Generic methods to get configuration values

For some reason, there are things in code that I just cannot remember. One of these things is getting values from configuration – web.config or app.config.

Yes, I know, it is ridiculous. I remember literally hundreds of classes and methods, but a simple, one-line “ConfigurationManager.AppSettings[key]” I have to google. So I just gave up and wrote a wrapper – and to make it a bit more useful, I did a generic version, which can get the configuration value already in a specified type.

So, here is the three-method class, imaginatively named “Config”:

1. /// <summary>
2. /// Shorthand class for easy access to web.config values
3. /// </summary>
4. public static class Config
5. {
6.  
7.     /// <summary>
8.     /// Gets the setting as string by key.
9.     /// Return string.Empty if the key does not exist
10.     /// </summary>
11.     /// <param name="key">The key.</param>
12.     /// <returns></returns>
13.     public static string GetSettingByKey(string key)
14.     {
15.         return ConfigurationManager.AppSettings[key] ?? string.Empty;
16.     }
17.  
18.     /// <summary>
19.     /// Generic version of GetSettingByKey().
20.     /// Returns default(T) if the key does not exist
21.     /// </summary>
22.     /// <typeparam name="T"></typeparam>
23.     /// <param name="key">The key.</param>
24.     /// <returns></returns>
25.     public static T GetSettingByKey<T>(string key)
26.     {
27.         var value = ConfigurationManager.AppSettings[key];
28.  
29.         return string.IsNullOrWhiteSpace(value) ? default(T) : (T)(object)(value);
30.     }
31.  
32.     /// <summary>
33.     /// Returns defaultValue, if the key does not exist.
34.     /// </summary>
35.     /// <typeparam name="T"></typeparam>
36.     /// <param name="key">The key.</param>
37.     /// <param name="defaultValue">The default value.</param>
38.     /// <returns></returns>
39.     public static T GetSettingByKey<T>(string key, T defaultValue)
40.     {
41.         var value = ConfigurationManager.AppSettings[key];
42.  
43.         return string.IsNullOrWhiteSpace(value) ? defaultValue : (T)(object)(value);
44.     }
45. }

Use it simply Config.GetSettingByKey<int>(“RowCount”) – which would return 0, if the key “RowCount” doesn’t exist. Use Config.GetSettingByKey<int>(“RowCount”, 16) to specify a different default value.

You could also do separate properties for more frequently used configuration values, to avoid typos in string keys:

1. public static DateTime MyDateTime
2. {
3.     get { return GetSettingByKey<DateTime>("MyDateTime", DateTime.Now); }
4. }

About these ads