我使用JQuery这样:
$(window).resize(function() { ... });
但是,如果用户通过拖动窗口边缘来手动调整浏览器窗口的大小,上面的.resize事件会触发多次。
问题:如何在浏览器窗口调整大小完成后调用函数(使事件只触发一次)?
我使用JQuery这样:
$(window).resize(function() { ... });
但是,如果用户通过拖动窗口边缘来手动调整浏览器窗口的大小,上面的.resize事件会触发多次。
问题:如何在浏览器窗口调整大小完成后调用函数(使事件只触发一次)?
当前回答
如果你安装了Underscore.js,你可以:
$(window).resize(_.debounce(function(){
alert("Resized");
},500));
其他回答
假设鼠标光标在窗口调整大小后应该返回到文档,我们可以使用onmouseover事件创建一个类似回调的行为。不要忘记,这个解决方案可能不适用于预期的触摸屏。
var resizeTimer;
var resized = false;
$(window).resize(function() {
clearTimeout(resizeTimer);
resizeTimer = setTimeout(function() {
if(!resized) {
resized = true;
$(document).mouseover(function() {
resized = false;
// do something here
$(this).unbind("mouseover");
})
}
}, 500);
});
简单的jQuery插件延迟窗口调整事件。
语法:
增加了调整事件大小的新功能
jQuery(window).resizeDelayed( func, delay, id ); // delay and id are optional
删除之前添加的函数(通过声明其ID)
jQuery(window).resizeDelayed( false, id );
删除所有功能
jQuery(window).resizeDelayed( false );
用法:
// ADD SOME FUNCTIONS TO RESIZE EVENT
jQuery(window).resizeDelayed( function(){ console.log( 'first event - should run after 0.4 seconds'); }, 400, 'id-first-event' );
jQuery(window).resizeDelayed( function(){ console.log('second event - should run after 1.5 seconds'); }, 1500, 'id-second-event' );
jQuery(window).resizeDelayed( function(){ console.log( 'third event - should run after 3.0 seconds'); }, 3000, 'id-third-event' );
// LETS DELETE THE SECOND ONE
jQuery(window).resizeDelayed( false, 'id-second-event' );
// LETS ADD ONE WITH AUTOGENERATED ID(THIS COULDNT BE DELETED LATER) AND DEFAULT TIMEOUT (500ms)
jQuery(window).resizeDelayed( function(){ console.log('newest event - should run after 0.5 second'); } );
// LETS CALL RESIZE EVENT MANUALLY MULTIPLE TIMES (OR YOU CAN RESIZE YOUR BROWSER WINDOW) TO SEE WHAT WILL HAPPEN
jQuery(window).resize().resize().resize().resize().resize().resize().resize();
使用输出:
first event - should run after 0.4 seconds
newest event - should run after 0.5 second
third event - should run after 3.0 seconds
插件:
jQuery.fn.resizeDelayed = (function(){
// >>> THIS PART RUNS ONLY ONCE - RIGHT NOW
var rd_funcs = [], rd_counter = 1, foreachResizeFunction = function( func ){ for( var index in rd_funcs ) { func(index); } };
// REGISTER JQUERY RESIZE EVENT HANDLER
jQuery(window).resize(function() {
// SET/RESET TIMEOUT ON EACH REGISTERED FUNCTION
foreachResizeFunction(function(index){
// IF THIS FUNCTION IS MANUALLY DISABLED ( by calling jQuery(window).resizeDelayed(false, 'id') ),
// THEN JUST CONTINUE TO NEXT ONE
if( rd_funcs[index] === false )
return; // CONTINUE;
// IF setTimeout IS ALREADY SET, THAT MEANS THAT WE SHOULD RESET IT BECAUSE ITS CALLED BEFORE DURATION TIME EXPIRES
if( rd_funcs[index].timeout !== false )
clearTimeout( rd_funcs[index].timeout );
// SET NEW TIMEOUT BY RESPECTING DURATION TIME
rd_funcs[index].timeout = setTimeout( rd_funcs[index].func, rd_funcs[index].delay );
});
});
// <<< THIS PART RUNS ONLY ONCE - RIGHT NOW
// RETURN THE FUNCTION WHICH JQUERY SHOULD USE WHEN jQuery(window).resizeDelayed(...) IS CALLED
return function( func_or_false, delay_or_id, id ){
// FIRST PARAM SHOULD BE SET!
if( typeof func_or_false == "undefined" ){
console.log( 'jQuery(window).resizeDelayed(...) REQUIRES AT LEAST 1 PARAMETER!' );
return this; // RETURN JQUERY OBJECT
}
// SHOULD WE DELETE THE EXISTING FUNCTION(S) INSTEAD OF CREATING A NEW ONE?
if( func_or_false == false ){
// DELETE ALL REGISTERED FUNCTIONS?
if( typeof delay_or_id == "undefined" ){
// CLEAR ALL setTimeout's FIRST
foreachResizeFunction(function(index){
if( typeof rd_funcs[index] != "undefined" && rd_funcs[index].timeout !== false )
clearTimeout( rd_funcs[index].timeout );
});
rd_funcs = [];
return this; // RETURN JQUERY OBJECT
}
// DELETE ONLY THE FUNCTION WITH SPECIFIC ID?
else if( typeof rd_funcs[delay_or_id] != "undefined" ){
// CLEAR setTimeout FIRST
if( rd_funcs[delay_or_id].timeout !== false )
clearTimeout( rd_funcs[delay_or_id].timeout );
rd_funcs[delay_or_id] = false;
return this; // RETURN JQUERY OBJECT
}
}
// NOW, FIRST PARAM MUST BE THE FUNCTION
if( typeof func_or_false != "function" )
return this; // RETURN JQUERY OBJECT
// SET THE DEFAULT DELAY TIME IF ITS NOT ALREADY SET
if( typeof delay_or_id == "undefined" || isNaN(delay_or_id) )
delay_or_id = 500;
// SET THE DEFAULT ID IF ITS NOT ALREADY SET
if( typeof id == "undefined" )
id = rd_counter;
// ADD NEW FUNCTION TO RESIZE EVENT
rd_funcs[id] = {
func : func_or_false,
delay: delay_or_id,
timeout : false
};
rd_counter++;
return this; // RETURN JQUERY OBJECT
}
})();
非常感谢大卫沃尔什,这里是一个香草版本的下划线debounce。
代码:
// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
function debounce(func, wait, immediate) {
var timeout;
return function() {
var context = this, args = arguments;
var later = function() {
timeout = null;
if (!immediate) func.apply(context, args);
};
var callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) func.apply(context, args);
};
};
简单的用法:
var myEfficientFn = debounce(function() {
// All the taxing stuff you do
}, 250);
$(window).on('resize', myEfficientFn);
裁判:http://davidwalsh.name/javascript-debounce-function
前面提到的一些解决方案对我不起作用,尽管它们的用途更广泛。或者,我发现了这一个,在窗口大小调整的工作:
$(window).bind('resize', function(e){
window.resizeEvt;
$(window).resize(function(){
clearTimeout(window.resizeEvt);
window.resizeEvt = setTimeout(function(){
//code to do after window is resized
}, 250);
});
});
我喜欢创建一个事件:
$(window).bind('resizeEnd', function() {
//do something, window hasn't changed size in 500ms
});
下面是如何创建它:
$(window).resize(function() {
if(this.resizeTO) clearTimeout(this.resizeTO);
this.resizeTO = setTimeout(function() {
$(this).trigger('resizeEnd');
}, 500);
});
你可以把它放在某个全局javascript文件中。