如何将多个参数传递给指令？

I have a directive:

我有一个指令:

app.directive('testDir', [function () {
    return {
        require: '?ngModel',
        link: function ($scope, elm, attr, ngModel) {
            var abc=attr.testDir;
            var def=< The value zzz >
        }
    };
}])
app.directive('