WinForms Interop，Drag&从WinForms中删除 - > WPF

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问题描述

我正在尝试将数据从Winforms部分的应用程序拖到一个包含在ElementHost的WPF控件中。当我尝试这样做时，它会崩溃。
尝试相同的东西，但从Winforms到Winforms工作正常。（见下面的示例代码）
我需要帮助来完成这项工作...有任何线索我做错了什么？
谢谢！
示例：

在下面的示例代码中， '只是试图拖动一个自定义的MyContainerClass对象，当在1）System.Windows.Forms.TextBox（Winforms）和2）System.Windows.TextBox（WPF，添加到ElementHost）时，在标签控件上启动拖动时创建的对象。
案例1）工作正常，但情况2）在尝试使用GetData（）检索丢弃数据时崩溃。 GetDataPresent（WindowsFormsApplication1.MyContainerClass）返回true，所以在理论上，我应该能够在Winforms中检索这种类型的丢弃数据。
这是崩溃的堆栈跟踪：
 
错误HRESULT E_FAIL已经通过以下堆栈跟踪从调用COM组件返回：
在System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal（Int32 errorCode，IntPtr errorInfo）
在System.Windows.Forms.DataObject .GetDataIntoOleStructs（FORMATETC&formatetc，STGMEDIUM&medium）
在System.Windows.Forms.DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetDataHere（FORMATETC&formatetc，STGMEDIUM&medium）
在System.Windows.Forms .DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetData（FORMATETC&formatetc，STGMEDIUM&medium）
在System.Windows.DataObject.OleConverter.GetDataInner（FORMATETC&formatetc，STGMEDIUM&medium）
在System.Windows .DataObject.OleConverter.GetDataFromOleHGLOBAL（String format，DVASPECT aspect，Int32 index）
在System.Windows.DataObject.OleConverter.GetDataFromBoundOleDataObject（String forma t，DVASPECT方面，Int32索引）
在System.Windows.DataObject.OleConverter.GetData（String格式，Boolean autoConvert，DVASPECT方面，Int32索引）
在System.Windows.DataObject.OleConverter.GetData（字符串格式，Boolean autoConvert）
在System.Windows.DataObject.GetData（String format，Boolean autoConvert）
在System.Windows.DataObject.GetData（字符串格式）
在WindowsFormsApplication1.Form1。 WindowsFormsApplication1\WindowsFormsApplication1\Form1.cs中的textBox_PreviewDragEnter（Object sender，DragEventArgs e）$ 48 
 $ / pre 
 
 这是一些代码： p> 
 
 
  //  - 向您的表单添加ElementHost  -  
 //  - 在表单中添加标签 - 
 
 public partial class Form1：Form 
 {
 public Form1（）
 {
 InitializeComponent（）; 
 
 System.Windows.Controls.TextBox textBox = new System.Windows.Controls.TextBox（）; 
 textBox.Text =WPF TextBox; 
 textBox.AllowDrop = true; 
 elementHost2.Child = textBox; 
 textBox.PreviewDragEnter + = new System.Windows.DragEventHandler（textBox_PreviewDragEnter）; 
 
 System.Windows.Forms.TextBox wfTextBox = new System.Windows.Forms.TextBox（）; 
 wfTextBox.Text =Winforms TextBox; 
 wfTextBox.AllowDrop = true; 
 wfTextBox.DragEnter + = new DragEventHandler（wfTextBox_DragEnter）; 
 Controls.Add（wfTextBox）; 
} 
 
 void wfTextBox_DragEnter（object sender，DragEventArgs e）
 {
 bool dataPresent = e.Data.GetDataPresent（WindowsFormsApplication1.MyContainerClass）; 
 
 // NO CRASH here！ 
 object data = e.Data.GetData（WindowsFormsApplication1.MyContainerClass）; 
} 
 
 void textBox_PreviewDragEnter（object sender，System.Windows.DragEventArgs e）
 {
 bool dataPresent = e.Data.GetDataPresent（WindowsFormsApplication1.MyContainerClass） ; 
 
