public async Task <IActionResult> Create([Bind("Name,Description,ImagePath")] PirateGroup pirateGroup, string[] selectedPersons)
{
if (_context.PirateGroups.Any(group => group.Name == pirateGroup.Name))
{
ViewBag.NameExists = _localizer["Name '{0}' already exists.", pirateGroup.Name];
PopulateAssignedPerson(selectedPersons);
return(View(pirateGroup));
}
if (ModelState.IsValid)
{
// Try to upload file
if (!(await TryUploadFile(pirateGroup)))
{
PopulateAssignedPerson(selectedPersons);
return(View(pirateGroup));
}
// Update persons
pirateGroup.Persons = new List <Person>();
foreach (var personIdStr in selectedPersons)
{
int personId = int.Parse(personIdStr);
var person = _context.Persons.SingleOrDefault(p => p.Id == personId);
pirateGroup.Persons.Add(person);
person.PirateGroup = pirateGroup;
}
// Save DB
_context.Add(pirateGroup);
await _context.SaveChangesAsync();
return(RedirectToAction(nameof(Index)));
}
PopulateAssignedPerson(selectedPersons);
return(View(pirateGroup));
}
private void UpdatePirateGourpPersons(PirateGroup pirateGroupToUpdate, string[] selectedPersons)
{
var selectedPersonsHS = new HashSet <string>(selectedPersons);
var groupPersons = new HashSet <int>(pirateGroupToUpdate.Persons.Select(p => p.Id));
foreach (var person in _context.Persons)
{
if (selectedPersonsHS.Contains(person.Id.ToString())) // 本次选中这个Person
{
if (!groupPersons.Contains(person.Id)) // 并且这个Person之前不在Group中
{
pirateGroupToUpdate.Persons.Add(person); // 则添加Person到Group
person.PirateGroup = pirateGroupToUpdate;
}
}
else // 本次没有选中这个Person
{
if (groupPersons.Contains(person.Id)) // 并且这个Person之前属于Group
{
pirateGroupToUpdate.Persons.Remove(person); // 则从Group中删除Person
person.PirateGroup = null;
}
}
}
}
/// <summary>
/// Try to upload file and update entity object
/// </summary>
/// <param name="group"></param>
/// <returns>true=No error; false=Has error</returns>
private async Task <bool> TryUploadFile(PirateGroup group)
{
// If no file to upload, return true
if (HttpContext.Request.Form.Files == null)
{
return(true);
}
var file = HttpContext.Request.Form.Files.FirstOrDefault();
if (file == null || file.Length == 0)
{
return(true);
}
// Check extension
string extensionMsg = CheckExtension(file);
if (!string.IsNullOrEmpty(extensionMsg))
{
ViewBag.WrongExtension = extensionMsg;
return(false);
}
// Remove old image
if (group.ImagePath != null)
{
string filePath = Path.Combine(_environment.WebRootPath, group.ImagePath);
if (System.IO.File.Exists(filePath))
{
System.IO.File.Delete(filePath);
}
}
// Upload new image
group.ImagePath = await UploadFile(file);
return(true);
}
// GET: PirateGroups/Create
public IActionResult Create()
{
// 初始化一个空的group，且group中的list也要new。只是为了满足PopulateAssignedPerson函数的要求。
PirateGroup group = new PirateGroup();
group.Persons = new List <Person>();
PopulateAssignedPerson(group);
return(View());
}
public async Task <IActionResult> Edit(int id, [Bind("Id,Name,Description,ImagePath")] PirateGroup pirateGroup, string[] selectedPersons)
{
if (id != pirateGroup.Id)
{
return(NotFound());
}
var pirateGroupToUpdate = await _context.PirateGroups.Include(g => g.Persons).SingleOrDefaultAsync(g => g.Id == id);
// Check if the name exists already
if (_context.PirateGroups.Any(group => group.Name == pirateGroup.Name && group.Id != pirateGroup.Id))
{
ViewBag.NameExists = _localizer["Name '{0}' already exists.", pirateGroup.Name];
PopulateAssignedPerson(selectedPersons);
return(View(pirateGroup));
}
if (ModelState.IsValid)
{
// Update persons
// 把当前的object，用controller创建来的object更新
await TryUpdateModelAsync <PirateGroup>(pirateGroupToUpdate, "", i => i.Name, i => i.Description, i => i.ImagePath);
UpdatePirateGourpPersons(pirateGroupToUpdate, selectedPersons);
// Try to upload file
if (!(await TryUploadFile(pirateGroupToUpdate)))
{
PopulateAssignedPerson(pirateGroupToUpdate);
return(View(pirateGroupToUpdate));
}
// Update DB
try
{
_context.Update(pirateGroupToUpdate);
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!PirateGroupExists(pirateGroup.Id))
{
return(NotFound());
}
else
{
throw;
}
}
return(RedirectToAction(nameof(Index)));
}
return(View(pirateGroup));
}
private void PopulateAssignedPerson(PirateGroup group)
{
var allPersons = _context.Persons;
var groupPersons = new HashSet <int>(group.Persons.Select(p => p.Id));
var viewModel = new List <AssignedPerson>();
foreach (var person in allPersons)
{
viewModel.Add(new AssignedPerson
{
PersonID = person.Id,
Name = person.Name,
Assigned = groupPersons.Contains(person.Id)
});
}
ViewData["Persons"] = viewModel;
}
