javascript:在jcanvas的draw方法中从事件侦听器访问父对象
我正在使用jcanvas()来学习javascript项目。我有以下代码:javascript:在jcanvas的draw方法中从事件侦听器访问父对象,javascript,jquery,jcanvas,Javascript,Jquery,Jcanvas,我正在使用jcanvas()来学习javascript项目。我有以下代码: var Board = function($element){ this.place_piece = function(piece){ this.board[piece.position[0]][piece.position[1]] = piece; $element.drawImage({ source: piece.image,
var Board = function($element){
this.place_piece = function(piece){
this.board[piece.position[0]][piece.position[1]] = piece;
$element.drawImage({
source: piece.image,
draggable: true,
layer: true,
x: this.get_coordinates_by_cell(piece.position)[0],
y: this.get_coordinates_by_cell(piece.position)[1],
dragstop: function(layer){
console.log($this)
console.log(layer)
}
});
}
我需要访问dragstop函数中的父Board对象的方法。但是当我在那里调用$this变量时,我得到了canvas。。。不是董事会本身。有什么事要做吗 进入电路板构造函数时,将其分配给局部变量(self),以便在同一范围内定义的其他函数可以访问它 类似于以下的方法将起作用:
var Board = function($element){
var self = this;
this.place_piece = function(piece){
this.board[piece.position[0]][piece.position[1]] = piece;
$element.drawImage({
source: piece.image,
draggable: true,
layer: true,
x: this.get_coordinates_by_cell(piece.position)[0],
y: this.get_coordinates_by_cell(piece.position)[1],
dragstop: function(layer){
console.log(self)
console.log($this)
console.log(layer)
}
});
}