public static Expression <Func <T, bool> > GetExpressions(T t)
{
ParameterExpression u = Expression.Parameter(typeof(T), "u");
Filter filterObj = new Filter();
filterObj.Key = "";
filterObj.Value = "";
// 获得此模型的类型
Type type = typeof(T);
Expression result = Expression.Constant(true);
// 获得此模型的公共属性
PropertyInfo[] propertys = t.GetType().GetProperties();
for (int i = 0; i < propertys.Length; i++)
{
Object value2 = propertys[i].GetValue(t, null);
if (value2 != null && value2.ToString() != "")
{
filterObj.Key = propertys[i].Name.ToString();
if (propertys[i].PropertyType == typeof(DateTime) || propertys[i].PropertyType == typeof(DateTime?))
{
filterObj.Value = ((DateTime)propertys[i].GetValue(t, null)).ToString("yyyy-MM-dd HH:mm:ss.fff");
}
else
{
filterObj.Value = propertys[i].GetValue(t, null).ToString();
}
if (
(propertys[i].PropertyType == typeof(int) || propertys[i].PropertyType == typeof(int?)) ||
(propertys[i].PropertyType == typeof(short) || propertys[i].PropertyType == typeof(short?)) ||
(propertys[i].PropertyType == typeof(long) || propertys[i].PropertyType == typeof(long?)) ||
(propertys[i].PropertyType == typeof(decimal) || propertys[i].PropertyType == typeof(decimal?)) ||
(propertys[i].PropertyType == typeof(double) || propertys[i].PropertyType == typeof(double?)) ||
(propertys[i].PropertyType == typeof(bool) || propertys[i].PropertyType == typeof(bool?))
)
{
filterObj.Contrast = ConvertOperString("eq");
filterObj.JqContrast = "eq";
if (propertys[i].PropertyType == typeof(int?) ||
propertys[i].PropertyType == typeof(short?) ||
propertys[i].PropertyType == typeof(long?) ||
propertys[i].PropertyType == typeof(double?) ||
propertys[i].PropertyType == typeof(bool?)
)
{
PropertyInfo property = typeof(T).GetProperty(filterObj.Key);
Expression left = Expression.Property(u, property);
try
{
result = result.AndAlso(Expression.Property(left, "HasValue"));
}
catch (Exception ex)
{
throw ex;
}
}
}
else
{
filterObj.Contrast = ConvertOperString("cn");
filterObj.JqContrast = "cn";
}
result = result.AndAlso(u.GenerateBody <T>(filterObj));
}
}
Expression <Func <T, bool> > expression = u.GenerateTypeLambda <T>(result);
return(expression);
}