 // Crash appens here！ 
 // {HRESULT E_FAIL已从对COM组件的调用返回。
对象数据= e.Data.GetData（WindowsFormsApplication1.MyContainerClass）; 
} 
 
 private void label1_MouseDown（object sender，MouseEventArgs e）
 {
 label1.DoDragDrop（new MyContainerClass（label1.Text），DragDropEffects.Copy）; 
} 
} 
 
 public class MyContainerClass 
 {
 public object Data {get;组; 
 
 public MyContainerClass（object data）
 {
 Data = data; 
} 
} 
  
 
 
解决方案
 Pedery& jmayor：谢谢你们的建议！ （见下面的发现）
 
 
 经过不少试验，试验和错误，还有一点反射器，我设法弄清楚为什么我是接收到隐含错误消息错误HRESULT E_FAIL已从对COM组件的调用返回。
 
 
 这是因为当拖动数据WPF时 - > Winforms在同一个应用程序中，数据必须可序列化！
 
 
 我已经检查了将我们所有的类到可序列化，我会有一个真正的痛苦有几个原因...一个，我们需要实际上使所有的类可序列化和两个，其中一些类有引用控件！控件不可序列化。因此，需要重构  。
 
 
 所以...因为我们想通过任何对象任何类在同一个应用程序中拖动到WPF，我决定用Serializable属性创建一个包装类，并实现ISerializable。我将有1个参数，其中1个参数类型为object，这将是实际的拖动数据。这个包装器，当序列化/解串行化时，不会将对象本身序列化，而是将对象的IntPtr序列化（我们可以做的只是在我们的1个实例应用程序中只需要该功能）。请参见下面的代码示例： 
  [Serializable] 
 public class DataContainer：ISerializable 
 {
 public object Data {get ;组; 
 
 public DataContainer（object data）
 {
 Data = data; 
} 
 
 //反序列化构造函数
 protected DataContainer（SerializationInfo info，StreamingContext context）
 {
 IntPtr address =（IntPtr）info.GetValue（ dataAddress，typeof（IntPtr））; 
 GCHandle handle = GCHandle.FromIntPtr（address）; 
 Data = handle.Target; 
 handle.Free（）; 
} 
 
 #region ISerializable成员
 
 public void GetObjectData（SerializationInfo info，StreamingContext context）
 {
 GCHandle handle = GCHandle.Alloc （数据）; 
 IntPtr address = GCHandle.ToIntPtr（handle）; 
 info.AddValue（dataAddress，address）; 
} 
 
 #endregion 
} 
  
保持IDataObject功能，我创建了以下DataObject包装器：
  public class DataObject：IDataObject 
 {
 System.Collections.Hashtable _Data = new System.Collections.Hashtable（）; 
 
 public DataObject（）{} 
 
 public DataObject（object data）
 {
 SetData（data）; 
} 
 
 public DataObject（字符串格式，对象数据）
 {
 SetData（format，data）; 
} 
 
 #region IDataObject成员
 
 public object GetData（Type format）
 {
 return _Data [format.FullName]; 
} 
 
 public bool GetDataPresent（Type format）
 {
 return _Data.ContainsKey（format.FullName）; 
} 
 
 public string [] GetFormats（）
 {
 string [] strArray = new string [_Data.Keys.Count]; 
 _Data.Keys.CopyTo（strArray，0）; 
 return strArray; 
} 
 
 public string [] GetFormats（bool autoConvert）
 {
 return GetFormats（）; 
} 
 
 private void SetData（对象数据，字符串格式）
 {
 object obj = new DataContainer（data）; 
 
 if（string.IsNullOrEmpty（format））
 {
 //创建一个虚拟DataObject对象来检索所有可能的格式。 
 //例如：对于System.String类型，GetFormats返回3种格式：
 //System.String，UnicodeText和Text
 System.Windows.Forms。 DataObject dataObject = new System.Windows.Forms.DataObject（data）; 
 foreach（dataObject.GetFormats（）中的字符串fmt）
 {
 _Data [fmt] = obj; 
} 
} 
 else 
 {
 _Data [format] = obj; 
} 
} 
 
 public void SetData（object data）
 {
 SetData（data，null）; 
} 
 
 #endregion 
} 
  
我们正在使用以下类：
  myControl.DoDragDrop（new MyNamespace.DataObject（myNonSerializableObject））; 
 
 //在drop事件中，例如
 e.Data.GetData（typeof（myNonSerializableClass））; 
  
