在网上经常看到很多微信小程序换头像的，比如国庆节，圣诞节等节日头像框，一键换头像，其实原理很简单，就是微信小程序授权登陆后，获取你原始头像，在你选择国旗等头像后和你授权获取头像合并生成一张新头像，另存下载。
国庆新年圣诞节日头像框小程序源码带流量主广告，加了很多素材，不喜欢素材可以自己换，采用ColorUI小程序框架，无后台。
此源码本是uniapp破解很多代码被打包过乱码的，经过站长原创改写，采用源码生JS复写。
其主要功能和逻辑：
授权获取微信头像
头像边框分类及边框图，所有边框图必须放在远程服务器，图片太大小程序不允许
选择切换头像功能，
小程序canvas生成图片
XML源码：
<view class="wrapper">
<view class="container">
<image class="page-bg _img" mode="widthFix" src="{{bgImage}}"></image>
<view class="avatar-container" style="{{'margin-top:'+(showHeight+'px')+';'}}" id="avatar-container">
<!-- 屏蔽上传iocn -->
<!-- <block wx:if="{{avatarImage}}">
<view class="xiangji-icon"><label data-event-opts="{{[['tap',[['chooseImage',['$event']]]]]}}" class="iconfont iconxiangji2 _span" bindtap="__e"></label></view>
</block> -->
<image class="avatar-img _img" id="avatar-img" src="{{avatarImage}}"></image>
<block wx:if="{{currentFrame}}">
<image class="avatar-frame _img" src="{{frameImage}}"></image>
</block>
<block wx:if="{{!avatarImage}}">
<view class="empty-avatar-view">
<image class="empty-avatar _img" src="/static/image/avatar_empty.svg"></image>
<button class="cu-btn round action-btn btn-primary" id="btn-choose-img" bindtap="getUserProfile">获取头像</button>
</view>
</block>
<view class="prev _p" wx:if="{{!avatarImage}}" bindtap="getUserProfile"><label class="iconfont iconqianfanicon _span"></label></view>
<view class="next _p" wx:if="{{!avatarImage}}" bindtap="getUserProfile"><label class="iconfont iconhoufanicon _span"></label></view>
<view class="prev _p" wx:if="{{avatarImage}}" data-type="pre" bindtap="cutover"><label class="iconfont iconqianfanicon _span"></label></view>
<view class="next _p" wx:if="{{avatarImage}}" data-type="next" bindtap="cutover"><label class="iconfont iconhoufanicon _span"></label></view>
</view>
<view class="_div"><canvas class="canvas" canvasId="canvas"></canvas></view>
<view class="panel assets-container">
<view style="display:flex;" clss="category-list" class="_div">
<block wx:for="{{categoryList}}" wx:for-item="item" wx:for-index="index" wx:key="index">
<view class="_div"><text class="{{['category ',item.id===currentCategory?'active':'']}}" data-categroy-id="{{item.id}}" bindtap="imageListTab">{{item.name}}</text></view>
</block>
</view>
<scroll-view class="assets-scroll-view" scroll-into-view="{{bottomId}}" scrollX="true">
<block wx:for="{{imageList}}" wx:for-item="item" wx:for-index="index" wx:key="index">
<view class="{{['assets','_div',index===savedNum&&avatarImage?'active-border':'']}}" id="{{'img'+index}}">
<image src="{{item.src}}" data-index="{{index}}" data-src="{{item.src}}" bindtap="selectAvatarImage" class="_img"></image>
</view>
</block>
</scroll-view>
</view>
<view class="flex justify-around">
<button class="cu-btn round action-btn" openType="share" id="btn-choose-img" bindtap="share">分享给朋友</button>
<button class="cu-btn round action-btn btn-primary" id="btn-save" bindtap="saveCans">保存到相册</button></view>
<view class="ad-container">
<view binderror="__e" bindload="__e" unitId="adunit-43f7c4189a8e7c35" class="_div"></view>
</view>
</view>
</view>
JS代码：
// pages/main/index.js
Page({
/**
* 页面的初始数据
*/
data: {
bgImage: "/static/image/bg_image.jpg",
title: ["快来制作2022新年头像框", "您收到一个好看的头像请注意查收", "您有个新年头像待查收", "2022专属王者头像框"],
showHeight: 220,
avatarUrl: "",
subscribe: true,
savedNum: 0,
cansWidth: 280,
cansHeight: 280,
avatarImage: "",
userInfo: '',
currentFrame: {}, //目前选取的头像框
frameImage: '', //选中的头像框
bottomId: null,
currentCategory: "guoqing",
categoryList: [{
id: "guoqing",
name: "国庆"
}, {
id: "years",
name: "新年"
}, {
id: "hot",
name: "热门",
}, {
id: "wangzhe",
name: "王者",
}, {
id: "shengdan",
name: "圣诞",
}, {
id: "wansheng",
name: "万圣",
}], //头像分类
imageList: [],
assetsList: {
//头像背景框需要放在远程服务器
guoqing: [{
src: "/static/touxiangkuang/guoqing/1.png"
}, {
src: "/static/touxiangkuang/guoqing/2.png"
{
src: "/static/touxiangkuang/xinnian/93.png"
}],
}
},
/**
* 生命周期函数--监听页面加载
*/
onLoad(options) {
this.initScreen()
},
/**
* 生命周期函数--监听页面初次渲染完成
*/
onReady() {
},
/**
* 生命周期函数--监听页面显示
*/
onShow() {
},
/**
* 生命周期函数--监听页面隐藏
*/
onHide() {
},
/**
* 生命周期函数--监听页面卸载
*/
onUnload() {
},
/**
* 页面相关事件处理函数--监听用户下拉动作
*/
onPullDownRefresh() {
},
/**
* 页面上拉触底事件的处理函数
