Javascript 我试图在鼠标滑过和滑出时更改drawImage

我正在尝试这样做，这样当鼠标在var play设置的边界内时，它就会改变图像。我使用了与单击时更改图像相同的方法，但是mouseover和mouseout不想在这里工作

var play = {
    x: 650,
    y: 360,
    width: 200,
    height: 100
}
var playUpButton = new Image();
playUpButton.src = "images/PlayUp.png";
var playDownButton = new Image();
playDownButton.src = "images/PlayDown.png";
var playHovering = false;

thisCanvas.addEventListener('click', checkPlay);
thisCanvas.addEventListener('mouseover', hoverPlay, false);
thisCanvas.addEventListener('mouseout', hoverPlay, false);

function seen_move(e)
{
    var bounding_box = thisCanvas.getBoundingClientRect();
    mouseX = ((e.clientX-bounding_box.left) *(thisCanvas.width/bounding_box.width));
    mouseY = ((e.clientY-bounding_box.top) * (thisCanvas.height/bounding_box.height));
}

function draw_start()
{
    context.drawImage(menubg, menubg.x, menubg.y, menubg.width, menubg.height);
    if(playHovering)
    {
        context.drawImage(playDownButton, play.x, play.y, play.width, play.height);
    }
}


function mouseInArea(top, right, bottom, left)
{
    if(mouseX >= left && mouseX < right && mouseY >= top && mouseY < bottom)
    {
        return true;
    }
    else
    {
        return false;
    }
}   

function hoverPlay()
{
    if(mouseInArea(play.y, play.x + play.width, play.y + play.height, play.x))
    {
        console.log("Hovering");
        if(playHovering)
        {
            playHovering = false;
        }
        else
        {
            playHovering = true;
        }
    }
}

---

您的代码中似乎缺少以下内容

var thisCanvas = document.getElementById("thisCanvas"); 

功能checkPlay似乎也丢失了

请看这些文章：

您必须调用函数seen\u movee来获取鼠标位置

顺便说一句，我不知道seen_move中的额外代码是什么。我猜您正在创建鼠标相对于边界框的位置。我只是提一下，以防这也是一个问题：

// this usually get the mouse position
var bounding_box = thisCanvas.getBoundingClientRect();
mouseX = e.clientX-bounding_box.left;
mouseY = e.clientY-bounding_box.top;

// and you have this extra bit:
// *(thisCanvas.width/bounding_box.width)); and 
// * (thisCanvas.height/bounding_box.height));
mouseX = ((e.clientX-bounding_box.left) *(thisCanvas.width/bounding_box.width));
mouseY = ((e.clientY-bounding_box.top) * (thisCanvas.height/bounding_box.height));

---

我没有添加所有代码。很抱歉造成混淆，这两个东西都存在。请在hoverPlay函数中添加一些console.log语句。没有所有的代码很难判断，但是seed_move函数可能永远不会被调用。