我知道我知道...这不是很好的 但它正在做我们想要的。我们还创建了一个dragdrop帮助器类，它掩盖了DataObject的创建，并具有模板化的GetData函数来检索数据，而没有任何转换...有点像：
 code> myNonSerializableClass newObj = DragDropHelper.GetData< myNonSerializableClass>（e.Data）; 
  
所以再次感谢回复！你们给了我很好的想法，看看可能的解决方案！
 
 
  -Oli 
 
I'm trying to drag data from the Winforms portion of my application on a WPF controls that's contained inside an "ElementHost". And it crashes when I try doing so.
Trying the same thing but from Winforms to Winforms works fine. (See example code below)
I need help on making this work... have any clues what I'm doing wrong?
Thanks!
Example:
In the sample code below, I'm just trying to drag a custom MyContainerClass object created when initating the drag on the label control on a 1) System.Windows.Forms.TextBox (Winforms) and 2) System.Windows.TextBox (WPF, added to an ElementHost).  
Case 1) works fine but case 2) is crashing when trying to retrieve the drop data using GetData(). GetDataPresent("WindowsFormsApplication1.MyContainerClass") returns "true" so In theory, I should be able to retrive my drop data of that type like in Winforms.  
Here is the stack trace of the crash:  
"Error HRESULT E_FAIL has been returned from a call to a COM component" with the following stack trace:
 at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo)
 at System.Windows.Forms.DataObject.GetDataIntoOleStructs(FORMATETC& formatetc, STGMEDIUM& medium)
 at System.Windows.Forms.DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetDataHere(FORMATETC& formatetc, STGMEDIUM& medium)
 at System.Windows.Forms.DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetData(FORMATETC& formatetc, STGMEDIUM& medium)
 at System.Windows.DataObject.OleConverter.GetDataInner(FORMATETC& formatetc, STGMEDIUM& medium)
 at System.Windows.DataObject.OleConverter.GetDataFromOleHGLOBAL(String format, DVASPECT aspect, Int32 index)
 at System.Windows.DataObject.OleConverter.GetDataFromBoundOleDataObject(String format, DVASPECT aspect, Int32 index)
 at System.Windows.DataObject.OleConverter.GetData(String format, Boolean autoConvert, DVASPECT aspect, Int32 index)
 at System.Windows.DataObject.OleConverter.GetData(String format, Boolean autoConvert)
 at System.Windows.DataObject.GetData(String format, Boolean autoConvert)
 at System.Windows.DataObject.GetData(String format)
 at WindowsFormsApplication1.Form1.textBox_PreviewDragEnter(Object sender, DragEventArgs e) in WindowsFormsApplication1\WindowsFormsApplication1\Form1.cs:line 48
Here is some code:
// -- Add an ElementHost to your form --
// -- Add a label to your form --

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        System.Windows.Controls.TextBox textBox = new System.Windows.Controls.TextBox();
        textBox.Text = "WPF TextBox";
        textBox.AllowDrop = true;
        elementHost2.Child = textBox;
        textBox.PreviewDragEnter += new System.Windows.DragEventHandler(textBox_PreviewDragEnter);

        System.Windows.Forms.TextBox wfTextBox = new System.Windows.Forms.TextBox();
        wfTextBox.Text = "Winforms TextBox";
        wfTextBox.AllowDrop = true;
        wfTextBox.DragEnter += new DragEventHandler(wfTextBox_DragEnter);
        Controls.Add(wfTextBox);
    }

    void wfTextBox_DragEnter(object sender, DragEventArgs e)
    {
        bool dataPresent = e.Data.GetDataPresent("WindowsFormsApplication1.MyContainerClass");

        // NO CRASH here!
        object data = e.Data.GetData("WindowsFormsApplication1.MyContainerClass");
    }

    void textBox_PreviewDragEnter(object sender, System.Windows.DragEventArgs e)
    {
        bool dataPresent = e.Data.GetDataPresent("WindowsFormsApplication1.MyContainerClass");

