停止jquery .on函数转向.off

Question

我有这个功能

$("#canvas").on("mousedown", handleMouseDown);

但是我不知道.off功能部件是如何工作的我已经使用了这个

$("#canvas").off("mousedown", handleMouseDown);

但似乎所有这一切都会阻止我的所有其他功能而不是那个功能。任何人都可以帮我这个功能

 square.addEventListener('click', function () {
        // Removed extra code

        $("#canvas").off("mousedown", handleMouseDown);
     context.fillStyle = color2;
        context.strokeStyle = color2;
        var putPoint2 = function (e) {
            if (dragging2) {
            var new_size = size/2;
                context.fillRect(e.offsetX-new_size, e.offsetY-new_size, size, size);
            }
        };
        engage2 = function (e) { // Made engage2() "global" to refer it in engage()
            dragging2 = true;
            putPoint2(e);
            canvas.addEventListener('mousemove', putPoint2); // Repositioned event attachment
            canvas.addEventListener('mouseup', disengage2); // Repositioned event attachment
        };
        var disengage2 = function () {
            dragging2 = false;
            context.beginPath();
            canvas.removeEventListener('mousemove', putPoint2); // Added event detachment
            canvas.removeEventListener('mouseup', disengage2); // Added event detachment
        };
        if (typeof engage === 'function') { // Added event detachment
            canvas.removeEventListener('mousedown', engage);
        }
        canvas.addEventListener('mousedown', engage2);
    });

使用.off事件时，此函数无法正常运行，而行函数仍然继续运行，这应该是关闭的位