C# 在c中完成组合框数据加载后加载Windows窗体#

我有一个名为frmememployees的员工的

表单

，我需要在其中加载几个

组合框

，其中包含国家、类别、国籍等数据

现在，当用户点击打开frmEmployees时，窗口被卡住一位，然后打开。我假设这是由于数据加载和初始化组合框。 现在！我想要的是，在点击按钮打开frmEmployees之后，运行一个进度条，直到数据加载完成，然后打开表单

public frmEmployee()
    {
        InitializeComponent();
        con = new Connection();

        LoadComboboxDS();
    }

我也试过了

private void FrmEmployee_Load(object sender, EventArgs e)
    {
        LoadComboboxDS();
    }



private void LoadComboboxDS()
    {
        //company
        var _companies = con.Companies.Where(x => x.IsDeleted == false).ToList();
        _companies.Insert(0,new data.Models.CompanyModels.Company { Address = new data.Models.Address(), Code = null, Name = "--Select--", BaseCurrency = new data.Models.Currency() });
        cbCompany.DataSource = _companies;
        cbCompany.DisplayMember = "Name";
        cbCompany.ValueMember = "ID";

        //gender
        cbGender.DataSource = Enum.GetValues(typeof(Gender));

        //merital status
        cbMeritalStatus.DataSource = Enum.GetValues(typeof(MaritalStatus));

        //citizenship
        var _citizenships = con.Countries.Select(x => x.Citizenship).Distinct().ToList();
        _citizenships.Insert(0, "--Select--");
        cbCitizenship.DataSource = _citizenships;
        cbCitizenship.DisplayMember = "Citizenship";

        //nationality
        var _nations = con.Countries.Select(x => x.Name).Distinct().ToList();
        _nations.Insert(0, "--Select--");
        cbNationality.DataSource = _nations;
        cbNationality.DisplayMember = "Name";

        //domicile
        var _domiciles = con.Countries.Select(x => x.Name).Distinct().ToList();
        _domiciles.Insert(0, "--Select--");
        cbDomicile.DataSource = _domiciles;
        cbDomicile.DisplayMember = "Name";

        //cast category
        var _casts = con.CastCategories.Select(x => new {x.ShortText, x.Description}).Distinct().ToList();
        _casts.Insert(0, new { ShortText = "", Description = "--Select--" });
        cbCategory.DataSource = _casts;
        cbCategory.DisplayMember = "Description";
        cbCategory.ValueMember = "ShortText";

        //religion 
        cbReligion.DataSource = Enum.GetValues(typeof(Religion));

    }

---

您可以使用EntityFramework6的异步扩展方法使代码异步

首先，分离数据访问层和表示层：

public static class MyRepository // consider not static, just an example
{
    public static async Task<List<Company>> GetCompanies()
    {
        using (var connection = new Connection()) // consider factory
        {
            return await con.Companies.Where(x => x.IsDeleted == false).ToListAsync();
        }
    }

    public async Task<List<Citizenship>> GetCitizenships()
    {
        using (var connection = new Connection()) // factory?
        {
            return await con.Countries.Select(x => x.Citizenship).Distinct().ToList();
        }
    }
}

现在，您只需要让窗体在构造函数中接受完整的数据，而不是让窗体加载打破抽象的数据：

public class FrmEmployees
{
    public FrmEmployees(List<Company> companies, List<Citizenship> citizenships)
    {
        companies.Insert(0,new data.Models.CompanyModels.Company { Address = new data.Models.Address(), Code = null, Name = "--Select--", BaseCurrency = new data.Models.Currency() });
        cbCompany.DataSource = companies;
        cbCompany.DisplayMember = "Name";
        cbCompany.ValueMember = "ID";

        citizenships.Insert(0, "--Select--");
        cbCitizenship.DataSource = _citizenships;
        cbCitizenship.DisplayMember = "Citizenship";

        // etc.
    }
}

公共类员工
{
公众雇员（上市公司、上市公民）
{
插入（0，new data.Models.CompanyModels.CompanyModels.Company{Address=new data.Models.Address（），Code=null，Name=“--Select--”，BaseCurrency=new data.Models.Currency（））；
cbCompany.DataSource=公司；
cbCompany.DisplayMember=“Name”；
cbCompany.ValueMember=“ID”；
公民身份。插入（0，“--Select--”；
cbcitizensity.DataSource=\u公民身份；
cbcidential.DisplayMember=“公民身份”；
//等等。
}
}

---

有一点很重要：可以将许多任务和数据传递给表单构造函数。如果所有这些数据将经常用于设置，那么您可能希望将“获取所有这些内容”逻辑封装到一个地方，以消除可能的代码重复。

查看我所做的。。。如果有人可以查看我的代码，这将是可观的

public class EmployeeFormDataRepesenter
{
    public List<Company> Companies { get; set; }
    public List<Country> Countries { get; set; }
    public List<CastCategory> CastCategories { get; set; }
}

public void LoadData(EmployeeFormDataRepesenter representer)
    {

        //gender
        cbGender.DataSource = Enum.GetValues(typeof(Gender));
        //merital status
        cbMeritalStatus.DataSource = Enum.GetValues(typeof(MaritalStatus));
        //religion 
        cbReligion.DataSource = Enum.GetValues(typeof(Religion));

