¶

web3.eth.abi 函数用来解码及编码为 ABI (Application Binary Interface应用程序二进制接口) 以用于 EVM（以太坊虚拟机）进行函数调用。

encodeFunctionSignature¶

web3.eth.abi.encodeFunctionSignature(functionName);

将函数名称编码为其ABI签名，即函数名称（包括参数类型）的sha3哈希的前4个字节。

参数¶

functionName - String|Object: 需要编码的函数名字符串或者函数 JSON 接口对象。

如果是字符串，这形式需要是 function(type,type,...),例如： myFunction(uint256,uint32[],bytes10,bytes)

返回值¶

String - 函数的ABI签名。

示例¶

// 参数是 JSON 接口对象时
web3.eth.abi.encodeFunctionSignature({
    name: 'myMethod',
    type: 'function',
    inputs: [{
        type: 'uint256',
        name: 'myNumber'
    },{
        type: 'string',
        name: 'myString'
    }]
})
> 0x24ee0097

// 参数是字符串
web3.eth.abi.encodeFunctionSignature('myMethod(uint256,string)')
> '0x24ee0097'

encodeEventSignature¶

web3.eth.abi.encodeEventSignature(eventName);

将事件名称编码为其ABI签名，该签名是事件名称包括输入参数类型的sha3哈希。

参数¶

eventName - String|Object: 需要编码的事件名字符串或者事件 JSON 接口对象。

如果是字符串，这形式需要是 event(type,type,...)，如： myEvent(uint256,uint32[],bytes10,bytes)

返回值¶

String - 事件的ABI签名。

示例¶

web3.eth.abi.encodeEventSignature('myEvent(uint256,bytes32)')
> 0xf2eeb729e636a8cb783be044acf6b7b1e2c5863735b60d6daae84c366ee87d97

// 或者 ABI 接口对象形式
web3.eth.abi.encodeEventSignature({
    name: 'myEvent',
    type: 'event',
    inputs: [{
        type: 'uint256',
        name: 'myNumber'
    },{
        type: 'bytes32',
        name: 'myBytes'
    }]
})
> 0xf2eeb729e636a8cb783be044acf6b7b1e2c5863735b60d6daae84c366ee87d97

encodeParameter¶

web3.eth.abi.encodeParameter(type, parameter);

根据参数的类型将参数编码为其ABI表示形式。

参数¶

type - String|Object: 参数的类型，参考 solidity 文档查看类型列表。（译者注，Solidity 中文文档可以在`这里查看 <https://learnblockchain.cn/docs/solidity/types.html>`_ 。
parameter - Mixed: 要编码的实际参数。

返回值¶

String - ABI编码后的参数。

示例¶

web3.eth.abi.encodeParameter('uint256', '2345675643');
> "0x000000000000000000000000000000000000000000000000000000008bd02b7b"

web3.eth.abi.encodeParameter('uint256', '2345675643');
> "0x000000000000000000000000000000000000000000000000000000008bd02b7b"

web3.eth.abi.encodeParameter('bytes32', '0xdf3234');
> "0xdf32340000000000000000000000000000000000000000000000000000000000"

web3.eth.abi.encodeParameter('bytes', '0xdf3234');
> "0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003df32340000000000000000000000000000000000000000000000000000000000"

web3.eth.abi.encodeParameter('bytes32[]', ['0xdf3234', '0xfdfd']);
> "00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002df32340000000000000000000000000000000000000000000000000000000000fdfd000000000000000000000000000000000000000000000000000000000000"

web3.eth.abi.encodeParameter(
    {
        "ParentStruct": {
            "propertyOne": 'uint256',
            "propertyTwo": 'uint256',
            "childStruct": {
                "propertyOne": 'uint256',
                "propertyTwo": 'uint256'
            }
        }
    },
    {
        "propertyOne": 42,
        "propertyTwo": 56,
        "childStruct": {
            "propertyOne": 45,
            "propertyTwo": 78
        }
    }
);
> "0x000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000038000000000000000000000000000000000000000000000000000000000000002d000000000000000000000000000000000000000000000000000000000000004e"

encodeParameters¶

web3.eth.abi.encodeParameters(typesArray, parameters);

