javascript jQuery $(this) 内部函数
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jQuery $(this) inside function
提问by user1324762
I want to pass $(this) to function but I am not sure. There is one similar thread, but I still can not make it working. I hope somebody can help me.
我想将 $(this) 传递给函数，但我不确定。有一个类似的线程，但我仍然无法使其工作。我希望有人可以帮助我。
$(document).ready(function() {
var delay = (function(){
var timer = 0;
return function(callback, ms){
clearTimeout (timer);
timer = setTimeout(callback, ms);
};
})();
$('input').keyup(function() {
delay(function(){
alert($(this).val());
}, 1000 );
});
});
回答by Harmen
You should save a reference to this :
您应该保存对此的引用：
$('input').keyup(function() {
var $this = $(this);
delay(function(){
alert($this.val());
}, 1000 );
});
Another option is to re-bind thisto the function:
另一种选择是重新绑定this到函数：
$('input').keyup(function() {
delay(function(){
alert($(this).val());
}.bind(this), 1000 );
});
回答by David Hellsing
You would need to bring the context:
你需要带上上下文：
return function(callback, ms, context){
clearTimeout (timer);
timer = setTimeout(function() {
callback.call(context);
}, ms);
};
And then
接着
delay(function() {
alert($(this).val());
}, 1000, this );
But as others posted, saving the context in a local variable might be what you really want. Here is another way to do it:
但正如其他人发布的那样，将上下文保存在局部变量中可能是您真正想要的。这是另一种方法：
$('input').keyup(function() {
delay((function(self) {
return function() {
alert($(self).val());
};
}(this)), 1000);
});
回答by 0x499602D2
Keep a reference to $(this)outside the function.
保持$(this)对函数外部的引用。
// ...
$('input').keyup(function() {
var $this = $(this);
delay(function() {
alert( $this.val() );
}, 1000)
});
回答by James Kyburz
this changed because of function scope change. You need to store the value using a closure.
由于功能范围的变化，这发生了变化。您需要使用闭包存储该值。
If all you pass is the value you don't need $(this)
如果你传递的只是你不需要的值 $(this)
$('input').keyup(function() {
var val = this.value;
delay(function(){
alert(val);
}, 1000 );
});
Another way would be
另一种方式是
$('input').keyup(function() {
delay((function(val){
return function() {
alert(val);
};
}(this.value)), 1000 );
});
