1.首先我们要把想保存的图片绘制在画布上

<view class='container'>
 <canvas style='width:{{canvasWidth}}px; height:{{canvasHeight}}px' class="canvas" id="canvas" canvas-id="canvas" disable-scroll="true">
 </canvas>
 <button bindtap='clickMe'>保存图片</button>
</view>

2.我们在看看看js代码在用wx.canvasToTempFilePath方法会返回一个tempFilePath图片路径

// canvas 全局配置
var context = null;
var rpx
var posterHeight = 0
var posterWidth = 0
var avatarPadding = 0 //距离边界
var avatarRadiu = 0 //头像半径
var textScale = 0 //文字比例

//注册页面
Page({

 data: {
  img: "../../images/img1.jpg",myCanvasWidth: 0,myCanvasHeight: 0,posterHeight: 0,},onLoad: function (options) {
  var that = this
  var myCanvasWidth = that.data.myCanvasWidth  //为了让图片满铺页面
  var myCanvasHeight = that.data.canvasHeight
  context = wx.createCanvasContext('canvas');

  wx.getSystemInfo({
   success: function (res) {
    myCanvasWidth = res.screenWidth
    myCanvasHeight = res.screenHeight
    posterWidth = Math.round(res.screenWidth * 0.68) //计算让画布图片自适应
    posterHeight = Math.round(posterWidth * 1920 / 1080)
    avatarPadding = Math.round(posterWidth * 20 / 375)
    avatarRadiu = Math.round(posterWidth * 25 / 375)
    textScale = Math.round(posterWidth / 375)
    rpx = res.windowWidth / 375;
    that.setData({
     myCanvasWidth: myCanvasWidth,myCanvasHeight: myCanvasHeight,posterHeight: posterHeight
    })
    context.drawImage(that.data.img,that.data.myCanvasWidth,that.data.myCanvasHeight); //画布绘制图片
    context.draw();

   },})
 },clickMe: function () { //保存图片
  wx.canvasToTempFilePath({
   canvasId: 'canvas',fileType: 'jpg',success: function (res) {
    console.log(res)
    wx.saveImageToPhotosAlbum({
     filePath: res.tempFilePath,success(res) {
      console.log(res)
      wx.hideLoading();
      wx.showToast({
       title: '保存成功',});
      // //存入服务器
      // wx.uploadFile({
      //  url: 'a.PHP',//接口地址
      //  filePath: res.tempFilePath,//  name: 'file',//  formData: {                 //HTTP 请求中其他额外的 form data
      //   'user': 'test'
      //  },//  success: function (res) {
      //   console.log(res);

      //  },//  fail: function (res) {
      //   console.log(res);
      //  },//  complete: function (res) {
      //  }
      // });
     },fail() {
      wx.hideLoading()
     }
    })
   }
  })
 },})

3,css样式 直接给画布设置高度宽度就可以 图片会铺满屏幕

总结

以上所述是小编给大家介绍的微信小程序点击保存图片到本机功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！
如果你觉得本文对你有帮助，欢迎转载，烦请注明出处，谢谢！