问题说明

这是因为MenuItem是Select组件的直接子组件。其作用方式与“选定”菜单文档中所述相同。您可以看到，当打开Menu（或者在我们的示例中是Select）时，焦点会自动放在选定的MenuItem上。这就是为什么TextField首先会失去焦点（即使我们给它附加了一个autoFocus属性）。
好的，我们可以简单地在TextField上使用useRef钩子，然后在Select打开时调用focus()方法。就像这样：

var inputRef = useRef(undefined);
...
<Select onAnimationEnd={() -> inputRef.current.focus()} ... >
    ...
    <TextField ref={inputRef} ... />
    ...
</Select>

”””没有那么快，有一个陷阱！**
这里的东西打破：您打开了选择窗口，焦点如预期的那样转移到输入字段。然后插入将过滤掉当前选定值的搜索文本。现在，如果你用退格键删除文本，直到当前选中的项目再次出现，你会看到焦点将自动从输入字段放置到当前选中的选项。这可能看起来像是一个可行的解决方案，但你可以看到用户体验受到的影响，我们没有得到我们想要的预期稳定的行为。

解决方案

我发现你的问题有点模糊，没有任何代码和适当的解释，但我仍然觉得它很有用，因为我正在寻找与你完全相同的解决方案：可搜索的选择MUI组件，具有良好的用户体验。所以请注意，这是我对你想要的工作解决方案的假设。
这里有一个CodeSandbox和我的工作解决方案。所有重要的部分都在代码注解和这里解释：

• 最重要的更改是将MenuProps={{ autoFocus: false }}属性添加到Select组件，并将autoFocus属性添加到TextField组件。
• 我将搜索TextField放入ListSubheader中，这样它就不会作为菜单中的可选项。即，我们可以点击搜索输入而不触发任何选择。
• 我添加了一个自定义的renderValue函数。如果搜索文本将排除当前选定的选项，这将防止在Select的值字段中呈现空字符串。
• 我已经使用onKeyDown函数禁用了TextField上的事件传播。这将防止在键入时自动选择项目（这是默认的Select行为）
• [奖金]你可以很容易地扩展这个组件与多选择支持，这是我最终为我的项目，但我不会包括这里的细节，因为它的范围内你的问题。

MUI自动完成组件可能正是您所需要的[https：//mui.com/components/autocomplete/]（MUI自动完成）
自动完成是MUI库提供的组件。它具有与选择选项相同的功能，此外还提供了搜索选项沿着其他改善开发人员体验的选项。下面是自动完成组件的一个小片段：

import * as React from 'react';
import TextField from '@mui/material/TextField';
import Autocomplete from '@mui/material/Autocomplete';

export default function ComboBox() {
  return (
    <Autocomplete
      disablePortal
      id="combo-box-demo"
      options={top100Films}
      sx={{ width: 300 }}
      renderInput={(params) => <TextField {...params} label="Movie" />}
    />
  );
}

