如何在AngularJS指令中传递变量值？

app.directive('myDirective', function() {
  return {
    scope: {
      myVariable: '='
    },
    template: '<div>{{ myVariable }}</div>'
  };
});

<my-directive my-variable="myValue"></my-directive>

app.directive('myDirective', function() {
  return {
    scope: {
      myVariable: '@'
    },
    template: '<div>{{ myVariable }}</div>'
  };
});

<my-directive my-variable="myValue"></my-directive>

app.directive('myDirective', function() {
  return {
    scope: {
      myFunction: '&'
    },
    template: '<button ng-click="myFunction()">Click me</button>'
  };
});

<my-directive my-function="myFunction"></my-directive>