const { windowWidth, windowHeight } = wx.getSystemInfoSync()
function drawRect(x, y) {
  context.clearRect(0, 0, windowWidth, windowHeight)
  context.fillRect(x, y, 100, 100)
}
drawRect(canvas.width / 2 - 50, 0)

文档中，绘制下落矩形时每一帧都clearRect，后面加载飞机图片，飞机图片不显示，拖动飞机图片时闪烁显示

const image = wx.createImage()
const imgX = canvas.width / 2 - 50
let imgY = 500
image.onload = function () {
  context.drawImage(image, imgX, imgY)
}
image.src = 'img/plane.png'

是我代码位置写的不对吗？

以下是我的代码，完全按文档写的

const canvas = wx.createCanvas();

const context = canvas.getContext('2d');

const {

windowWidth,

windowHeight

} = wx.getSystemInfoSync();

context.fillStyle = '#1AAD19';

const rectX = canvas.width / 2 - 50;

let rectY = 0;

setInterval(function() {

drawRect(rectX, rectY++);

}, 16);

const image = wx.createImage();

image.src = 'images/plane.png';

const imgX = canvas.width / 2 - 50;

let imgY = 500;

image.onload = function() {

context.drawImage(image, imgX, imgY)

}

// 存储当前飞机左上角坐标

let touchX = imgX

let touchY = imgY

wx.onTouchMove(function(res) {

context.clearRect(touchX, touchY, 100, 100); // 清除画布上原有的飞机

touchX = res.changedTouches[0].clientX // 重新判断当前触摸点x坐标

touchY = res.changedTouches[0].clientY // 重新判断当前触摸点x坐标

context.drawImage(image, touchX, touchY);

if (touchX >= rectX - 100 && touchX <= rectX + 100 && touchY >= rectY - 100 && touchY <= rectY + 100) { // 飞机与矩形发生碰撞

wx.showModal({

title: '提示',

content: '发生碰撞，游戏结束！'

})

}

})

function drawRect(x, y) {

context.clearRect(0, 0, windowWidth, windowHeight);

context.fillRect(x, y, 100, 100);

}