public void TestOrExpression () {
Expression<Func<User, bool>> exp1 = u => u.FullName.Contains ("1");
Expression<Func<User, bool>> exp2 = u => u.FullName.Contains ("2");
Expression<Func<User, bool>> exp3 = u => u.FullName.Contains ("3");
var result = exp1.Or (exp2, exp3);
output.WriteLine (result.ToString ());
var parameter = Expression.Parameter (typeof (User), "u");
result = new ParameterReplacer (parameter).Visit (result);
var exp = Expression.Lambda<Func<User, bool>> (result, false, parameter);
Assert.NotEmpty (UserQuery.Where (exp));
Assert.Equal (30, UserQuery.Where (exp).Count ());
}
public static MethodCallExpression GetWhereExpression<TSource> (this IQueryable<TSource> source,
string searchKey,
MethodInfo method,
Expression<Func<TSource, string>> member,
params Expression<Func<TSource, string>>[] others) {
var parameter = GetParameterExpression (member);
var logics = member.ToSearchLambda (method, searchKey)
.Or (others.Select (m => m.ToSearchLambda (method, searchKey)).ToArray ());
logics = new ParameterReplacer (parameter).Visit (logics);
var whereExpression = Expression.Lambda<Func<TSource, bool>> (logics, false, parameter);
Debug.WriteLine (whereExpression);
//生成 .where(u=>...) 方法调用表达式
return Expression.Call (
typeof (Queryable), nameof (Queryable.Where),
new Type[] { source.ElementType },
source.Expression, whereExpression);
}