        //company
        var _companies = representer.Companies;
        _companies.Insert(0, new data.Models.CompanyModels.Company { Address = new data.Models.Address(), Code = null, Name = "--Select--", BaseCurrency = new data.Models.Currency() });
        cbCompany.DataSource = _companies;
        cbCompany.DisplayMember = "Name";
        cbCompany.ValueMember = "ID";

        //citizenship
        var _citizenships = representer.Countries.Select(x => x.Citizenship).ToList();
        _citizenships.Insert(0, "--Select--");
        cbCitizenship.DataSource = _citizenships;
        cbCitizenship.DisplayMember = "Citizenship";

        //nationality
        var _nations = representer.Countries.Select(x => x.Name).ToList();
        _nations.Insert(0, "--Select--");
        cbNationality.DataSource = _nations;
        cbNationality.DisplayMember = "Name";

        //domicile
        var _domiciles = representer.Countries.Select(x => x.Name).ToList();
        _domiciles.Insert(0, "--Select--");
        cbDomicile.DataSource = _domiciles;
        cbDomicile.DisplayMember = "Name";

        //cast category
        var _casts = representer.CastCategories.Select(x => new { x.ShortText, x.Description }).Distinct().ToList();
        _casts.Insert(0, new { ShortText = "", Description = "--Select--" });
        cbCategory.DataSource = _casts;
        cbCategory.DisplayMember = "Description";
        cbCategory.ValueMember = "ShortText";
    }




private async void btnEmplyee_Click(object sender, EventArgs e)
    {
        con = new Connection();
        Action showProgress = () => frmStatrup._progressBar.Visible = true;
        Action hideProgress = () => frmStatrup._progressBar.Visible = false;

        EmployeeFormDataRepesenter representer;

        Task<List<Company>> _taskCompany = new Task<List<Company>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.Companies.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });

        Task<List<Country>> _taskCountry = new Task<List<Country>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.Countries.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });

        Task<List<CastCategory>> _taskCasts = new Task<List<CastCategory>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.CastCategories.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });


        _taskCompany.Start();
        var _companies = await _taskCompany;

        _taskCountry.Start();
        var _countries = await _taskCountry;

        _taskCasts.Start();
        var _casts = await _taskCasts;


        if (_companies.Count != 0)
        {
            representer = new EmployeeFormDataRepesenter();
            representer.Companies = _companies;
            representer.Countries = _countries;
            representer.CastCategories = _casts;
        }
        else
        {
            representer = null;
        }

        if (representer != null)
        {
            frmEmployee _emp = new frmEmployee();
            _emp.LoadData(representer);
            Functions.OpenForm(_emp, this.ParentForm);
        }
    }

公共类EmployeeFormDataRepenter
{
上市公司{get；set；}
公共列表国家{get；set；}
公共列表类别{get；set；}
}
公共无效加载数据（EmployeeFormDataRepenster重新输入）
{
//性别
cbGender.DataSource=Enum.GetValues（typeof（Gender））；
//经位
cbMeritalStatus.DataSource=Enum.GetValues（typeof（MaritalStatus））；
//宗教信仰
cbReligion.DataSource=Enum.GetValues（typeof（宗教））；
//公司
var_companies=代表公司；
_插入（0，new data.Models.CompanyModels.CompanyModels.Company{Address=new data.Models.Address（），Code=null，Name=“--Select--”，BaseCurrency=new data.Models.Currency（））；
cbCompany.DataSource=\u公司；
cbCompany.DisplayMember=“Name”；
cbCompany.ValueMember=“ID”；
//公民身份
var_citizenships=representer.Countries.Select（x=>x.Citizenship.ToList（）；
_公民身份。插入（0，“--Select--”；
cbcitizensity.DataSource=\u公民身份；
cbcidential.DisplayMember=“公民身份”；
//国籍
var_nations=representer.Countries.Select（x=>x.Name.ToList（）；
_国家。插入（0，“--”选择“-”；
cbnationary.DataSource=\u国家；
cbnational.DisplayMember=“Name”；
//住所
var_domiciles=representer.Countries.Select（x=>x.Name.ToList（）；
_住所。插入（0，“--选择--”；
cbDomicile.DataSource=_住所；
cbDomicile.DisplayMember=“Name”；
//演员类别
var\u casts=representer.CastCategories.Select（x=>new{x.ShortText，x.Description}）.Distinct（）.ToList（）；
_Insert（0，new{ShortText=”“，Description=“--Select--”}）；
cbCategory.DataSource=\u强制转换；
cbCategory.DisplayMember=“说明”；
cbCategory.ValueMember=“ShortText”；
}
私有异步无效btnEmplyee\u单击（对象发送方，事件参数）
{
con=新连接（）；
动作showProgress=（）=>frmStatrup.\u progressBar.Visible=true；
动作hideProgress=（）=>frmStatrup.\u progressBar.Visible=false；
EmployeeFormDataRepenter代表输入；
任务公司=新任务（（）=>
{
BeginInvoke（显示进度）；
var list=con.companys.toListSync（）；
开始发汗；
如果（列表！=null）
返回列表。结果；
返回null；
});
任务_taskCountry=新任务（（）=>
{
BeginInvoke（显示进度）；
var list=con.Countries.ToListAsync（）；
开始发汗；
如果（列表！=null）
返回列表。结果；
返回null；
});
任务_taskCasts=新任务（（）=>
{
BeginInvoke（显示进度）；
var list=con.CastCategories.toListSync（）；
开始发汗；
如果（列表！=null）
返回列表。结果；
返回null；
});
_taskCompany.Start（）；
var_companys=等待公司；
_taskCountry.Start（）；
var_countries=等待任务国；
_taskCasts.Start（）；
var _casts=wait _taskCasts；
如果（_companys.Count！=0）
{
representer=new employeeFormDataRepenter（）；
代表公司=_家公司；
representer.Countries=\u国家；
representer.CastCategories=\u强制转换；
}
其他的
{
representer=null；
}
如果（重新输入！=null）
{
frmEmployee_emp=新frmEmployee（）；
_emp.LoadData（重新输入）；
Functions.OpenForm（_emp，this.ParentForm）；
}
}

