修改

Scripts/thwj/thwjHelper.js

@@ -224,7 +224,7 @@ function base64encode(str) {
     // let data = CryptoJS.enc.Utf8.parse(hexStr);
     // let base64Data = CryptoJS.enc.Base64.stringify(data);
     let base = new Base64();
-    let base64Data = base.encode("str");
+    let base64Data = base.encode(str);
     return 'data:image/png;base64,' + base64Data;
 }