Egret5.2.2 微信小游戏行的示例排行榜

/**
* 微信开放数据域
* 使用 Canvas2DAPI 在 SharedCanvas 渲染一个排行榜，
* 并在主域中渲染此 SharedCanvas
*//**
* 资源加载组，将所需资源地址以及引用名进行注册
* 之后可通过assets.引用名方式进行获取
*/
var assets = {
icon: "openDataContext/assets/icon.png",
box: "openDataContext/assets/box.png",
panel: "openDataContext/assets/panel.png",
button: "openDataContext/assets/button.png",
title: "openDataContext/assets/rankingtitle.png"
};
/**
* canvas 大小
* 这里暂时写死
* 需要从主域传入
*/
let canvasWidth;
let canvasHeight;/**
* 加载资源函数
* 理论上只需要加载一次，且在点击时才开始加载
* 最好与canvasWidht和canvasHeight数据的传入之后进行
*/
preloadAssets();//获取canvas渲染上下文
var context = sharedCanvas.getContext("2d");
context.globalCompositeOperation = "source-over";/**
* 所有头像数据
* 包括姓名，头像图片，得分
* 排位序号i会根据parge*perPageNum+i+1进行计算
*/
let totalGroup = [
{ key: 1, name: "1111111111", url: assets.icon, scroes: 10000 },
{ key: 2, name: "2222222222", url: assets.icon, scroes: 9000 },
{ key: 3, name: "3333333", url: assets.icon, scroes: 8000 },
{ key: 4, name: "4444444", url: assets.icon, scroes: 7000 },
{ key: 5, name: "55555555", url: assets.icon, scroes: 6000 },
{ key: 6, name: "6666666", url: assets.icon, scroes: 5000 },
{ key: 7, name: "7777777", url: assets.icon, scroes: 4000 },
{ key: 8, name: "8888888", url: assets.icon, scroes: 3000 },
{ key: 9, name: "9999999", url: assets.icon, scroes: 2000 },
{ key: 10, name: "1010101010", url: assets.icon, scroes: 2000 },
{ key: 11, name: "111111111111", url: assets.icon, scroes: 2000 },
{ key: 12, name: "121212121212", url: assets.icon, scroes: 2000 },
{ key: 13, name: "13131313", url: assets.icon, scroes: 2000 },
{ key: 14, name: "1414141414", url: assets.icon, scroes: 2000 },
{ key: 15, name: "1515151515", url: assets.icon, scroes: 2000 },
{ key: 16, name: "1616161616", url: assets.icon, scroes: 2000 },
];/**
* 创建排行榜
*/
function drawRankPanel() {
//绘制背景
context.drawImage(assets.panel, offsetX_rankToBorder, offsetY_rankToBorder, RankWidth, RankHeight);
//绘制标题
let title = assets.title;
//根据title的宽高计算一下位置;
let titleX = offsetX_rankToBorder + (RankWidth - title.width) / 2;
let titleY = offsetY_rankToBorder + title.height + 50;
context.drawImage(title, titleX, titleY);
//获取当前要渲染的数据组
let start = perPageMaxNum * page;
currentGroup = totalGroup.slice(start, start + perPageMaxNum);
//创建头像Bar
drawRankByGroup(currentGroup);
//创建按钮
drawButton()
}
/**
* 根据屏幕大小初始化所有绘制数据
*/
function init() {
//排行榜绘制数据初始化
RankWidth = stageWidth * 4 / 5;
RankHeight = stageHeight * 4 / 5;
barWidth = RankWidth * 4 / 5;
barHeight = RankWidth / perPageMaxNum;
offsetX_rankToBorder = (stageWidth - RankWidth) / 2;
offsetY_rankToBorder = (stageHeight - RankHeight) / 2;
preOffsetY = (RankHeight - barHeight) / (perPageMaxNum + 1); startX = offsetX_rankToBorder + offsetX_rankToBorder;
startY = offsetY_rankToBorder + preOffsetY;
avatarSize = barHeight - 10;
intervalX = barWidth / 20;
textOffsetY = (barHeight + fontSize) / 2;
textMaxSize = 250;
indexWidth = context.measureText("99").width; //按钮绘制数据初始化
buttonWidth = barWidth / 3;
buttonHeight = barHeight / 2;
buttonOffset = RankWidth / 3;
lastButtonX = offsetX_rankToBorder + buttonOffset - buttonWidth;
nextButtonX = offsetX_rankToBorder + 2 * buttonOffset;
nextButtonY = lastButtonY = offsetY_rankToBorder + RankHeight - 50 - buttonHeight;
let data = wx.getSystemInfoSync();
canvasWidth = data.windowWidth;
canvasHeight = data.windowHeight;
}/**
* 创建两个点击按钮
*/
function drawButton() {
context.drawImage(assets.button, nextButtonX, nextButtonY, buttonWidth, buttonHeight);
context.drawImage(assets.button, lastButtonX, lastButtonY, buttonWidth, buttonHeight);
}/**
* 根据当前绘制组绘制排行榜
*/
function drawRankByGroup(currentGroup) {
for (let i = 0; i < currentGroup.length; i++) {
let data = currentGroup[i];
drawByData(data, i);
}
}/**
* 根据绘制信息以及当前i绘制元素
*/
function drawByData(data, i) {
let x = startX;
//绘制底框
context.drawImage(assets.box, startX, startY + i * preOffsetY, barWidth, barHeight);
x += 10;
//设置字体
context.font = fontSize + "px Arial";
