修改 sop预览功能

src/views/modules/qc/PQCResultEntry.vue

@@ -422,7 +422,6 @@
     <el-dialog title="SOP预览" :visible.sync="pdfDialogVisible" width="80%">
 <!--      <pdf v-if="pdfUrl" :src="pdfUrl" style="width:100%;height:600px"/>-->
       <iframe
-        v-if="pdfUrl"
         :src="pdfUrl"
         width="100%"
         height="600px"