*/
onReachBottom() {
},
/**
* 用户点击右上角分享
*/
onShareAppMessage() {
},
//初始化屏幕
initScreen() {
var that = this;
wx.getSystemInfo({
success(res) {
var height = res.windowHeight;
var showHeight = 220;
if (height > 900) {
showHeight = 340;
} else if (height > 850) {
showHeight = 330;
} else if (height > 700) {
showHeight = 300;
} else if (height > 600) {
showHeight = 240;
} else {
showHeight = 140;
}
that.setData({
showHeight: showHeight
})
}
});
this.setData({
imageList: this.data.assetsList[this.data.currentCategory],
frameImage: this.data.assetsList[this.data.currentCategory][0].src
})
},
getUserProfile(e) {
// 推荐使用 wx.getUserProfile 获取用户信息，开发者每次通过该接口获取用户个人信息均需用户确认
// 开发者妥善保管用户快速填写的头像昵称，避免重复弹窗
wx.getUserProfile({
desc: '用于完善会员资料', // 声明获取用户个人信息后的用途，后续会展示在弹窗中，请谨慎填写
success: (res) => {
//console.log('res:',res);
this.setData({
userInfo: res.userInfo,
avatarImage: res.userInfo.avatarUrl
})
}
})
},
//切换类型
imageListTab(e) {
var categroyId = e.currentTarget.dataset.categroyId
this.setData({
currentCategory: categroyId,
imageList: this.data.assetsList[categroyId],
savedNum: 0
})
this.changeAsset(this.data.assetsList[categroyId], 0);
},
//选取头像挂件
selectAvatarImage(e) {
var index = e.currentTarget.dataset.index;
var src = e.currentTarget.dataset.src;
// console.log('src:',src);
// console.log('index:',index);
if (this.data.avatarImage) {
this.setData({
savedNum: index,
currentFrame: src,
frameImage: src
})
} else {
wx.showToast({
title: "请先上传图片",
icon: "none",
duration: 2000
});
}
},
// 左右切换
cutover(e) {
var type = e.currentTarget.dataset.type
if (!this.data.avatarImage) {
wx.showToast({
title: "请先上传图片",
icon: "none",
duration: 2000
});
return;
}
if (type == 'next') {
if (this.data.savedNum < this.data.imageList.length - 1) {
this.setData({
savedNum: this.data.savedNum + 1,
frameImage: this.data.imageList[this.data.savedNum].src,
bottomId: "img" + this.data.savedNum
})
} else {
wx.showToast({
title: "已经是最后一张",
icon: "none",
duration: 2000
});
}
} else {
if (this.data.savedNum) {
this.data.savedNum -= 1;
this.data.currentFrame = this.data.imageList[this.data.savedNum];
this.data.bottomId = "img" + this.data.savedNum;
} else {
wx.showToast({
title: "已经是第一张",
icon: "none",
duration: 2000
});
}
}
},
// 选择挂件
changeAsset(data, index) {
if (this.data.avatarImage) {
this.data.savedNum = index;
this.data.currentFrame = data[index];
} else {
wx.showToast({
title: "请先上传图片",
icon: "none",
duration: 2000
});
}
},
draw() {
console.log("绘制头像");
var a = this;
if (a.avatarImage) {
var t = wx.createSelectorQuery();
t.select("#avatar-img").boundingClientRect();
t.exec(function (t) {
var r = wx.createCanvasContext("canvas");
r.clearRect(0, 0, a.cansWidth, a.cansHeight);
wx.getImageInfo({
src: a.avatarImage,
success: function success(res) {
r.drawImage(res.path, 0, 0, a.cansWidth, a.cansHeight);
wx.getImageInfo({
src: a.frameImage,
success: function success(res) {
r.drawImage(res.path, 0, 0, a.cansWidth, a.cansHeight);
r.draw();
setTimeout(function () {
a.saveCans();
}, 100);
}
});
}
});
});
} else {
wx.showToast({
title: "请先上传图片",
icon: "none",
duration: 2000
});
}
},
share() {
wx.showShareMenu({
withShareTicket: true,
menus: ["shareAppMessage", "shareTimeline"]
});
},
// 保存到相册
saveCans() {
// 获取结束
},
// 分享到朋友圈
onShareTimeline() {
return {
title: this.title[(0, _random.random)(0, 4)],
imageUrl: "api/toux/2.jpg",
path: "/pages/main/index"
};
},
// 页面分享
onShareAppMessage() {
return {
title: this.title[(0, _random.random)(0, 4)],
imageUrl: "/api/toux/1.jpg",
path: "/pages/flag/guoqing/main"
};
},
/**
* 获取相册权限
*/
wxSaveAuth() {
return new Promise(function (resolve, reject) {
wx.getSetting({
success: function success(res) {
if (!res.authSetting['scope.writePhotosAlbum']) {
// 如果没有写入权限，则获取写入相册权限
wx.authorize({
scope: 'scope.writePhotosAlbum',
success: function success() {
resolve();
},
fail: function fail(err) {
reject(err); // 用户拒绝授权
wx.showModal({
content: '检测到您没打开相册权限，是否去设置打开？',
confirmText: '确认',
cancelText: '取消',
success: function success(res) {
if (res.confirm) {
wx.openSetting({
success: function success(res) {}
});
}
}
});
}
});
} else {
resolve();
}
},
fail: function fail(e) {
reject(e);
}
});
});
}
})
