dillonlfy/weapp-qrcode

把二维码封装成组件的时候无法导出图片，而且导出图片的时候进入的是初始化方法的callback

Opened this issue · 1 comments

gooczy commented

1、exportImage的方法我改成了这个，这样保存图片的时候才能够保存成功，如果canvas封装成组件的话，canvasToTempFilePath要传入当前canvas的实例

QRCode.prototype.exportImage = function (callback) {
if (callback && typeof callback === 'function') {

    wx.canvasToTempFilePath({
        x: 0,
        y: 0,
        width: this._htOption.width,
        height: this._htOption.height,
        destWidth: this._htOption.width,
        destHeight: this._htOption.height,
        canvasId: this.canvasId,
        success: (res) => {
          callback({path: res.tempFilePath})
        }
    }, this._htOption.usingIn)
  } 
}

2、另外，在初始化的方法内，生成图片本地链接的方法改成了这个，增加了this._htOption.callback的回调
_oContext.draw(false, () => {
setTimeout(() => {
this.exportImage(this._htOption.callback)
}, 800)
})

zeratel commented

if (this._htOption.usingIn) {
wx.canvasToTempFilePath({
x: 0,
y: 0,
width: this._htOption.width,
height: this._htOption.height,
destWidth: this._htOption.width,
destHeight: this._htOption.height,
canvasId: this.canvasId,
success: (res) => {
// console.log('exportImage2');
this._htOption.callback({path: res.tempFilePath})
},
fail: (res) => {
// console.log('exportImage3',res);
},
},this._htOption.usingIn)
报错是
canvasToTempFilePath: fail canvas is empty , 报这个错是因为调取 wx.canvasToTempFilePath 接口获取不到canvas，

所以原因是上下文的this，各位自行解决吧

  • 👍1