ReferenceError：在Dymo框架中未定義標簽

Question

我正在使用Dymo的JS框架。 原始示例可以正常工作，但是即使我不想單擊也可以加載XML。 我只在調用它時才重寫以執行Dymo代碼：

<script type="text/javascript">
       function printnow() {              
               $.get("./cont.label", function(labelXml) {
               label = dymo.label.framework.openLabelXml(labelXml);
               }, "text");
               // open label
               // set label text
               label.setObjectText("MENO", "test");
               label.setObjectText("MUNKA", "test");
               label.setObjectText("DESCRIPTION", test);
               // select printer to print on
               // for simplicity sake just use the first LabelWriter printer
               var printers = dymo.label.framework.getPrinters();
               if (printers.length == 0) throw "No DYMO printers are installed. Install DYMO printers.";
               var printerName = "";
               for (var i = 0; i < printers.length; ++i) {
                   var printer = printers[i];
                   if (printer.printerType == "LabelWriterPrinter") {
                       printerName = printer.name;
                       break;
                   }
               }
               if (printerName == "") throw "No LabelWriter printers found. Install LabelWriter printer";
               // finally print the label
               label.print(printerName);

       };
</script> 

不幸的是，在我調用printnow（）之后； 我收到ReferenceError: label is not defined問題出在哪里？

Answer 1

首先，你必須讀這一個 。

簡而言之，您正在處理異步代碼。 因此，此label.setObjectText("MENO", "test"); 在此label = dymo.label.framework.openLabelXml(labelXml);之前，其余代碼將被執行label = dymo.label.framework.openLabelXml(labelXml); 線。

最后，您必須執行以下操作：

<script type="text/javascript">
       function printnow() {              
               $.get("./cont.label", function(labelXml) {
               var label = dymo.label.framework.openLabelXml(labelXml);
               // open label
               // set label text
               label.setObjectText("MENO", "test");
               label.setObjectText("MUNKA", "test");
               label.setObjectText("DESCRIPTION", test);
               // select printer to print on
               // for simplicity sake just use the first LabelWriter printer
               var printers = dymo.label.framework.getPrinters();
               if (printers.length == 0) throw "No DYMO printers are installed. Install DYMO printers.";
               var printerName = "";
               for (var i = 0; i < printers.length; ++i) {
                   var printer = printers[i];
                   if (printer.printerType == "LabelWriterPrinter") {
                       printerName = printer.name;
                       break;
                   }
               }
               if (printerName == "") throw "No LabelWriter printers found. Install LabelWriter printer";
               // finally print the label
               label.print(printerName);

               }, "text");

       };
</script>