前端實現下載pdf文件

async downloadFun() { // 下載使用說明書
                const InstructionManualvv = await InstructionManual();

                let blob = new Blob([InstructionManualvv.data], {type: 'application/pdf;charset=UTF-8'});
                let fileName = '使用說明書.pdf';
                if (window.navigator.msSaveOrOpenBlob) {
                    navigator.msSaveBlob(blob, fileName)
                } else {
                    var link = document.createElement('a');
                    link.href = window.URL.createObjectURL(blob);
                    link.download = fileName;
                    link.click();
                    window.URL.revokeObjectURL(link.href) //釋放內存
                }
            },