... virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
}
````
先执行了_transfer函数后执行_checkOnERC721Received函数,而后者是为了检测to这个参数是否...
你好!
我写了一个合约 是转erc20_usdt的,现在用remix_javascript vm调用 approveofUsdt 来授权。授权完了,再执行我合约写的转账方法pledgeUsdt,无法把代币转走。报错:The called function should be payable if you send value and the value you send should b...