1.基本方法
<script language="javascript" type="text/javascript">
function doSomething(callback) {
// …
// Call the callback
callback('stuff', 'goes', 'here');
}
function foo(a, b, c) {
// I'm the callback
alert(a + " " + b + " " + c);
}
doSomething(foo);
</script>
或者用匿名函数的形式
<script language="javascript" type="text/javascript">
function dosomething(damsg, callback){
alert(damsg);
if(typeof callback == "function")
callback();
}
dosomething("回调函数", function(){
alert("和 jQuery 的 callbacks 形式一样!");
});
</script>
2.高级方法
使用javascript的call方法
<script language="javascript" type="text/javascript">
function Thing(name) {
this.name = name;
}
Thing.prototype.doSomething = function(callback) {
// Call our callback, but using our own instance as the context
callback.call(this);
}
function foo() {
alert(this.name);
}
var t = new Thing('Joe');
t.doSomething(foo); // Alerts "Joe" via `foo`
</script>
传参数
<script language="javascript" type="text/javascript">
function Thing(name) {
this.name = name;
}
Thing.prototype.doSomething = function(callback, salutation) {
// Call our callback, but using our own instance as the context
callback.call(this, salutation);
}
function foo(salutation) {
alert(salutation + " " + this.name);
}
var t = new Thing('Joe');
t.doSomething(foo, 'Hi'); // Alerts "Hi Joe" via `foo`
</script>
使用 javascript 的 apply 传参数
<script language="javascript" type="text/javascript">
function Thing(name) {
this.name = name;
}
Thing.prototype.doSomething = function(callback) {
// Call our callback, but using our own instance as the context
callback.apply(this, ['Hi', 3, 2, 1]);
}
function foo(salutation, three, two, one) {
alert(salutation + " " + this.name + " – " + three + " " + two + " " + one);
}
var t = new Thing('Joe');
t.doSomething(foo); // Alerts "Hi Joe – 3 2 1" via `foo`
</script>
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