我从API中获取数据，并将其放入react中的表中，但当我试图从表中的一行编辑数据时。这给了我一个错误“PUT 400（错误请求）”。如何更改FormData（）以接收来自“”的值，然后再从后端接收它？

---editar2.js---

handlerSubmit = async (event) => {

        event.preventDefault();
        let formData = new FormData();
        formData.set("", event.target.legenda.value);
        
        let resposta = await fetch("api/FotografiasAPI/" + this.props.idLinha, {
            method: "PUT",
            headers:{'Accept':'application/json','Content-Type':'application/json'},
            body: formData
        });
        if (!resposta.ok) {
        console.error("error:" + resposta.status);
        }
        return await resposta.json();
}
    render(){
        return(
        <Modal
        {...this.props}>
                <Form onSubmit={this.handlerSubmit}>
                    <Form.Group controlId="legenda">
                        <Form.Label>legenda</Form.Label>
                        <Form.Control defaultValue = {this.props.legenda} type="text"name="legenda" required  placeholder="legenda"/>
                    </Form.Group>
                    <Form.Group>
                        <Button variant="primary" type="submit">
                            Editar Restaurante
                        </Button>
                    </Form.Group>
                </Form>    
        </Modal>  
    );}}

---后端---

[HttpPut("{id}")]
public async Task<IActionResult> PutFotografias(int id, [FromForm] Fotografias fotografias)
{
    if (id != fotografias.ID)
    {return BadRequest();}

    _context.Entry(fotografias).State = EntityState.Modified;

    try
    {await _context.SaveChangesAsync();}

    catch (DbUpdateConcurrencyException)
    {
        if (!FotografiasExists(id))
        {return NotFound();}

        else
        {throw;}}

    return NoContent();
}

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