// Top 100 films as rated by IMDb users. http://www.imdb.com/chart/top
const top100Films = [
  { label: 'The Shawshank Redemption', year: 1994 },
  { label: 'The Godfather', year: 1972 },
  { label: 'The Godfather: Part II', year: 1974 },
  { label: 'The Dark Knight', year: 2008 },
  { label: '12 Angry Men', year: 1957 },
  { label: "Schindler's List", year: 1993 },
  { label: 'Pulp Fiction', year: 1994 },
  {
    label: 'The Lord of the Rings: The Return of the King',
    year: 2003,
  },
  { label: 'The Good, the Bad and the Ugly', year: 1966 },
  { label: 'Fight Club', year: 1999 },
  {
    label: 'The Lord of the Rings: The Fellowship of the Ring',
    year: 2001,
  },
  {
    label: 'Star Wars: Episode V - The Empire Strikes Back',
    year: 1980,
  },
  { label: 'Forrest Gump', year: 1994 },
  { label: 'Inception', year: 2010 },
  {
    label: 'The Lord of the Rings: The Two Towers',
    year: 2002,
  },
  { label: "One Flew Over the Cuckoo's Nest", year: 1975 },
  { label: 'Goodfellas', year: 1990 },
  { label: 'The Matrix', year: 1999 },
  { label: 'Seven Samurai', year: 1954 },
  {
    label: 'Star Wars: Episode IV - A New Hope',
    year: 1977,
  },
  { label: 'City of God', year: 2002 },
  { label: 'Se7en', year: 1995 },
  { label: 'The Silence of the Lambs', year: 1991 },
  { label: "It's a Wonderful Life", year: 1946 },
  { label: 'Life Is Beautiful', year: 1997 },
  { label: 'The Usual Suspects', year: 1995 },
  { label: 'Léon: The Professional', year: 1994 },
  { label: 'Spirited Away', year: 2001 },
  { label: 'Saving Private Ryan', year: 1998 },
  { label: 'Once Upon a Time in the West', year: 1968 },
  { label: 'American History X', year: 1998 },
  { label: 'Interstellar', year: 2014 },
  { label: 'Casablanca', year: 1942 },
  { label: 'City Lights', year: 1931 },
  { label: 'Psycho', year: 1960 },
  { label: 'The Green Mile', year: 1999 },
  { label: 'The Intouchables', year: 2011 },
  { label: 'Modern Times', year: 1936 },
  { label: 'Raiders of the Lost Ark', year: 1981 },
  { label: 'Rear Window', year: 1954 },
  { label: 'The Pianist', year: 2002 },
  { label: 'The Departed', year: 2006 },
  { label: 'Terminator 2: Judgment Day', year: 1991 },
  { label: 'Back to the Future', year: 1985 },
  { label: 'Whiplash', year: 2014 },
  { label: 'Gladiator', year: 2000 },
  { label: 'Memento', year: 2000 },
  { label: 'The Prestige', year: 2006 },
  { label: 'The Lion King', year: 1994 },
  { label: 'Apocalypse Now', year: 1979 },
  { label: 'Alien', year: 1979 },
  { label: 'Sunset Boulevard', year: 1950 },
  {
    label: 'Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb',
    year: 1964,
  },
  { label: 'The Great Dictator', year: 1940 },
  { label: 'Cinema Paradiso', year: 1988 },
  { label: 'The Lives of Others', year: 2006 },
  { label: 'Grave of the Fireflies', year: 1988 },
  { label: 'Paths of Glory', year: 1957 },
  { label: 'Django Unchained', year: 2012 },
  { label: 'The Shining', year: 1980 },
  { label: 'WALL·E', year: 2008 },
  { label: 'American Beauty', year: 1999 },
  { label: 'The Dark Knight Rises', year: 2012 },
  { label: 'Princess Mononoke', year: 1997 },
  { label: 'Aliens', year: 1986 },
  { label: 'Oldboy', year: 2003 },
  { label: 'Once Upon a Time in America', year: 1984 },
  { label: 'Witness for the Prosecution', year: 1957 },
  { label: 'Das Boot', year: 1981 },
  { label: 'Citizen Kane', year: 1941 },
  { label: 'North by Northwest', year: 1959 },
  { label: 'Vertigo', year: 1958 },
  {
    label: 'Star Wars: Episode VI - Return of the Jedi',
    year: 1983,
  },
  { label: 'Reservoir Dogs', year: 1992 },
  { label: 'Braveheart', year: 1995 },
  { label: 'M', year: 1931 },
  { label: 'Requiem for a Dream', year: 2000 },
  { label: 'Amélie', year: 2001 },
  { label: 'A Clockwork Orange', year: 1971 },
  { label: 'Like Stars on Earth', year: 2007 },
  { label: 'Taxi Driver', year: 1976 },
  { label: 'Lawrence of Arabia', year: 1962 },
  { label: 'Double Indemnity', year: 1944 },
  {
    label: 'Eternal Sunshine of the Spotless Mind',
    year: 2004,
  },
  { label: 'Amadeus', year: 1984 },
  { label: 'To Kill a Mockingbird', year: 1962 },
  { label: 'Toy Story 3', year: 2010 },
  { label: 'Logan', year: 2017 },
  { label: 'Full Metal Jacket', year: 1987 },
  { label: 'Dangal', year: 2016 },
  { label: 'The Sting', year: 1973 },
  { label: '2001: A Space Odyssey', year: 1968 },
  { label: "Singin' in the Rain", year: 1952 },
  { label: 'Toy Story', year: 1995 },
  { label: 'Bicycle Thieves', year: 1948 },
  { label: 'The Kid', year: 1921 },
  { label: 'Inglourious Basterds', year: 2009 },
  { label: 'Snatch', year: 2000 },
  { label: '3 Idiots', year: 2009 },
  { label: 'Monty Python and the Holy Grail', year: 1975 },
];