Python点划线侧边栏和导航栏相互重叠

Question

我是新来的Ploly Dash，并试图开发一个多页应用程序。如何同时使用Sidebar和Navbar？

下面是一个示例代码，其中侧栏位于导航栏上方。我试过搜索类似的例子，但没有找到。

任何帮助都会很棒。谢谢

导入破折号导入dash_bootstrap_componentsdbc导入dash_core_componentsdcc导入dash_html_componentshtml从dash.dependencies导入输入，输出，状态

# link fontawesome to get the chevron icons
FA = "https://use.fontawesome.com/releases/v5.8.1/css/all.css"


app = dash.Dash(external_stylesheets=[dbc.themes.BOOTSTRAP, FA])

# the style arguments for the sidebar. We use position:fixed and a fixed width
SIDEBAR_STYLE = {
    "position": "fixed",
    "top": 0,
    "left": 0,
    "bottom": 0,
    "width": "16rem",
    "padding": "2rem 1rem",
    "background-color": "#f8f9fa",
}

# the styles for the main content position it to the right of the sidebar and
# add some padding.
CONTENT_STYLE = {
    "margin-left": "18rem",
    "margin-right": "2rem",
    "padding": "2rem 1rem",
}

submenu_1 = [
    html.Li(
        # use Row and Col components to position the chevrons
        dbc.Row(
            [
                dbc.Col("Menu 1"),
                dbc.Col(
                    html.I(className="fas fa-chevron-right mr-3"), width="auto"
                ),
            ],
            className="my-1",
        ),
        id="submenu-1",
    ),
    # we use the Collapse component to hide and reveal the navigation links
    dbc.Collapse(
        [
            dbc.NavLink("Page 1.1", href="/page-1/1"),
            dbc.NavLink("Page 1.2", href="/page-1/2"),
        ],
        id="submenu-1-collapse",
    ),
]

submenu_2 = [
    html.Li(
        dbc.Row(
            [
                dbc.Col("Menu 2"),
                dbc.Col(
                    html.I(className="fas fa-chevron-right mr-3"), width="auto"
                ),
            ],
            className="my-1",
        ),
        id="submenu-2",
    ),
    dbc.Collapse(
        [
            dbc.NavLink("Page 2.1", href="/page-2/1"),
            dbc.NavLink("Page 2.2", href="/page-2/2"),
        ],
        id="submenu-2-collapse",
    ),
]


sidebar = html.Div(
    [
        html.H2("Sidebar", className="display-5"),
        html.Hr(),
        html.P(
            "A sidebar with collapsible navigation links", className="lead"
        ),
        dbc.Nav(submenu_1 + submenu_2, vertical=True),
    ],
    style=SIDEBAR_STYLE,
    id="sidebar",
)

PLOTLY_LOGO = "https://images.plot.ly/logo/new-branding/plotly-logomark.png"

search_bar = dbc.Row(
    [
        dbc.Col(dbc.Input(type="search", placeholder="Search")),
        dbc.Col(
            dbc.Button("Search", color="primary", className="ml-2"),
            width="auto",
        ),
    ],
    no_gutters=True,
    className="ml-auto flex-nowrap mt-3 mt-md-0",
    align="center",
)

navbar = dbc.Navbar(
    [
        html.A(
            # Use row and col to control vertical alignment of logo / brand
            dbc.Row(
                [
                    dbc.Col(html.Img(src=PLOTLY_LOGO, height="30px")),
                    dbc.Col(dbc.NavbarBrand("Navbar", className="ml-2")),
                ],
                align="center",
                no_gutters=True,
            ),
            href="https://plot.ly",
        ),
        dbc.NavbarToggler(id="navbar-toggler"),
        dbc.Collapse(search_bar, id="navbar-collapse", navbar=True),
    ],
    color="dark",
    dark=True,
)

content = html.Div(id="page-content", style=CONTENT_STYLE)

app.layout = html.Div([dcc.Location(id="url"), navbar,sidebar, content])


# this function is used to toggle the is_open property of each Collapse
def toggle_collapse(n, is_open):
    if n:
        return not is_open
    return is_open


# this function applies the "open" class to rotate the chevron
def set_navitem_class(is_open):
    if is_open:
        return "open"
    return ""


for i in [1, 2]:
    app.callback(
        Output(f"submenu-{i}-collapse", "is_open"),
        [Input(f"submenu-{i}", "n_clicks")],
        [State(f"submenu-{i}-collapse", "is_open")],
    )(toggle_collapse)

    app.callback(
        Output(f"submenu-{i}", "className"),
        [Input(f"submenu-{i}-collapse", "is_open")],
    )(set_navitem_class)


@app.callback(Output("page-content", "children"), [Input("url", "pathname")])
def render_page_content(pathname):
    if pathname in ["/", "/page-1/1"]:
        return html.P("This is the content of page 1.1!")
    elif pathname == "/page-1/2":
        return html.P("This is the content of page 1.2. Yay!")
    elif pathname == "/page-2/1":
        return html.P("Oh cool, this is page 2.1!")
    elif pathname == "/page-2/2":
        return html.P("No way! This is page 2.2!")
    # If the user tries to reach a different page, return a 404 message
    return dbc.Jumbotron(
        [
            html.H1("404: Not found", className="text-danger"),
            html.Hr(),
            html.P(f"The pathname {pathname} was not recognised..."),
        ]
    )
# add callback for toggling the collapse on small screens
@app.callback(
    Output("navbar-collapse", "is_open"),
    [Input("navbar-toggler", "n_clicks")],
    [State("navbar-collapse", "is_open")],
)
def toggle_navbar_collapse(n, is_open):
    if n:
        return not is_open
    return is_open

if __name__ == "__main__":
    app.run_server(port=8888, debug=True)

Answer 1

GitHub回购中报告了同样的问题：https://github.com/facultyai/dash-bootstrap-components/issues/321.建议调整侧边栏填充：

SIDEBAR_STYLE = {
    ...,
    "padding": "4rem 1rem 2rem",
    ...,
}