（1）链接的 onclick 事件被先执行，其次是 href 属性下的动作（页面跳转，或 javascript 伪链接）
（2）假设链接中同时存在 href 与 onclick，如果想让 href 属性下的动作不执行，onclick 必须得到一个 false 的返回值。
（3）如果页面过长有滚动条，且希望通过链接的 onclick 事件执行操作。应将它的 href 属性设为 javascript:void (0);，而不要是 #，这可以防止不必要的页面跳动；
（4）如果在链接的 href 属性中调用一个有返回值的函数，当前页面的内容将被此函数的返回值代替；
<a href="javascript:void(0);" onclick="download()" style="color: blue" download>Download</a> |
function download() { | |
let url = window.location.protocol + '//' + window.location.host + '/download'; | |
url = url + '?userAge=' + $("#userAge").val(); | |
url = url + '&userId='+$("#userId").val(); | |
url = url + '&userName='+encodeURIComponent(encodeURIComponent($("#userName").val())); | |
window.location.href = url; | |
return false; | |
} |
@xxx.route('/download', methods=['GET']) | |
@login_required | |
def download(): | |
user_id = request.args.get('userId') | |
user_age = request.args.get('userAge') | |
user_name = urlparse.unquote(request.args.get('userName')) | |
logger.info('userId: {0}, userAge: {1}, userName: {2}'.format(str(user_id), str(user_age), str(user_name))) | |
connection = engine.raw_connection() | |
df = pd.DataFrame() | |
try: | |
cursor = connection.cursor() | |
cursor.callproc("xxx_xxxx", [user_name, user_age]) | |
sql = "select * from xxx_xxx where userid=:user_id " | |
df = pd.read_sql_query(sql, engine, params=[user_id]) | |
cursor.close() | |
connection.commit() | |
except Exception as e: | |
logger.error('Get data error:' + str(e.message)) | |
logger.error(traceback.format_exc()) | |
finally: | |
connection.close() | |
output = BytesIO() | |
writer = pd.ExcelWriter(output) | |
df.to_excel(writer, index=False, sheet_name='Sheet') | |
workbook = writer.book | |
header_fmt = workbook.add_format({ | |
'font_size': 14, | |
'bold': True, | |
'fg_color': '#D7E4BC', | |
'border': 1}) | |
sheet_table = writer.sheets['Sheet'] | |
for col_num, value in enumerate(df.columns.values): | |
sheet_table.write(0, col_num, value, header_fmt) | |
sheet_table.set_column('A:A', 30) | |
sheet_table.set_column('B:B', 10) | |
sheet_table.set_column('C:C', 30) | |
sheet_table.set_column('D:I', 15) | |
sheet_table.set_column('J:K', 20) | |
workbook.close() | |
writer.close() | |
output.seek(0) | |
return send_file(output, attachment_filename="Excel_Name.xlsx", as_attachment=True) |
