Dynamically getting/setting a property of an object in C# 2005

Question

I've inherited a code base and I'm writing a little tool to update a database for it. The code uses a data access layer like SubSonic (but it is home-grown). There are many properties of an object, like "id", "templateFROM" and "templateTO", but there are 50 of them.

On screen, I can't display all 50 properties each in their own textbox for data entry, so I have a listbox of all the possible properties, and one textbox for editing. When they choose a property in the listbox, I fill the textbox with the value that property corresponds to. Then I need to update the property after they are done editing.

Right now I'm using 2 huge switch case statements. This seems stupid to me. Is there a way to dynamically tell C# what property I want to set or get? Maybe like:

entObj."templateFROM" = _sVal;

??

Answer 1

You need to use System.Reflection for that task.

entObj.GetType().GetProperty("templateFROM").SetValue(entObj, _sVal, null);

This should help you.

Answer 2

What you want is called reflection.

Answer 3

PropertyInfo[] properties = typeof(YourClass).GetProperties(BindingFlags.Instance | BindingFlags.Public)

you can bind this to your drop down list, and later on:

PropertyInfo property = typeof(YourClass).GetProperty(propertyName, BindingFlags.Instance | BindingFlags.Public)
property.SetValue(class, textBox.Text, null);

Answer 4

I think what you're looking for is Reflection. Here's a little snippet:

Type t = entObj.GetType();
t.GetProperty("templateFROM").SetValue(entObj, "new value", null);

On more of a usability note (and less of an answering-your-question note), you might want to look into using a PropertyGrid control. That listbox/textbox sounds like it could be pretty tedious to use.

Answer 5

This sample helpful

public class aa
{
    private string myVar;

    public string value
    {
        get { return myVar; }
        set { myVar = value; }
    }   
}



private void button1_Click(object sender, EventArgs e)
    {
        aa a1 = new aa();
        System.Reflection.PropertyInfo pt = typeof(aa).GetProperty("value");
        pt.SetValue(a1, "hi",null);
        this.Text = a1.value;
    }

Answer 6

On a related note, you're users will hate this interface if they need to update a lot of properties at once. Can you divide the properties into groups or pages that the user can move through more quickly?