訪問父母的財產

Question

您好我需要改變鼠標移動財產的OnMouseMove但我不能訪問MYFUNC對象，因爲這指EL沒有父！

function myfunc (el) { 
    this.el = el; 
    this.mousemove = false; 

    el.onmousemove = function(){ 
     this.mousemove = true; 
    }; 
} 

Answer 1

只要存儲對this的引用，就可以隨意調用它。這是常見的使用that或self：

function myfunc(el) { 
    var that; 
    that = this; 
    this.el = el; 
    this.mousemove = false; 
    el.mousemove = function() { 
    that.mousemove = true; 
    }; 
} 

Answer 2

一種方法是創建相關this參考;例如

function myfunc (el) { 
    this.el = el; 
    this.mousemove = false; 

    var t=this; 
    el.onmousemove = function(){ 
     t.mousemove = true; 
    }; 
} 

Answer 3

取出this的，因爲它們都指牛逼window

function myfunc (el) { 
    var mousemove = false; //scoped 

    el.onmousemove = function(){ 
     mousemove = true; //same scoped variable 
    }; 
} 

Answer 4

這聽起來像你想的mousemove值從onmousemove處理程序發生改變。如果是這樣，則需要將原始上下文捕獲到您稍後可以訪問的值中。例如

function myfunc (el) { 
    this.el = el; 
    this.mousemove = false; 
    var self = this; 

    el.onmousemove = function(){ 
     self.mousemove = true; 
    }; 
}