在C＃中單擊按鈕時顯示包含SQL數據的MessageBox

Question

我正在制作一個程序，將我的數據顯示為圖像和標簽。 這是未單擊時我的程序的示例：

未點擊時：

單擊時

問題是，當我單擊其中一張圖像時。 如何將該圖像的ID（在我的SQL中為“ id_movie”）顯示到MessageBox ViewModel類中。

public class VModel
{
    public VModel()
    {
        Clicked = new ClickedCommand(this);
        DataTable dt = new DataTable();

        using (MySqlConnection connection = new MySqlConnection("SERVER=localhost;" + "DATABASE=library;" + "UID=root;" + "PASSWORD=;"))
        {
           MySqlDataAdapter adapter = new MySqlDataAdapter();
           adapter.SelectCommand = new MySqlCommand("Select * from movie_list", connection);
           adapter.Fill(dt);
        }
        Library = dt.DefaultView;
    }
    public ICommand Clicked { get; set; }
    public DataView Library { get; private set; }
}

點擊類

internal class ClickedCommand : ICommand
{
    private VModel vModel;

    public ClickedCommand(VModel vModel)
    {
        this.vModel = vModel;
    }

    public event EventHandler CanExecuteChanged { add { } remove { } }

    public bool CanExecute(object parameter)
    {
        return true;
    }

    public void Execute(object parameter)
    {
        MessageBox.Show("the id that got clicked");
    }
}

Answer 1

如果只需要數據庫的數據，則可以在初始化ClickedCommand時將dt作為參數。

public class VModel
{
    public ICommand Clicked { get; set; }
    public DataView Library { get; private set; }

    public VModel()
    {
        DataTable dt = new DataTable();

        using (MySqlConnection connection = new MySqlConnection("SERVER=localhost;" + "DATABASE=library;" + "UID=root;" + "PASSWORD=;"))
        {
            MySqlDataAdapter adapter = new MySqlDataAdapter();
            adapter.SelectCommand = new MySqlCommand("Select * from movie_list", connection);
            adapter.Fill(dt);
        }

        var Library = dt.DefaultView;
        // this = viewModel or Library as parameter
        var Clicked = new ClickedCommand(this);
    }
}

然后在Execute方法中，訪問vModel或Library字段，具體取決於您作為參數給出的內容並顯示數據。

internal class ClickedCommand : ICommand
{
    private VModel _vModel;
    // private DataView _library;

    public ClickedCommand(VModel vModel)
    {
        _vModel = vModel;
        // _library = library;
    }

    public void Execute(object parameter)
    {
        int rowIndex;
        int.TryParse(((string[])parameter)[0], out rowIndex);
        var stringToSearch = ((string[]) parameter)[1];
        // however you access it here.
        MessageBox.Show(_vModel.Library[rowIndex][stringToSearch]);
        // MessageBox.Show(_library[rowIndex][stringToSearch]);
    }
}