asp core web api http post is null - asp.net

Question

I created a webapi by looking at the ms basic documentation.
ms Doc
it was work
todoitems
Besides todoitems I
Because I wanted to use it in the form of Avatar Chart
Insert the model Avatarchart, create Avatarchartcontext, and make the controller as a scaffold.
solution view
However, when I tried to receive data as a post, the data always came in null.
error
null
this is code
[Route("api/AvatarCharts")]
[ApiController]
public class AvatarChartsController : ControllerBase
{
private readonly AvatarChartContext _context;
public AvatarChartsController(AvatarChartContext context)
{
_context = context;
}
// GET: api/AvatarCharts
[HttpGet]
public async Task<ActionResult<IEnumerable<AvatarChart>>> GetAvatarCharts()
{
return await _context.AvatarCharts.ToListAsync();
}
// GET: api/AvatarCharts/5
[HttpGet("{modelId}")]
public async Task<ActionResult<AvatarChart>> GetAvatarChart(long modelId)
{
var avatarChart = await _context.AvatarCharts.FindAsync(modelId);
if (avatarChart == null)
{
return NotFound();
}
return avatarChart;
}
// PUT: api/AvatarCharts/5
// To protect from overposting attacks, see https://go.microsoft.com/fwlink/?linkid=2123754
[HttpPut("{modelId}")]
public async Task<IActionResult> PutAvatarChart(long modelId, AvatarChart avatarChart)
{
if (modelId != avatarChart.modelId)
{
return BadRequest();
}
_context.Entry(avatarChart).State = EntityState.Modified;
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!AvatarChartExists(modelId))
{
return NotFound();
}
else
{
throw;
}
}
return NoContent();
}
// POST: api/AvatarCharts
// To protect from overposting attacks, see https://go.microsoft.com/fwlink/?linkid=2123754
[HttpPost]
public async Task<ActionResult<AvatarChart>> PostAvatarChart( AvatarChart avatarChart)
{
_context.AvatarCharts.Add(avatarChart);
await _context.SaveChangesAsync();
return CreatedAtAction("GetAvatarChart", new { modelId = avatarChart.modelId }, avatarChart);
}
// DELETE: api/AvatarCharts/5
[HttpDelete("{modelId}")]
public async Task<IActionResult> DeleteAvatarChart(long modelId)
{
var avatarChart = await _context.AvatarCharts.FindAsync(modelId);
if (avatarChart == null)
{
return NotFound();
}
_context.AvatarCharts.Remove(avatarChart);
await _context.SaveChangesAsync();
return NoContent();
}
private bool AvatarChartExists(long modelId)
{
return _context.AvatarCharts.Any(e => e.modelId == modelId);
}
}
public class AvatarChartContext :DbContext
{
public AvatarChartContext(DbContextOptions<AvatarChartContext> options) : base(options)
{
}
public DbSet<AvatarChart> AvatarCharts { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<AvatarChart>().HasKey(c => c.modelId);
}
}
public class AvatarChart
{
[Key]
public long modelId;
public string colorCode;
public long dateTime; //ex 20210101130000
public string name;
public string diagnose;
}
swagger
add postgressql dbenter image description here

Answer 1

Update:
You missed the {get; set;}.
public class AvatarChart
{
[Key]
public long modelId {get; set;}
public string colorCode {get; set;}
public long dateTime {get; set;} //ex 20210101130000
public string name {get; set;}
public string diagnose {get; set;}
}

Answer 2

Can you make these changes and tell me what value is being returned on the variable result. Also, can you validate your ModelState first?
[HttpPost]
public async Task<ActionResult> PostAvatarChart( AvatarChart avatarChart)
{
await _context.AvatarCharts.AddAsync(avatarChart);
var result = await _context.SaveChangesAsync() > 0;
return CreatedAtAction("GetAvatarChart", new { modelId = avatarChart.modelId }, avatarChart);
}