OO Javascript-适当的范围处理？
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我已经写了一个简短且不完整的示例（出于这个问题），尝试使用jquery对一组图像的宽度求和。我在解决如何处理复杂的OO javascript应用程序中的范围时遇到了一些问题。
function imageContainer(){
this.selector = \"img.inContainer\";
this.width = function(){
var tmp = 0;
$(this.selector).each(function(){
// use load to preload images
$(this).load(function(){
// our \'this\' pointer to the original object is long gone,
// so is it even possible to accumulate a sum without using
// globals? Ideally, I\'d like to increment a temporary value
// that exists within the scope of this.width();
tmp+=$(this).width();
});
});
// I\'m thinking that returning here is problematic, because our
// call to each() may not be complete?
return tmp;
}
this.construct = function(){
alert(this.width());
}
this.construct();
}
没有找到相关结果
已邀请:
1 个回复
盛虱
function imageContainer() { this.selector = \"img.inContainer\"; this.width = function(cb) { var tmp = 0; var len = this.length; var count = 0; $(this.selector).each(function() { // use load to preload images var that = this; // load is ajax so it is async $(this).load(function() { tmp += $(that).width(); if (++count === len) { // counted all. cb(tmp); } }); }); }; this.construct = function(cb) { this.width(function(data) { alert(data); }); }; this.construct(); }模式，也可以改用。// load is ajax so it is async $(this).load($.proxy(function() { tmp += $(this).width(); if (++count === len) { // counted all. cb(tmp); } }, this));this.width = function(cb) { // map all images to deferred objects, when deferred objects are resolved $.when($.makeArray($(this.selector).map(function() { var def = $.Deferred(); $(this).load(function() { def.resolve(); }); return def; // then sum the widths and fire the callback. }))).then($.proxy(function(data) { var tmp = 0; $(this.selector).each(function() { tmp+=$(this).width(); }); cb(tmp); }, this)); };，但它不存在。可能是// reduce the set of images to the sum of their widths. cb($(this.selector).reduce(0, function(memo, key, val) { return memo + $(this).width(); }));