Question

所以我有一个“程序”列表，我想这样做，当我按下一个按钮时，我的DataGrid中添加了一行新的“程序”，但我有一些问题，当我添加一个新行程序的数量从零开始我希望它从最后一个数字继续。

以下是添加行的方式：

private void Add_download_Click(object sender, RoutedEventArgs e)
{
    for (int a = 0; a < 1; a++)
    {
        PL.List_Programs.Add(UpdateList(a));
    }
}

private Programs UpdateList(int a)
{
    Programs P = new Programs();

    //Add a way to get the number of currently downloading programs (e.g.: ProgramID + a)
    int aAsIDNum = PL.ProgramList().IndexOf();

    //Both of these are used to toghter because I cant make a decimal random generator
    double RndSizeGen = new Random().Next(10, 50);
    int RndSizeGen1 = new Random().Next(1, 9);

    //Generates a random number to be used as the progress precent
    int RndProgressGen = new Random().Next(10, 80);

    Programs _programs = new Programs
    {
        ProgramID = a,
        Name = $"Program{a}",
        Size = Convert.ToDouble($"{RndSizeGen}.{RndSizeGen1}"),
        Progress = RndProgressGen
    };

    //Returns the updated list of programs 
    return _programs;
}

以下是“计划：

的列表

public ObservableCollection<Programs> List_Programs {get; set;}

public ObservableCollection<Programs> ProgramList()
{

    List_Programs = new ObservableCollection<Programs>
    {
        new Programs { _programid = 1, _name = "Program0", _size = 5.8, _progress = 100 },
        new Programs { _programid = 2, _name = "Program1", _size = 7.1, _progress = 36 },
        new Programs { _programid = 3, _name = "Program2", _size = 1.4, _progress = 44 },
        new Programs { _programid = 4, _name = "Program3", _size = 6.5, _progress = 100 },
        new Programs { _programid = 5, _name = "Program4", _size = 2.5, _progress = 89 },
        new Programs { _programid = 6, _name = "Program5", _size = 9.6, _progress = 68 },
        new Programs { _programid = 7, _name = "Program6", _size = 5.3, _progress = 90 },
        new Programs { _programid = 8, _name = "Program7", _size = 2.2, _progress = 100 },
        new Programs { _programid = 9, _name = "Program8", _size = 83.7, _progress = 18 }
    };

    return List_Programs;
}

以下是我使用的变量：

public class Programs : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void OnProperyChanged(string PropertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(PropertyName));
    }

    public int _programid;
    public int ProgramID
    {
        get { return _programid; }
        set
        {
            _programid = value;
            OnProperyChanged(nameof(ProgramID));
        }
    }

    public string _name;
    public string Name
    {
        get { return _name; }
        set
        {
            _name = value;
            OnProperyChanged(nameof(Name));
        }
    }

    public double _size;
    public double Size
    {
        get { return _size; }
        set
        {
            _size = value;
            OnProperyChanged(nameof(Size));
        }
    }

    public  double _progress;
    public double Progress
    {
        get { return _progress; }
        set
        {
            _progress = value;
            OnProperyChanged(nameof(Progress));
        }
    }

    public ICollectionView ProgramsView { get; set; }
}

数据网格/ XAML中

<DataGrid x:Name="DG_List" AutoGenerateColumns="False" IsReadOnly="true"
          ColumnWidth="*" Grid.Column="3" Grid.RowSpan="3">
</DataGrid >

图片供参考：

告诉我是否遗漏了什么

Answer 1

for (int a = 0; a < 1; a++)
{
    PL.List_Programs.Add(UpdateList(a));
}

这一行表示您始终使用0 ID创建新项目。（for循环从0开始并执行1次迭代）

如果未从列表中删除项目，则可以将List.Count值作为新id传递：

PL.List_Programs.Add(UpdateList(PL.List_Programs.Count))

如果可以更改，请找到max id并使用下一个数字：

PL.List_Programs.Add(UpdateList(PL.List_Programs.Max(p=>p.ProgramID)+1))

Answer 2

每次调用Add_download_Click事件处理程序时增加a的值：

private void Add_download_Click(object sender, RoutedEventArgs e)
{
    int a = 10;
    if (PL.List_Programs.Count > 0)
    {
        a = PL.List_Programs[PL.List_Programs.Count - 1].ProgramID + 1;
    }
    PL.List_Programs.Add(UpdateList(a));
}

按照以前的值

2 个答案: