有没有一种简单的方法可以将所有对象的属性获取为字符串？

Question

I have a class called ReportToDownload that contains several properties. In the Assert part of a test I'm comparing expected and actual lists of ReportToDownload using an equality comparer I have written. For any items that don't match I was hoping to print out the contents of the expected and actual items as part of the message using:

actual[i].ToString()

but this just returns the name of the object - ReportToDownload. Is there any way of easily getting the whole contents of the object as a string?

Answer 1

Depending on who this is being shown to, a simple "no effort" solution is to use JSON:

Install-Package Newtonsoft.Json

Then...

JsonConvert.SerializeObject(actual[i])

Answer 2

Rather than using an equality comparison, write a method that compares every individual property using your unit test's framework built-in assertion methods, eg:

public void AssertEquals(ReportToDownload actual, ReportToDownload expected)
{
    Assert.That(actual.PropertyA, Is.EqualTo(expected.PropertyA));
    Assert.That(actual.PropertyB, Is.EqualTo(expected.PropertyB));
}

The built-in assertion methods will print the expected and actual values appropriately when there is a comparison failure.

Most likely, your unit test framework will also allow you to write your own assertions that will print the differences in a custom way, if necessary.

Answer 3

I don't know how useful this could be, but here's my take:

public class ClassA
{
    public string Prop1 { get; set; }
    public string Prop2 { get; set; }

    public override string ToString()
    {
        string ret = string.Empty;

        foreach (PropertyInfo pi in this.GetType().GetProperties())
        {
            ret += string.Format("{0}: {1}\r\n", pi.Name, pi.GetValue(this, null).ToString());
        }

        return ret;
    }
}

Used like this:

ClassA a = new ClassA();
a.Prop1 = "Hello";
a.Prop2 = "World";

var toStringOutput = a.ToString();

You may have to handle more complex property types, but for basic ones, that should work.