Canvastotempfilepath of wechat

When canvas After drawing the picture , We want to save it locally , Or upload to the server ,

In two ways , One is to save pictures base64 Image information
The other is Save the binary data of the picture to the local , The default is png Format

The first method , have access to canvas Object's toDataURL(); Get one base64 Encoded picture information

canvas.toDataURL
Here's a reminder it is to be noted that canvas.getContext();
Let's draw a picture , Writing is used convas.getContext() The object of acquisition , and toDataURL It is used. canvas object ,
There are pictures to prove

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The second method , You can upload pictures to the server in wechat programs , We won't upload here , Use wechat ready-made api Save it locally

   wx.canvasToTempFilePath({
    
      canvasId: "canvas",
      canvas:that.data.canvasobj,
      x:0,
      y:0,
      success(res){
    
        console.log(res.tempFilePath);
        wx.saveImageToPhotosAlbum({
    
          filePath:res.tempFilePath,
          success(res1){
    
            wx.showToast({
    
              title: ' Saved successfully ',
              duration: 1000,
            });
          }
        })
      },
      fail(e){
    
        console.log(e);
      }
    },that)

above filepath：res.tempFilePath Value Something like this http://tmp/Q7HOHsK5uM3v9a28c4b4cfd44850fa422994a8ab457f.png
You can open... In wechat developer tool , But it can't be opened in Google
The above code can see , It is saved to the local picture library