//绘制序号
context.fillText(data.key + "", x, startY + i * preOffsetY + textOffsetY, textMaxSize);
x += indexWidth + intervalX;
//绘制头像
context.drawImage(data.url, x, startY + i * preOffsetY + (barHeight - avatarSize) / 2, avatarSize, avatarSize);
x += avatarSize + intervalX;
//绘制名称
context.fillText(data.name + "", x, startY + i * preOffsetY + textOffsetY, textMaxSize);
x += textMaxSize + intervalX;
//绘制分数
context.fillText(data.scroes + "", x, startY + i * preOffsetY + textOffsetY, textMaxSize);
}/**
* 点击处理
*/
function onTouchEnd(event) {
let x = event.clientX * sharedCanvas.width / canvasWidth;
let y = event.clientY * sharedCanvas.height / canvasHeight;
if (x > lastButtonX && x < lastButtonX + buttonWidth
&& y > lastButtonY && y < lastButtonY + buttonHeight) {
//在last按钮的范围内
if (page > 0) {
buttonClick(0); }
}
if (x > nextButtonX && x < nextButtonX + buttonWidth
&& y > nextButtonY && y < nextButtonY + buttonHeight) {
//在next按钮的范围内
if ((page + 1) * perPageMaxNum < totalGroup.length) {
buttonClick(1);
}
}}
/**
* 根据传入的buttonKey 执行点击处理
* 0 为上一页按钮
* 1 为下一页按钮
*/
function buttonClick(buttonKey) {
let old_buttonY;
if (buttonKey == 0) {
//上一页按钮
old_buttonY = lastButtonY;
lastButtonY += 10;
page--;
renderDirty = true;
console.log('上一页');
setTimeout(() => {
lastButtonY = old_buttonY;
//重新渲染必须标脏
renderDirty = true;
}, 100);
} else if (buttonKey == 1) {
//下一页按钮
old_buttonY = nextButtonY;
nextButtonY += 10;
page++;
renderDirty = true;
console.log('下一页');
setTimeout(() => {
nextButtonY = old_buttonY;
//重新渲染必须标脏
renderDirty = true;
}, 100);
}}/////////////////////////////////////////////////////////////////// 相关缓存数据/**********************数据相关***************************//**
* 渲染标脏量
* 会在被标脏（true）后重新渲染
*/
let renderDirty = true;/**
* 当前绘制组
*/
let currentGroup = [];
/**
* 每页最多显示个数
* 建议大于等于4个
*/
let perPageMaxNum = 5;
/**
* 当前页数,默认0为第一页
*/
let page = 0;
/***********************绘制相关*************************/
/**
* 舞台大小
*/
let stageWidth;
let stageHeight;
/**
* 排行榜大小
*/
let RankWidth;
let RankHeight;/**
* 每个头像条目的大小
*/
let barWidth;
let barHeight;
/**
* 条目与排行榜边界的水平距离
*/
let offsetX_barToRank
/**
* 绘制排行榜起始点X
*/
let startX;
/**
* 绘制排行榜起始点Y
*/
let startY;
/**
* 每行Y轴间隔offsetY
*/
let preOffsetY;
/**
* 按钮大小
*/
let buttonWidth;
let buttonHeight;
/**
* 上一页按钮X坐标
*/
let lastButtonX;
/**
* 下一页按钮x坐标
*/
let nextButtonX;
/**
* 上一页按钮y坐标
*/
let lastButtonY;
/**
* 下一页按钮y坐标
*/
let nextButtonY;
/**
* 两个按钮的间距
*/
let buttonOffset;/**
* 字体大小
*/
let fontSize = 45;
/**
* 文本文字Y轴偏移量
* 可以使文本相对于图片大小居中
*/
let textOffsetY;
/**
* 头像大小
*/
let avatarSize;
/**
* 名字文本最大宽度，名称会根据
*/
let textMaxSize;
/**
* 绘制元素之间的间隔量
*/
let intervalX;
/**
* 排行榜与舞台边界的水平距离
*/
let offsetX_rankToBorder;
/**
* 排行榜与舞台边界的竖直距离
*/
let offsetY_rankToBorder;
/**
* 绘制排名的最大宽度
*/
let indexWidth;//////////////////////////////////////////////////////////
/**
* 监听点击
*/
wx.onTouchEnd((event) => {
var l = event.changedTouches.length;
for (var i = 0; i < l; i++) {
onTouchEnd(event.changedTouches[i]);
}
});/**
* 资源加载
*/
function preloadAssets() {
var preloaded = 0;
var count = 0;
for (var asset in assets) {
count++;
var img = wx.createImage();
img.onload = function () {
preloaded++;
if (preloaded == count) {
setTimeout(function () {
createScene();
}, 500);
}
}
img.src = assets[asset];
assets[asset] = img;
}
}
/**
* 绘制屏幕
* 这个函数会在加载完所有资源之后被调用
*/
function createScene() {
if (sharedCanvas.width && sharedCanvas.height) {
console.log('初始化完成')
stageWidth = sharedCanvas.width;
stageHeight = sharedCanvas.height;
} else {
console.log(`sharedCanvas.width:${sharedCanvas.width} sharedCanvas.height：${sharedCanvas.height}`)
}
init();
requestAnimationFrame(loop);
}
/**
* 循环函数
* 每帧判断一下是否需要渲染
* 如果被标脏，则重新渲染
*/
function loop() {
if (renderDirty) {
console.log(`stageWidth :${stageWidth} stageHeight:${stageHeight}`)
context.setTransform(1, 0, 0, 1, 0, 0);
context.clearRect(0, 0, sharedCanvas.width, sharedCanvas.height);
drawRankPanel();
renderDirty = false;
}
requestAnimationFrame(loop);
}