Answers for "map specfict property from list to Datatable"

map specfict property from list to Datatable

public static DataTable ToDataTable<T>(this IList<T> lst, bool includeAll = true)
{
    DataTable dt = new DataTable();
    DataColumn dc;
    PropertyDescriptor pd;
    bool Browsable;

    PropertyDescriptorCollection propCol = TypeDescriptor.GetProperties(typeof(T));

    for (int n = 0; n < propCol.Count; n++)
    {
        pd = propCol[n];
        Type propT = pd.PropertyType;

        dc = new DataColumn(pd.Name);

        // if Nullable, get underlying type
        // the first test may not be needed
        if (propT.IsGenericType && Nullable.GetUnderlyingType(propT) != null )
        {
            propT = Nullable.GetUnderlyingType(propT);
            dc.DataType = propT;
            dc.AllowDBNull = true;
        }
        else
        {
            dc.DataType = propT;
            dc.AllowDBNull = false;
        }

        // is it readonly?
        if (pd.Attributes[typeof(ReadOnlyAttribute)] != null)
        {
            dc.ReadOnly = ((ReadOnlyAttribute)pd.
                     Attributes[typeof(ReadOnlyAttribute)]).IsReadOnly;
        }         

        // DefaultValue ...
        if (pd.Attributes[typeof(DefaultValueAttribute)] != null)
        {
            dc.DefaultValue = ((DefaultValueAttribute)pd.
                   Attributes[typeof(DefaultValueAttribute)]).Value;
        }

        // caption / display name
        dc.ExtendedProperties.Add("DisplayName", dc.Caption);
        if (pd.Attributes[typeof(DisplayNameAttribute)] != null)
        {
            // these are usually present but blank
            string theName = ((DisplayNameAttribute)pd.
                   Attributes[typeof(DisplayNameAttribute)]).DisplayName;
            dc.Caption = string.IsNullOrEmpty(theName) ? dc.Caption : theName;
            // DGV doesnt use Caption...save for later
            dc.ExtendedProperties["DisplayName"] = dc.Caption;
        }

        Browsable = true;
        dc.ExtendedProperties.Add("Browsable", Browsable);
        var foo = pd.Attributes[typeof(BrowsableAttribute)];
        if (pd.Attributes[typeof(BrowsableAttribute)] != null) 
        {
            Browsable = ((BrowsableAttribute)pd.Attributes[typeof(BrowsableAttribute)]).Browsable;
            // no such thing as a NonBrowsable DataColumn
            dc.ExtendedProperties["Browsable"] = Browsable;
        }

        // ToDo: add support for custom attributes

        if (includeAll || Browsable)
        {
            dt.Columns.Add(dc);
        }
    }

    // the lst could be empty such as creating a typed table
    if (lst.Count == 0) return dt;

    if (lst[0] is IDataValuesProvider)
    {
        IDataValuesProvider dvp;
        // copy the data - let the class do the work
        foreach (T item in lst)
        {
            dvp = (IDataValuesProvider)item;
            dt.Rows.Add(dvp.GetDataValues(includeAll).ToArray());
        }
    }
    else
    {
        List<object> values;
        foreach (T item in lst)
        {
            values =  new List<object>();
            // only Browsable columns added
            for (int n = 0; n < dt.Columns.Count; n++)
            {
                 values.Add(propCol[dt.Columns[n].ColumnName].GetValue(item));
            }
            dt.Rows.Add(values.ToArray());
        }
    }   

    return dt;
}