        // Crash appens here!!
        // {"Error HRESULT E_FAIL has been returned from a call to a COM component."}
        object data = e.Data.GetData("WindowsFormsApplication1.MyContainerClass");
    }

    private void label1_MouseDown(object sender, MouseEventArgs e)
    {
        label1.DoDragDrop(new MyContainerClass(label1.Text), DragDropEffects.Copy);
    }
}

public class MyContainerClass
{
    public object Data { get; set; }

    public MyContainerClass(object data)
    {
        Data = data;
    }
}
 解决方案 
@Pedery & jmayor: Thanks for the suggestions guys! (see my findings below)
After quite a few experimentation, trials and errors, and a bit of "Reflector'ing", I managed to figure out exactly why I was receiving the cryptic error message "Error HRESULT E_FAIL has been returned from a call to a COM component".
It was due to the fact that when dragging data WPF <-> Winforms in a same app, that data has to be Serializable!
I've checked how difficult it would be to transform all of our classes to "Serializable" and I would have a been a real pain for a couple of reasons... one, we would need to practically make all of classes serializable and two, some of these classes have references to Controls! And Controls aren't serializable. So a major refactoring would have been needed.
So... since we wanted to pass any object of any class to drag from/to WPF inside the same application, I decided to create a wrapper class, with the Serializable attribute and implementing ISerializable. I would have 1 contructor with 1 parameter of type "object" which would be the actual drag data. That wrapper, when serializing/de-serializing, would serialize not the object itself... but rather the IntPtr to the object (which we can do since we only want that functionnality inside our 1 instance only application.) See code sample below:
[Serializable]
public class DataContainer : ISerializable
{
public object Data { get; set; }

public DataContainer(object data)
{
    Data = data;
}

// Deserialization constructor
protected DataContainer(SerializationInfo info, StreamingContext context)
{
    IntPtr address = (IntPtr)info.GetValue("dataAddress", typeof(IntPtr));
    GCHandle handle = GCHandle.FromIntPtr(address);
    Data = handle.Target;
    handle.Free();
}

#region ISerializable Members

public void GetObjectData(SerializationInfo info, StreamingContext context)
{
    GCHandle handle = GCHandle.Alloc(Data);
    IntPtr address = GCHandle.ToIntPtr(handle);
    info.AddValue("dataAddress", address);
}

#endregion
}
To keep the IDataObject functionnality, I created the following DataObject wrapper:
public class DataObject : IDataObject
{
System.Collections.Hashtable _Data = new System.Collections.Hashtable();

public DataObject() { }

public DataObject(object data)
{
    SetData(data);
}

public DataObject(string format, object data)
{
    SetData(format, data);
}

#region IDataObject Members

public object GetData(Type format)
{
    return _Data[format.FullName];
}

public bool GetDataPresent(Type format)
{
    return _Data.ContainsKey(format.FullName);
}

public string[] GetFormats()
{
    string[] strArray = new string[_Data.Keys.Count];
    _Data.Keys.CopyTo(strArray, 0);
    return strArray;
}

public string[] GetFormats(bool autoConvert)
{
    return GetFormats();
}

private void SetData(object data, string format)
{
    object obj = new DataContainer(data);

    if (string.IsNullOrEmpty(format))
    {
        // Create a dummy DataObject object to retrieve all possible formats.
        // Ex.: For a System.String type, GetFormats returns 3 formats:
        // "System.String", "UnicodeText" and "Text"
        System.Windows.Forms.DataObject dataObject = new System.Windows.Forms.DataObject(data);
        foreach (string fmt in dataObject.GetFormats())
        {
            _Data[fmt] = obj;
        }
    }
    else
    {
        _Data[format] = obj;
    }
}

public void SetData(object data)
{
    SetData(data, null);
}

#endregion
}
And we are using the above classes like this: 
myControl.DoDragDrop(new MyNamespace.DataObject(myNonSerializableObject));

// in the drop event for example
e.Data.GetData(typeof(myNonSerializableClass));
I know I know... it's not very pretty... but it's doing what we wanted. We also created a dragdrop helper class which masks the DataObject creation and has templated GetData functions to retrieve the data without any cast... a bit like:
myNonSerializableClass newObj = DragDropHelper.GetData<myNonSerializableClass>(e.Data);
So thanks again for the replies! You guys gave me good ideas where to look at for possible solutions!
-Oli
                        这篇关于WinForms Interop，Drag&amp;从WinForms中删除 - &gt; WPF的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！
classes

WinForms Interop，Drag&amp;从WinForms中删除 - &gt; WPF

问题描述

WinForms Interop，Drag&从WinForms中删除 - > WPF
