我遇到了一个问题：按理说下面的代码在鼠标悬停接近某个点时，应该在工具提示中显示图片，但在VSCode笔记本和浏览器（更新后的Chrome）中都看不到它们。我查过，常见的问题通常与base64编码所给出的图片格式有关，但我已经单独测试过这部分，效果完全正常。

需要澄清的是，我看到的是点的名称“Point X”，在其上方还会出现一个指向图片的损坏链接图标，就像这个。

from dash import Dash, dcc, html, Input, Output
import plotly.graph_objects as go

app = Dash(__name__)

img1 = "<img src='data:image/jpg;base64,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'>"

img2 = "<img src='data:image/jpg;base64,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'>"

df = {'x': [1, 2], 'y': [2, 4], 'images': [img1, img2]}
fig = go.Figure(data=go.Scatter(x=df['x'], y=df['y'], mode='markers', hoverinfo='none'))

app.layout = html.Div([
    dcc.Graph(id='graph-basic-2', figure=fig),
    dcc.Tooltip(id="graph-tooltip")
])

@app.callback(
    Output("graph-tooltip", "show"),
    Output("graph-tooltip", "bbox"),
    Output("graph-tooltip", "children"),
    Input("graph-basic-2", "hoverData"),
)
def display_hover(hoverData):
    if hoverData is None:
        return False, None, None

    pt = hoverData["points"][0]
    bbox = pt["bbox"]
    img_src = df['images'][pt['pointNumber']]

    children = [
        html.Img(src=img_src, style={"width": "100px"}),
        html.P(f"Point {pt['pointNumber']}")
    ]
    return True, bbox, children


app.run(debug=True, port=8050)

解决方案

问题在于你把整个 HTML标签作为src属性传递了。
你试过像这样- img1 = "data:image/...", 不是 img1 = "">。我想是这样的。