基于 JSON 接口对象编码函数参数。

参数¶

typesArray - Array<String|Object>|Object: 一个函数的类型的数组或者 JSON 接口。参考 solidity 文档查看类型列表。（译者注，Solidity 中文文档可以在`这里查看 <https://learnblockchain.cn/docs/solidity/types.html>`_ 。
parameters - Array: 需要编码的参数

返回值¶

String - ABI编码后的参数。

示例¶

web3.eth.abi.encodeParameters(['uint256','string'], ['2345675643', 'Hello!%']);
> "0x000000000000000000000000000000000000000000000000000000008bd02b7b0000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000748656c6c6f212500000000000000000000000000000000000000000000000000"

web3.eth.abi.encodeParameters(['uint8[]','bytes32'], [['34','434'], '0x324567fff']);
> "0x0

web3.eth.abi.encodeParameters(
    [
        'uint8[]',
        {
            "ParentStruct": {
                "propertyOne": 'uint256',
                "propertyTwo": 'uint256',
                "ChildStruct": {
                    "propertyOne": 'uint256',
                    "propertyTwo": 'uint256'
                }
            }
        }
    ],
    [
        ['34','434'],
        {
            "propertyOne": '42',
            "propertyTwo": '56',
            "ChildStruct": {
                "propertyOne": '45',
                "propertyTwo": '78'
            }
        }
    ]
);
> "0x00000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000038000000000000000000000000000000000000000000000000000000000000002d000000000000000000000000000000000000000000000000000000000000004e0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000018"

encodeFunctionCall¶

web3.eth.abi.encodeFunctionCall(jsonInterface, parameters);

用 JSON 接口及给定的参数编码函数调用

参数¶

jsonInterface - Object: 函数的 JSON 接口对象
parameters - Array: 需要编码的参数

返回值¶

String - ABI编码的函数调用。表示为函数签名+参数。

示例¶

web3.eth.abi.encodeFunctionCall({
    name: 'myMethod',
    type: 'function',
    inputs: [{
        type: 'uint256',
        name: 'myNumber'
    },{
        type: 'string',
        name: 'myString'
    }]
}, ['2345675643', 'Hello!%']);
> "0x24ee0097000000000000000000000000000000000000000000000000000000008bd02b7b0000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000748656c6c6f212500000000000000000000000000000000000000000000000000"

decodeParameter¶

web3.eth.abi.decodeParameter(type, hexString);

将ABI编码参数解码为其对应的JavaScript类型。

参数¶

type - String|Object: 参数的类型, 参考 solidity 文档查看类型列表。（译者注，Solidity 中文文档可以在`这里查看 <https://learnblockchain.cn/docs/solidity/types.html>`_ 。
hexString - String: 要解码的ABI字节码。

返回值¶

Mixed - 解码后的参数。

示例¶

web3.eth.abi.decodeParameter('uint256', '0x0000000000000000000000000000000000000000000000000000000000000010');
> "16"

web3.eth.abi.decodeParameter('string', '0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000848656c6c6f212521000000000000000000000000000000000000000000000000');
> "Hello!%!"

web3.eth.abi.decodeParameter('string', '0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000848656c6c6f212521000000000000000000000000000000000000000000000000');
> "Hello!%!"

web3.eth.abi.decodeParameter(
    {
        "ParentStruct": {
          "propertyOne": 'uint256',
          "propertyTwo": 'uint256',
          "childStruct": {
            "propertyOne": 'uint256',
            "propertyTwo": 'uint256'
          }
        }
    },

