微信小程序海报分享方案

previewImage预览能加载临时路径的图片吗

//适配不一样屏幕大小的canvas

setCanvasSize: function () {

var size = {};

try {

var res = wx.getSystemInfoSync();

var scale = 750 / 686;//不一样屏幕下canvas的适配比例；设计稿是750宽

var width = res.windowWidth / scale;

var height = width;//canvas画布为正方形

size.w = width;

size.h = height;

} catch (e) {

// Do something when catch error

}

return size;

},

createQrCode: function (url, canvasId, cavW, cavH) {

//调用插件中的draw方法，绘制二维码图片

QR.qrApi.draw(url, canvasId, cavW, cavH);

var that = this;

//二维码生成以后调用canvasToTempImage();延迟1s，不然获取图片路径为空

var st = setTimeout(function () {

that.canvasToTempImage();

clearTimeout(st);

}, 1000);



},

//获取临时缓存照片路径，存入data中

canvasToTempImage: function () {

var that = this;

wx.canvasToTempFilePath({

canvasId: 'mycanvas',

success: function (res) {

var tempFilePath = res.tempFilePath;

that.setData({

imagePath: tempFilePath,

});

},

fail: function (res) {

}

});

}, index: function () {

wx.reLaunch({

url: '../../pages/index/index'

})

}

,

//点击图片进行预览，长按保存分享图片

previewImg: function (e) {

var img = this.data.imagePath

console.log(this.data.imagePath)

wx.previewImage({

current: img, // 当前显示图片的http连接

urls: [img] // 须要预览的图片http连接列表

})

// console.log(img)



}