如何使用閉包對象作爲參數來創建調用（或與之結合）另一個表達式的表達式？

Question

我首先會顯示一個完全正常的同類不使用表達式樹：

public class ClassUsingFuncs 
{ 
    public SomeClass SomeProperty { get; set; } 

    public void DoSomethingUsingFuncWithoutArgument(Func<bool> funcWithoutArgument) 
    { 
    } 

    public void DoSomethingUsingFuncWithArgument(Func<SomeClass, bool> funcWithArgument) 
    { 
     Func<bool> funcWithoutArgument =() => funcWithArgument(SomeProperty); 
     DoSomethingUsingFuncWithoutArgument(funcWithoutArgument); 
    } 
} 

使用表達式樹時，我該如何實現這個等價？如果我需要LINQKit或其他庫來實現這一點，這沒有任何問題。

public class ClassUsingExpressionTrees 
{ 
    public SomeClass SomeProperty { get; set; } 

    public void DoSomethingUsingExpressionWithoutArgument(Expression<Func<bool>> expressionWithoutArgument) 
    { 
    } 

    public void DoSomethingUsingExpressionWithArgument(Expression<Func<SomeClass, bool>> expressionWithArgument) 
    { 
     Expression<Func<bool>> expressionWithoutArgument = ? 
     DoSomethingUsingExpressionWithoutArgument(expressionWithoutArgument); 
    } 
} 

Answer 1

public void DoSomethingUsingExpressionWithArgument(Expression<Func<SomeClass, bool>> expressionWithArgument) 
{ 
    var thisExpr = Expression.Constant(this); 
    var pExpr = Expression.Property(thisExpr, "SomeProperty"); 
    var invokeExpr = Expression.Invoke(expressionWithArgument, pExpr); 
    Expression<Func<bool>> expressionWithoutArgument = Expression.Lambda<Func<bool>>(invokeExpr); 
    DoSomethingUsingExpressionWithoutArgument(expressionWithoutArgument); 
}