您应该为进度条使用backgroundworker。更简单的方法是将光标图标更改为加载符号。您可以推荐任何示例代码吗。因为我试过一些，但没有luck@kurdyBackgroundworker将不适用于UI元素。用户界面控件需要

public class EmployeeFormDataRepesenter
{
    public List<Company> Companies { get; set; }
    public List<Country> Countries { get; set; }
    public List<CastCategory> CastCategories { get; set; }
}

public void LoadData(EmployeeFormDataRepesenter representer)
    {

        //gender
        cbGender.DataSource = Enum.GetValues(typeof(Gender));
        //merital status
        cbMeritalStatus.DataSource = Enum.GetValues(typeof(MaritalStatus));
        //religion 
        cbReligion.DataSource = Enum.GetValues(typeof(Religion));

        //company
        var _companies = representer.Companies;
        _companies.Insert(0, new data.Models.CompanyModels.Company { Address = new data.Models.Address(), Code = null, Name = "--Select--", BaseCurrency = new data.Models.Currency() });
        cbCompany.DataSource = _companies;
        cbCompany.DisplayMember = "Name";
        cbCompany.ValueMember = "ID";

        //citizenship
        var _citizenships = representer.Countries.Select(x => x.Citizenship).ToList();
        _citizenships.Insert(0, "--Select--");
        cbCitizenship.DataSource = _citizenships;
        cbCitizenship.DisplayMember = "Citizenship";

        //nationality
        var _nations = representer.Countries.Select(x => x.Name).ToList();
        _nations.Insert(0, "--Select--");
        cbNationality.DataSource = _nations;
        cbNationality.DisplayMember = "Name";

        //domicile
        var _domiciles = representer.Countries.Select(x => x.Name).ToList();
        _domiciles.Insert(0, "--Select--");
        cbDomicile.DataSource = _domiciles;
        cbDomicile.DisplayMember = "Name";

        //cast category
        var _casts = representer.CastCategories.Select(x => new { x.ShortText, x.Description }).Distinct().ToList();
        _casts.Insert(0, new { ShortText = "", Description = "--Select--" });
        cbCategory.DataSource = _casts;
        cbCategory.DisplayMember = "Description";
        cbCategory.ValueMember = "ShortText";
    }




private async void btnEmplyee_Click(object sender, EventArgs e)
    {
        con = new Connection();
        Action showProgress = () => frmStatrup._progressBar.Visible = true;
        Action hideProgress = () => frmStatrup._progressBar.Visible = false;

        EmployeeFormDataRepesenter representer;

        Task<List<Company>> _taskCompany = new Task<List<Company>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.Companies.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });

        Task<List<Country>> _taskCountry = new Task<List<Country>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.Countries.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });

        Task<List<CastCategory>> _taskCasts = new Task<List<CastCategory>>(() =>
        {
            BeginInvoke(showProgress);
            var list = con.CastCategories.ToListAsync();
            BeginInvoke(hideProgress);
            if (list != null)
                return list.Result;
            return null;
        });


        _taskCompany.Start();
        var _companies = await _taskCompany;

        _taskCountry.Start();
        var _countries = await _taskCountry;

        _taskCasts.Start();
        var _casts = await _taskCasts;


        if (_companies.Count != 0)
        {
            representer = new EmployeeFormDataRepesenter();
            representer.Companies = _companies;
            representer.Countries = _countries;
            representer.CastCategories = _casts;
        }
        else
        {
            representer = null;
        }

        if (representer != null)
        {
            frmEmployee _emp = new frmEmployee();
            _emp.LoadData(representer);
            Functions.OpenForm(_emp, this.ParentForm);
        }
    }