Question

对于我的应用程序设置中的每个项目，我在其Description Property中添加了文本，我想在运行时检索它。我确信我在这里缺少一些基本的逻辑细微差别，但我尝试过的一切都失败了。显然，我对需要传递给SettingsProperty类的Attributes属性的值的理解是错误的。我进一步感到困惑的是，当我遍历SettingsProperty.Attributes.Keys返回的所有键时，我可以看到“System.Configuration.SettingsDescriptionAttribute”，但是当我将该字符串作为键传递给Attributes属性时，返回null。

如何正确检索值描述属性的任何见解将非常感激。谢谢。：）

public void MyMethod()
    {
        SettingsPropertyCollection MyAppProperties = 
            Properties.Settings.Default.Properties;

        IEnumerator enumerator = MyAppProperties.GetEnumerator();

        // Iterate through all the keys to see what we have....
        while (enumerator.MoveNext())
        {
            SettingsProperty property = (SettingsProperty)enumerator.Current;
            ICollection myKeys = property.Attributes.Keys;

            foreach (object theKey in myKeys)
                System.Diagnostics.Debug.Print(theKey.ToString());
                // One of the keys returned is: 
                   System.Configuration.SettingsDescriptionAttribute
        }

        enumerator.Reset();

        while (enumerator.MoveNext())
        {
            SettingsProperty property = (SettingsProperty)enumerator.Current;

            string propertyValue = property.DefaultValue.ToString();

            // This fails: Null Reference 
            string propertyDescription = 
                property.Attributes["System.Configuration.SettingsDescriptionAttribute"].ToString();

            // Do stuff with strings...
        }
    }

Answer 1

此代码显示了所有具有说明的设置：

using System;
using System.Configuration;
using System.Reflection;

namespace ConsoleApplication1 {
  class Program {
    static void Main(string[] args) {
      var all = typeof(Properties.Settings).GetProperties();
      foreach (var prop in all) {
        var attr = (SettingsDescriptionAttribute[])prop.GetCustomAttributes(typeof(SettingsDescriptionAttribute), false);
        if (attr.Length > 0) 
          Console.WriteLine("{0}: {1}", prop.Name, attr[0].Description);
      }
      Console.ReadLine();
    }
  }
}

Answer 2

您尝试通过其密钥从HashTable获取值，但是您使用了错误的密钥。（我猜哈希表使用属性本身的哈希值作为键）

对代码的此更改演示了：

    public void MyMethod()
    {
        SettingsPropertyCollection MyAppProperties = 
            Properties.Settings.Default.Properties;

        IEnumerator enumerator = MyAppProperties.GetEnumerator();

        // Iterate through all the keys to see what we have....
        while (enumerator.MoveNext())
        {
            SettingsProperty property = (SettingsProperty)enumerator.Current;
            ICollection myKeys = property.Attributes.Keys;

            foreach (object theKey in myKeys)
            {
                if (property.Attributes[theKey].GetType().Name == "SettingsDescriptionAttribute")
                {
                    SettingsDescriptionAttribute sda = property.Attributes[theKey] as SettingsDescriptionAttribute;
                    System.Diagnostics.Debug.Print(sda.Description); // prints the description
                }
            }
        }

    }

Answer 3

问题是Attributes []索引器中的键不带字符串。

试试这个：

    public void MyMethod()
    {
        SettingsPropertyCollection MyAppProperties =
            Properties.Settings.Default.Properties;

        IEnumerator enumerator = MyAppProperties.GetEnumerator();
        object settingsDescriptionAttribute = null;

        // Iterate through all the keys to see what we have.... 
        while (enumerator.MoveNext())
        {
            SettingsProperty property = (SettingsProperty)enumerator.Current;
            ICollection myKeys = property.Attributes.Keys;

            foreach (object theKey in myKeys)
            {
                System.Diagnostics.Debug.Print(theKey.ToString());
                if (theKey.ToString() == "System.Configuration.SettingsDescriptionAttribute")
                    settingsDescriptionAttribute = theKey;
            }
        }

        enumerator.Reset();

        while (enumerator.MoveNext())
        {
            SettingsProperty property = (SettingsProperty)enumerator.Current;

            string propertyValue = property.DefaultValue.ToString();

            // This fails: Null Reference  
            string propertyDescription =
                property.Attributes[settingsDescriptionAttribute].ToString();

            // Do stuff with strings... 
        }
    }

如何从SettingsProperty中检索Description属性？

3 个答案: