DAPP is a decentralized application that is built on blockchain technology and has the characteristics of decentralization, openness, transparency, security, etc. DAPP can achieve various functions, such as digital currency wallets, decentralized exchanges, decentralized social networks, etc.
Dapp is the abbreviation for decentralized applications. It is an application built on blockchain technology, with characteristics such as decentralization, openness, transparency, security, and stability. Unlike traditional applications, DAPP does not require the use of traditional servers and databases, but rather runs directly on the blockchain.
The development and operation of DAPP is based on smart contracts, which are an automatically executed contract running on the blockchain. It can achieve automated transaction and management logic, and automatically supervise and execute according to set rules. Dapp achieves decentralized data storage, business logic, and value exchange through smart contracts.
The technical architecture of dapp mainly includes the following three levels:
Application layer: The application layer refers to the DAPP application that users directly come into contact with, including interface design, interaction methods, user experience, etc., which needs to fully consider user needs and usage habits.
Protocol layer: The protocol layer refers to the protocols and rules of DAPP, including communication protocols, transaction rules, financial protocols, contract protocols, etc., which need to ensure their security, stability, and transparency.
Blockchain layer: The blockchain layer is the underlying technical support for DAPP, including blockchain nodes, smart contracts, decentralized storage, consensus algorithms, etc. It requires algorithms and technical means to achieve decentralization, security, and scalability.
智能合约代码如下：
pragma solidity^0.4.0;
contract Ballot{
struct Voter{
uint weight;
bool voted;
address delegate;
uint vote;
}
struct Proposal{
uint voteCount;
}
address public chairperson;
mapping(address=>Voter)public voters;
Proposal[]public proposals;
function Ballot(uint8 _numProposals)public{
chairperson=msg.sender;
voters[chairperson].weight=1;
proposals.length=_numProposals;
}
function register(address toVoter)public{
if(msg.sender!=chairperson||voters[toVoter].voted)return;
voters[toVoter].weight=1;
voters[toVoter].voted=false;
voters[toVoter].delegate=address(0);
voters[toVoter].vote=uint(0);
}
function delegate(address to)public{
Voter storage sender=voters[msg.sender];//assigns reference
if(sender.voted)return;
while(voters[to].delegate!=address(0)&&voters[to].delegate!=msg.sender)
to=voters[to].delegate;
if(to==msg.sender)return;
sender.voted=true;
sender.delegate=to;
Voter storage delegateTo=voters[to];
if(delegateTo.voted)
proposals[delegateTo.vote].voteCount+=sender.weight;
else
delegateTo.weight+=sender.weight;
}
function vote(uint toProposal)public{
Voter storage sender=voters[msg.sender];
if(sender.voted||toProposal>=proposals.length)return;
sender.voted=true;
sender.vote=toProposal;
proposals[toProposal].voteCount+=sender.weight;
}
function winningProposal()public constant returns(uint winningProposal_){
uint winningVoteCount=0;
for(uint prop=0;prop<proposals.length;prop++)
if(proposals[prop].voteCount>winningVoteCount){
winningVoteCount=proposals[prop].voteCount;
winningProposal_=prop;
}
}
}
