商店表達 <Func<T, bool> &gt;作為類的屬性

Question

我有一個擴展System.Web.UI.WebControls.GridView控件的類。 我想擁有一個可以保存我的EF表達式以在整個控件中使用的屬性。

問題是，T沒有定義。

public sealed class NCGridView : GridView
{
    private Expression<Func<T, bool>> _where;

    public void LoadWhere(Expression<Func<T, bool>> where)
    {
        _where = where;
    }
}

RedHat建議嘗試

    private Expression<Func<BaseModel, bool>> _where;

    public void LoadWhere<T>(Expression<Func<T, bool>> where) where T : BaseModel
    {
       // Cannot cast from: Expression<Func<T, bool>> to:  Expression<Func<BaseModel, bool>>
        _where = where;
    }

Answer 1

答案2：更新：

public Expression<Func<BaseModel, bool>> LoadWhere<T>(Expression<Func<T, bool>> where) where T : BaseModel
{
    where = LambdaExpression.Lambda<Func<BaseModel, bool>>(where.Body,where.Parameters);
}

答案1：使用：

Expression<Func<object, bool>>

支持任何類型。

樣品：

Expression<Func<object, bool>> exp = p => ((Table1)p).Code == 1;
var a = new MyContext().Table1.Where(exp).ToList();