您可以设置变量，例如:

You can set a variable, for example:

var alreadySent = false;

然后在您的ajax回调函数中将其更改为true(假设您使用的是jQuery post):

then in your ajax callback function you can change it to true (assuming you are using jQuery post):

if (!alreadySent) {
  $.post("address", params, function(data) {
    // do something
    alreadySent = true;
  });
}