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Ethereum Solidity Payable Method Demo
import "./SafeMath.sol";
contract Constants {
uint8 public constant BUY_ID = 1;
uint8 public constant SUBSCRIBE_ID = 2;
}
contract BuyContract is Constants {
uint256 public lastAmount;
function buyMethod(uint8 _buyArg) payable public {
require(_buyArg == BUY_ID);
lastAmount = msg.value;
}
}
contract SubscribeContract is Constants {
uint256 public lastAmount;
function subscribeMethod(uint8 _subscribeArg) payable public {
require(_subscribeArg == SUBSCRIBE_ID);
lastAmount = msg.value;
}
}
contract MyContract is Constants {
using SafeMath for uint256;
function singleTransaction(
address _buyAddress,
address _subscribeAddress
) payable public {
BuyContract buyContract = BuyContract(_buyAddress);
SubscribeContract subContract = SubscribeContract(_subscribeAddress);
uint256 halfValue = msg.value.div(2);
buyContract.buyMethod.value(halfValue)(BUY_ID);
subContract.subscribeMethod.value(halfValue)(SUBSCRIBE_ID);
}
}
pragma solidity ^0.5.2;
/**
* @title SafeMath
* @dev Unsigned math operations with safety checks that revert on error
*/
library SafeMath {
/**
* @dev Multiplies two unsigned integers, reverts on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b);
return c;
}
/**
* @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a);
uint256 c = a - b;
return c;
}
/**
* @dev Adds two unsigned integers, reverts on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a);
return c;
}
/**
* @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
* reverts when dividing by zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b != 0);
return a % b;
}
}
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