准备三步曲

这一节我们要讲的是智能合约前期的准备工作。

本地环境

本地环境部署这个就不在多说本论坛已经有很多的教程，这里列出链接：
eos本地环境部署
 在MacOS和Ubuntu上搭建EOS V2.0 ---爬过好多坑后的总结
除了部署本地环境以外，你还需要以下额外的操作：

cd build 

make install

编译完以后就可以使用eos的插件了：eosc/eos-wallet/eoscpp/eosd
eosd: 用来开启本地测试网络。
eosc: eos的命令行接口。
eoscpp: eos智能合约相关的功能，生成模版智能合约等等。
eos-wallet: eos钱包功能。

账户

新建一个或多个账户，部署智能合约，测试智能合约都能用得到。
本论坛有关账户的创建教程已经很完善，例如：
对eos的wallet和account简单关系的个人理解

基础文件生成

利用eoscpp可以快速的生成模版智能合约：

eoscpp -n <contract name>

执行完以后会在本地生成一个contract name的文件夹，里面包含智能合约需要的基础文件。执行截图如下：会生成.cpp/.abi/.hpp三个必要的文件,文件中包含生成智能合约的基本内容。

开始三步曲

准备工作完成以后，开始写智能合约。

结构编写

/**

 *  @file

 *  @copyright defined in eos/LICENSE.txt

 */

#include <eoslib/eos.hpp>

#include <eoslib/db.hpp>



using namespace eosio; //使用eosio命名空间



namespace eos_fans{

        //数据库

    struct PACKED(love) {

        account_name    lover; //被表白的人

        account_name    author; //表白的人

        uint8_t                     times; //表白次数

    };



    //对谁表白action

    struct say {

        account_name    lover; //被表白的人

        account_name    author; //表白的人



    };



//table 参数依次为：该表所在的默认帐户名范围，代码帐户名称具有对此表的写入权限，表名，存储在每一行中的数据类型， 记录中存储的第一个字段的类型。

    using Lovers = eosio::table<N(eosfans),N(eosfans),N(loves),love,uint64_t>; 

}

逻辑.cpp

#include <eosfans.hpp>



using namespace eosio;



namespace eos_fans{

    //代码逻辑

    void say_love(const say& s) {

          //判断用户权限

        require_auth(s.author);

        love exited_love;

        bool love_exiting = Lovers::get(s.lover, exited_love, s.author);

          //判断是否已经存在，如果存在times加1，如果不存在则创建数据。

        if (love_exiting == true){

            exited_love.times += 1;

            Lovers::update(exited_love, s.author);



        }else{

            love love_to_say;

            love_to_say.lover = s.lover;

            love_to_say.author = s.author;

            love_to_say.times = 1;

            Lovers::store(love_to_say, s.author);

        }

    }

}



extern "C" {

    void init() {



    }



    /// The apply method implements the dispatch of events to this contract

    void apply( uint64_t code, uint64_t action ) {

        if ( code == N(eosfans) ){

            if (action == N(say)){

                eos_fans::say_love(current_message<eos_fans::say>());

            }

    }

}

}// extern "C"

abi编写

abi文件根据官网描述是可以通过eoscpp自动生成的，但是笔者尝试过，生成的文件的各个字段都是空的，所以这里就需要笔者自己编写，当然如果有人生成成功，可以告诉笔者正确生成方法，在这里提前感谢。
abi文件内容如下：

{

  "types": [],

  "structs": [{

        "name": "love", //所存储的数据类型

        "base": "",

        "fields": {

            "lover": "account_name",

            "author": "account_name",

            "times": "uint8"

        }

  },{

        "name": "say", //action

        "base": "",

        "fields": {

            "lover": "account_name",

            "author": "account_name"

        }

  }],

  "actions": [{

        "action_name": "say",

        "type": "say"

  }],

  "tables": [{

        "table_name": "loves", //数据表

        "type": "love",

        "index_type": "i64",

        "key_names": ["lover"], //索引字段

        "key_types": ["account_name"]

  }]

}

成功三步曲

智能合约写完以后，成功就近在眼前了。

智能合约文件生成

智能合约的各个组件编写完毕以后，下一步就是编译成.wast文件，eos有专门的工具：eoscpp，执行命令如下：

eoscpp -g eosfans.wast eosfans.cpp

执行完以后如果没有报错，就说明智能合约文件生成完毕，如果有错误可以根据错误对智能合约进行更改。

智能合约发布

智能合约文件生成完以后我们就要发布智能合约，命令如下：

eosc set contract eosfans eosfans.wast eosfans.abi

执行完以后你会看到智能合约生成的交易：

Reading WAST...

Assembling WASM...

Publishing contract...

{

  "transaction_id": "e59fac3876441bce2e65c6d20294523f6e597af71e0e7699b2d6d436a6f24444",

  "processed": {

    "ref_block_num": 64936,

    "ref_block_prefix": 4035039255,

    "expiration": "2018-03-03T07:59:50",

    "scope": [

      "eos",

      "lome"

    ],

    "signatures": [

      "1f030f69ef5e5f3c3f90835c04cd5ee9756a78ba22f7227ffee88dd33d3bc138450dd1e8caceb3c11bfe318389f772593f53f6103316d0c1650b514aab680a2c8d"

    ],

    "messages": [{

        "code": "eos",

        "type": "setcode",

        "authorization": [{

            "account": "lome",

            "permission": "active"

          }

        ],

        "data": {

          "account": "lome",

          "vm_type": 0,

          "vm_version": 0,

          "code": "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",

          "code_abi": {

            "types": [],

            "structs": [{

                "name": "love",

                "base": "",

                "fields": {

                  "lover": "account_name",

                  "author": "account_name",

                  "times": "uint8"

                }

              },{

                "name": "say",

                "base": "",

                "fields": {

                  "lover": "account_name",

                  "author": "account_name"

                }

              }

            ],

            "actions": [{

                "action_name": "say",

                "type": "say"

              }

            ],

            "tables": [{

                "table_name": "loves",

                "index_type": "i64",

                "key_names": [

                  "lover"

                ],

                "key_types": [

                  "account_name"

                ],

                "type": "love"

              }

            ]

          }

        },

        "hex_data": "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"

      }

    ],

    "output": [{

        "notify": [],

        "deferred_trxs": []

      }

    ]

  }

}

现在我们可以来看一下我们智能合约的table内容，通过如下命令察看：

eosc get table eosfans eosfans loves //table拥有者，智能合约名称， table名称

我们可以看到如下的显示：

智能合约使用

根据abi文件我们可以轻松使用智能合约，命令如下：

eosc push message eosfans say '{"lover": "eosfans", "author": "lome2"}' -S lome2 -p lome2@active

执行完以后我们可以看到交易的详情：现在我们来看一下执行完几次后笔者的数据表，如下所示：

该智能合约我已经发布在测试网络，合约名称为eosfans欢迎各位一起玩。

说明： 最近一直在学习智能合约其中遇到很多困难，譬如本地用的是2.0,官网的接口文档是3.0。这次使用的是2.0，以后将会把本地版本部署为3.0，这片文章以后若是在未说明的情况下所用的版本都为3.0。

有部分图片没有显示，这里就不在加了。

原文转自：https://eosfans.xyz/t/lover-wall-wo-de-di-yi-ge-bao-han-shu-ju-ku-de-jian-dan-de-zhi-neng-he-yue-yuan-chuang/62/