, '0x000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000038000000000000000000000000000000000000000000000000000000000000002d000000000000000000000000000000000000000000000000000000000000004e');
> {
    '0': {
        '0': '42',
        '1': '56',
        '2': {
            '0': '45',
            '1': '78',
            'propertyOne': '45',
            'propertyTwo': '78'
        },
        'childStruct': {
            '0': '45',
            '1': '78',
            'propertyOne': '45',
            'propertyTwo': '78'
        },
        'propertyOne': '42',
        'propertyTwo': '56'
    },
    'ParentStruct': {
        '0': '42',
        '1': '56',
        '2': {
            '0': '45',
            '1': '78',
            'propertyOne': '45',
            'propertyTwo': '78'
        },
        'childStruct': {
            '0': '45',
            '1': '78',
            'propertyOne': '45',
            'propertyTwo': '78'
        },
        'propertyOne': '42',
        'propertyTwo': '56'
    }
}

decodeParameters¶

web3.eth.abi.decodeParameters(typesArray, hexString);

将ABI编码参数解码为其对应JavaScript类型。

参数¶

typesArray - Array<String|Object>|Object: 类型数组或者:ref:JSON 接口 <glossary-json-interface> 输出数组。参考 solidity 文档查看类型列表。（译者注，Solidity 中文文档可以在`这里查看 <https://learnblockchain.cn/docs/solidity/types.html>`_ 。
hexString - String: 要解码的ABI字节码。

返回值¶

Object - 已解码参数的结果对象。

示例¶

web3.eth.abi.decodeParameters(['string', 'uint256'], '0x000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000ea000000000000000000000000000000000000000000000000000000000000000848656c6c6f212521000000000000000000000000000000000000000000000000');
> Result { '0': 'Hello!%!', '1': '234' }

web3.eth.abi.decodeParameters([{
    type: 'string',
    name: 'myString'
},{
    type: 'uint256',
    name: 'myNumber'
}], '0x000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000ea000000000000000000000000000000000000000000000000000000000000000848656c6c6f212521000000000000000000000000000000000000000000000000');
> Result {
    '0': 'Hello!%!',
    '1': '234',
    myString: 'Hello!%!',
    myNumber: '234'
}

web3.eth.abi.decodeParameters([
  'uint8[]',
  {
    "ParentStruct": {
      "propertyOne": 'uint256',
      "propertyTwo": 'uint256',
      "childStruct": {
        "propertyOne": 'uint256',
        "propertyTwo": 'uint256'
      }
    }
  }
], '0x00000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000038000000000000000000000000000000000000000000000000000000000000002d000000000000000000000000000000000000000000000000000000000000004e0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000002a0000000000000000000000000000000000000000000000000000000000000018');
> Result {
    '0': ['42', '24'],
    '1': {
        '0': '42',
        '1': '56',
        '2':
            {
                '0': '45',
                '1': '78',
                'propertyOne': '45',
                'propertyTwo': '78'
            },
        'childStruct':
            {
                '0': '45',
                '1': '78',
                'propertyOne': '45',
                'propertyTwo': '78'
            },
        'propertyOne': '42',
        'propertyTwo': '56'
    }
}

decodeLog¶

web3.eth.abi.decodeLog(inputs, hexString, topics);

解码ABI编码的日志数据和索引主题数据。

参数¶

inputs - Object: JSON 接口输入数组. 参考 solidity 文档查看类型列表。（译者注，Solidity 中文文档可以在`这里查看 <https://learnblockchain.cn/docs/solidity/types.html>`_ 。
hexString - String: 日志的 data 字段中的 ABI 字节码。
topics - Array: 日志中带有索引主题参数的数组，如果为非匿名事件，则不包含topic[0]，否则包含topic[0]。

返回值¶

Object - 包含已解码参数的结果对象。

示例¶

web3.eth.abi.decodeLog([{
    type: 'string',
    name: 'myString'
},{
    type: 'uint256',
    name: 'myNumber',
    indexed: true
},{
    type: 'uint8',
    name: 'mySmallNumber',
    indexed: true
}],
'0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000748656c6c6f252100000000000000000000000000000000000000000000000000',
['0x000000000000000000000000000000000000000000000000000000000000f310', '0x0000000000000000000000000000000000000000000000000000000000000010']);
> Result {
    '0': 'Hello%!',
    '1': '62224',
    '2': '16',
    myString: 'Hello%!',
    myNumber: '62224',
    mySmallNumber: '16'
}