c# - 使用反射设置类实例的字段

Question

我有以下与反射相关的问题，我有一个看起来像这样的方法:

  [TestMethod()]
 public void steamAccess()
        {
            testRead = new TestRead();
            SteamMap a = new SteamMap();

           // Preparing the parameters of the CSV actions
            a.writeMessageParams.UIItemEditText = TestContext.DataRow["SearchQuery"].ToString();

           //Read and Execute the TestMethod
            testRead.Read(a, TestContext);
        }

这是一个CodedUITest，SteamMap是一个类(uiTest map)。WriteMessageParams 是一个类，实际上真正的方法是 WriteMessage 但是这个类允许我覆盖 WriteMessage 在我的测试中使用的字符串方法，我计划在 Read 方法中使这部分代码更加动态。 :

   a.writeMessageParams.UIItemEditText = TestContext.DataRow["SearchQuery"].ToString();

我的问题发生在 testRead.Read 上下文中，如下所示:

当这个方法运行时，我可以访问来自相应实例的所有操作(在我的例子中是 a )，如果他们应该必须使用 a.writeMessageParams.UIItemEditText context 我知道，我如何获取信息不是问题，问题是如何使前面提到的代码像我尝试的那样动态运行:

/* I've done this because I know that each method that is supposed to end up with Params, for example a method called WriteMessage, it's class is called WriteMessageParams*/

public void Read(object obj, TestContext testContext)
{
//simplified code
//trying to access/get to the current instance's WriteMessageParam class 
Object testObj = obj.GetType().GetMember(subMethod.Code + "Param");

//null
MessageBox.Show(testObj.GetType().ToString());

// trying to access the UIItemEditText field ( which is declared as public) and modify it accordingly 
FieldInfo subMethodField = testObj.GetType().GetField("UIItemEditText");
subMethodField.SetValue(testObj,testContext.DataRow[subMethod.CsvColumn].ToString());
}

我已经阅读了这篇文章并尝试了一些东西 https://msdn.microsoft.com/en-us/library/6z33zd7h%28v=vs.110%29.aspx

我的问题是我有一个实例的对象，我试图访问这个对象的类并修改那个类的字段。

如果有任何帮助，我将不胜感激，谢谢

编辑 1:这就是我尝试访问的类的样子:

public partial class SteamMap
    { //simplified to what classes/methods interest me

            public virtual writeMessageParams writeMessageParams
        {
            get
            {
                if ((this.mwriteMessageParams == null))
                {
                    this.mwriteMessageParams = new writeMessageParams();
                }
                return this.mwriteMessageParams;
            }
        }

public class writeMessageParams
    {

        #region Fields
        /// <summary>
        /// Type 'test' in text box
        /// </summary>
        public string UIItemEditText = "test";
        #endregion
    }
    }

编辑 2 - 我已经尝试使用 GetNestedType，但仍然没有成功....

Object testObj = obj.GetType().GetNestedType("writeMessageParams",BindingFlags.Public);
 MessageBox.Show(testObj.GetType().ToString());

Answer 1

如果我理解你的话，你有一个类似的类

public partial class SteamMap
{  

    private writeMessageParams mwriteMessageParams ;

    public virtual writeMessageParams  writeMessageParams1
    {
        get
        {
            if ((this.mwriteMessageParams == null))
            {
                this.mwriteMessageParams = new writeMessageParams();
            }
            return this.mwriteMessageParams;
        }
    }

    public class writeMessageParams
    {            
        public string UIItemEditText = "test";       
    }
}

(您的代码无法编译，因为您将 writeMessageParams 作为类和属性，所以我已将属性更改为 writeMessageParams1)

并且您想更改 UIItemEditText，您可以这样做

public void UpdateUI(object obj, string newValue)
{
    var property = obj.GetType().GetProperty("writeMessageParams1");

    var writeMessageParams1 = property.GetValue(obj);


    var uiFld = wp.GetType().GetField("UIItemEditText");

    uiFld.SetValue(writeMessageParams1, newValue);

}

可以这样称呼

SteamMap sm = new SteamMap();
Write(sm, "Hello");  

关键是对属性使用.GetProperty，对字段使用.GetField。