Question

我有一个简单的客户注册表。我在数据网格视图旁边放置了一些文本框，以便我可以添加和更新用户。这工作正常，但仍然如此。

最近，我添加了一个用于客户端定义的新窗体，因此当双击一行时，会出现一个包含必填字段的表单，显示客户端信息并允许您更改它们。单击“确定”按钮将保存对SQL数据库的更改。

使用网格视图旁边的字段，当我更新用户信息时，网格视图会立即更新并显示数据，但在使用新表单更新数据时，即使我双击，网格视图中也不会显示更新再次排。当我关闭应用程序并再次运行它时，我将看到更新的数据。

我为主窗体添加了一个激活事件，以便从数据库中再次选择数据来更新网格视图，但没有成功。这是我用于侧面板更新的代码：

private void btnUpdate_Click(object sender, EventArgs e)
{
    if (btnUpdate.Text == "Update")
    {
        txtUsername.Text = ClientsGridView.CurrentRow.Cells["Username"].Value.ToString();
        txtPassword.Text = ClientsGridView.CurrentRow.Cells["Password"].Value.ToString();
        txtUID.Text = ClientsGridView.CurrentRow.Cells["UID"].Value.ToString();
        txtName.Text = ClientsGridView.CurrentRow.Cells["Name"].Value.ToString();
        chkIsActive.Checked = (bool)ClientsGridView.CurrentRow.Cells["IsActive"].Value;
        chkItemListAccess.Checked = (bool)ClientsGridView.CurrentRow.Cells["ItemListAccess"].Value;
        chkMaterialSumAccess.Checked = (bool)ClientsGridView.CurrentRow.Cells["MaterialSumAccess"].Value;
        chkPartListAccess.Checked = (bool)ClientsGridView.CurrentRow.Cells["PartListAccess"].Value;
        chkPriceListAccess.Checked = (bool)ClientsGridView.CurrentRow.Cells["PriceListAccess"].Value;

        btnUpdate.Text = "Apply Update";
        btnSubmit.Enabled = false;
        txtUsername.ReadOnly = true;
    }
    else if (btnUpdate.Text == "Apply Update")
    {
        if (ClientFormValidation())
        {
            int id = Convert.ToInt32(ClientsGridView.CurrentRow.Cells["ID"].Value.ToString());
            var SelectedUser = from Client in ClientsContext.Clients
                               where Client.ID == id
                               select Client;
            if (SelectedUser.Count() == 1)
            {
                Client UpdatingClient = SelectedUser.Single();
                UpdatingClient.Password = txtPassword.Text.Trim();
                UpdatingClient.UID = txtUID.Text.Trim();
                UpdatingClient.Name = txtName.Text.Trim();
                UpdatingClient.IsActive = chkIsActive.Checked;
                UpdatingClient.ItemListAccess = chkItemListAccess.Checked;
                UpdatingClient.MaterialSumAccess = chkMaterialSumAccess.Checked;
                UpdatingClient.PartListAccess = chkPartListAccess.Checked;
                UpdatingClient.PriceListAccess = chkPriceListAccess.Checked;

                ClientsContext.SubmitChanges();

            }
            ShowAll();
            ClearClientForm();
            btnUpdate.Text = "Update";
            btnSubmit.Enabled = true;
            txtUsername.ReadOnly = false;
        }


    }
}

这适用于客户定义表单：

private void btnOK_Click(object sender, EventArgs e)
{
    if(ISnewUser)
    {
        InsertNewClient();
    }
    else if(!ISnewUser)
    {
        UpdateClient();
    }
    this.Close();
}

private void UpdateClient()
{
    if (ClientFormValidation())
    {

        var SelectedUser = from Client in ClientsContext.Clients
                           where Client.ID == id
                           select Client;
        if (SelectedUser.Count() == 1)
        {
            Client UpdatingClient = SelectedUser.Single();
            UpdatingClient.Password = txtPassword.Text.Trim();
            UpdatingClient.UID = txtUID.Text.Trim();
            UpdatingClient.Name = txtName.Text.Trim();
            UpdatingClient.IsActive = chkUserActiveSatus.Checked;
            UpdatingClient.ItemListAccess = chkItemListAccess.Checked;
            UpdatingClient.MaterialSumAccess = chkMaterialSummeryAccess.Checked;
            UpdatingClient.PartListAccess = chkPartListAccess.Checked;
            UpdatingClient.PriceListAccess = chkPriceListAcess.Checked;
            ClientsContext.SubmitChanges();


        }

    }
}

有谁能告诉我这段代码有什么问题？

Answer 1

  *var SelectedUser = from Client in ClientsContext.Clients
                                           where Client.ID == id
                                           select Client;

它是Iqueryable，应用.ToList（）来获取内存，然后修补更改。

相反，我建议，使用此，

var SelectedUser = (from Client in ClientsContext.Clients
                                           where Client.ID == id
                                           select Client).FirstOrDefault();
if(SelectedUser!=null){
                    SelectedUser.Password = txtPassword.Text.Trim();
                    SelectedUser.UID = txtUID.Text.Trim();
                    SelectedUser.Name = txtName.Text.Trim();
                    SelectedUser.IsActive = chkUserActiveSatus.Checked;
                    SelectedUser.ItemListAccess = chkItemListAccess.Checked;
                    SelectedUser.MaterialSumAccess = chkMaterialSummeryAccess.Checked;
                    SelectedUser.PartListAccess = chkPartListAccess.Checked;
                    SelectedUser.PriceListAccess = chkPriceListAcess.Checked;
                    ClientsContext.SubmitChanges();
}
else{
//write your logic
}*

我只是将异常处理留给你。

Answer 2

我自己解决了，我在初始化客户端定义表单时传递了一个Client对象。所以为了更新我使用完全相同的对象没有得到它的parapeter并再次从数据库中选择它：

public frmClientDefinition(Client thisClient=null)
        {

            InitializeComponent();
            if (thisClient!=null)
            {
                User = thisClient;
                id = thisClient.ID;
                ISnewUser = false;
                txtName.Text = thisClient.Name;
                txtUsername.Text = thisClient.Username;
                txtPassword.Text = thisClient.Password;
                txtDate.Text = thisClient.Date.ToString();
                txtUID.Text = thisClient.UID;
                chkUserActiveSatus.Checked = thisClient.IsActive;
                chkItemListAccess.Checked = thisClient.ItemListAccess;
                chkPartListAccess.Checked = thisClient.PartListAccess;
                chkMaterialSummeryAccess.Checked = thisClient.MaterialSumAccess;
                chkPriceListAcess.Checked = thisClient.PriceListAccess;
                chkFullPriceListAccess.Checked = false;
                chkOfficialRecieptAccess.Checked = false;
                chkNonOfficialRecieptAccess.Checked = false;
                chkAdvancedPriceControlsAccess.Checked = false;
                chkFullPriceListSaveAccess.Checked = false;
                chkOfficialRecieptSaveAccess.Checked = false;
                chkNonOfficialRecieptSaveAccess.Checked = false;
                txtUsername.ReadOnly = true;
            }
            txtDate.Text = DateTime.Now.ToString();
        }

并更新此代码段：

private void UpdateClient()
        {
            if (ClientFormValidation())
            {
                    User.Password = txtPassword.Text.Trim();
                    User.UID = txtUID.Text.Trim();
                    User.Name = txtName.Text.Trim();
                    User.IsActive = chkUserActiveSatus.Checked;
                    User.ItemListAccess = chkItemListAccess.Checked;
                    User.MaterialSumAccess = chkMaterialSummeryAccess.Checked;
                    User.PartListAccess = chkPartListAccess.Checked;
                    User.PriceListAccess = chkPriceListAcess.Checked;
                    ClientsContext.SubmitChanges();
            }
        }

提交更改后，DataGridView不会更新c＃linq

2 个答案: