Question

我试图从R调用.NET DLL文件并返回数据表。

这个Q&A显示了如何从R调用.NET，但是我可以找到有关如何返回数据的任何文档（除了像字符串这样的简单值）：

.NET方法：

public DataTable GetDatatable(string parameters)
{
    var dt = new DataTable();
    dt.Columns.Add("Dates", typeof(DateTime));
    dt.Columns.Add("Strings", typeof(String));
    dt.Columns.Add("Number", typeof(Double));

    DataRow dr = dt.NewRow();
    dr[0] = new DateTime(2014, 1, 23);
    dr[1] = "test";
    dr[2] = 123.45;

    dt.Rows.Add(dr);
    return dt;
}

里面的R：

> library(rClr)
> clrLoadAssembly('C:/Dev/Sandbox/XYZ/bin/Debug/XYZ2R.dll')
> myObj <- clrNew('XYZ2R.DAL,XYZ2R')
> res = clrCall(myObj,'GetDatatable', "parameter")
> res

班级的对象＆＃34; cobjRef＆＃34;
Slot＆＃34; clrobj＆＃34;：
＆lt; pointer：0x0027f218＆gt;

Slot＆＃34; clrtype＆＃34;：
[1]＆＃34; System.Data.DataTable＆＃34;

res [0,1]
res [0,1]中的错误：类型＆＃39; S4＆＃39;的对象不是子集的

From what I've read看来我需要传递参考资料。对参数的论证，例如：

public void Test(string parameters, params List<string>[] data)

虽然我不确定，但是没有任何从R调用.NET方法和返回列表的例子。有一些文章讨论了相反的情况。

我该怎么做？

Answer 1

使用当前发布的软件包并使用您的测试方法，以下内容正确检索项目

library(rClr)
clrLoadAssembly('c:/tmp/DataTableTest/bin/Debug/DataTableTest.dll')
obj <- clrNew('DataTableTest.Class1')
dataTable <- clrCall(obj, 'GetDatatable', '')
clrReflect(dataTable)
dv <- clrGet(dataTable, 'DefaultView')
clrReflect(dv)
getTableItem <- function(view, rowInd, colInd) {
  dataRowView <- clrCall(view, 'get_Item', as.integer(rowInd))
  clrCall(dataRowView, 'get_Item', as.integer(colInd))
}
getTableItem(dv, 0L, 0L)
getTableItem(dv, 0L, 1L)
getTableItem(dv, 0L, 2L)

在接下来的几个月里，我将进行一些语法改进;我注意到DataTable和相关类是数据帧的自然兄弟，并将尝试为它提供更简洁的语法。请随时在 ~~https://rclr.codeplex.com~~ https://github.com/jmp75/rClr

中记录详细功能请求

Answer 2

使用clrReflect方法从R检查.NET对象的方法和属性很简单：

<强>＆GT; clrReflect（dataTable中）
$方法
[1]＆＃34; AcceptChanges＆＃34; ＆＃34; add_ColumnChanged＆＃34; ＆＃34; add_ColumnChanging＆＃34; ＆＃34; add_Disposed＆＃34; ＆＃34; add_Initialized＆＃34; ＆＃34; add_RowChanged＆＃34;
[7]＆＃34; add_RowChanging＆＃34; ＆＃34; add_RowDeleted＆＃34; ＆＃34; add_RowDeleting＆＃34; ＆＃34; add_TableCleared＆＃34; ＆＃34; add_TableClearing＆＃34; ＆＃34; add_TableNewRow＆＃34;
[13]＆＃34; BeginInit＆＃34; ＆＃34; BeginLoadData＆＃34; ＆＃34;清除＆＃34; ＆＃34;克隆＆＃34; ＆＃34;计算＆＃34; ＆＃34;复印＆＃34;
[19]＆＃34; CreateDataReader＆＃34; ＆＃34;处置＆＃34; ＆＃34; EndInit＆＃34; ＆＃34; EndLoadData＆＃34; ＆＃34;的Equals＆＃34; ＆＃34; get_CaseSensitive＆＃34;
[25]＆＃34; get_ChildRelations＆＃34; ＆＃34; get_Columns＆＃34; ＆＃34; get_Constraints＆＃34; ＆＃34; get_Container＆＃34; ＆＃34; get_DataSet＆＃34; ＆＃34; get_DefaultView＆＃34;
[31]＆＃34; get_DesignMode＆＃34; ＆＃34; get_DisplayExpression＆＃34; ＆＃34; get_ExtendedProperties＆＃34; ＆＃34; get_HasErrors＆＃34; ＆＃34; get_IsInitialized＆＃34; ＆＃34; get_Locale＆＃34;
[37]＆＃34; get_MinimumCapacity＆＃34; ＆＃34; get_Namespace＆＃34; ＆＃34; get_ParentRelations＆＃34; ＆＃34; get_Prefix＆＃34; ＆＃34; get_PrimaryKey＆＃34; ＆＃34; get_RemotingFormat＆＃34;
[43]＆＃34; get_Rows＆＃34; ＆＃34; get_Site＆＃34; ＆＃34; get_TableName＆＃34; ＆＃34; GetChanges＆＃34; ＆＃34; GetChanges＆＃34; ＆＃34; GetErrors＆＃34;
[49]＆＃34; GetHashCode＆＃34; ＆＃34; GetObjectData使用＆＃34; ＆＃34; GetService的＆＃34; ＆＃34;的GetType＆＃34; ＆＃34; ImportRow＆＃34; ＆＃34;装载＆＃34;
[55]＆＃34;加载＆＃34; ＆＃34;装载＆＃34; ＆＃34; LoadDataRow＆＃34; ＆＃34; LoadDataRow＆＃34; ＆＃34;合并＆＃34; ＆＃34;合并＆＃34;
[61]＆＃34;合并＆＃34; ＆＃34; NEWROW＆＃34; ＆＃34;的ReadXml＆＃34; ＆＃34;的ReadXml＆＃34; ＆＃34;的ReadXml＆＃34; ＆＃34;的ReadXml＆＃34;
[67]＆＃34; ReadXmlSchema＆＃34; ＆＃34; ReadXmlSchema＆＃34; ＆＃34; ReadXmlSchema＆＃34; ＆＃34; ReadXmlSchema＆＃34; ＆＃34; RejectChanges＆＃34; ＆＃34; remove_ColumnChanged＆＃34;
[73]＆＃34; remove_ColumnChanging＆＃34; ＆＃34; remove_Disposed＆＃34; ＆＃34; remove_Initialized＆＃34; ＆＃34; remove_RowChanged＆＃34; ＆＃34; remove_RowChanging＆＃34; ＆＃34; remove_RowDeleted＆＃34;
[79]＆＃34; remove_RowDeleting＆＃34; ＆＃34; remove_TableCleared＆＃34; ＆＃34; remove_TableClearing＆＃34; ＆＃34; remove_TableNewRow＆＃34; ＆＃34;复位＆＃34; ＆＃34;选择＆＃34;
[85]＆＃34;选择＆＃34; ＆＃34;选择＆＃34; ＆＃34;选择＆＃34; ＆＃34; set_CaseSensitive＆＃34; ＆＃34; set_DisplayExpression＆＃34; ＆＃34; set_Locale＆＃34;
[91]＆＃34; set_MinimumCapacity＆＃34; ＆＃34; set_Namespace＆＃34; ＆＃34; set_Prefix＆＃34; ＆＃34; set_PrimaryKey＆＃34; ＆＃34; set_RemotingFormat＆＃34; ＆＃34; set_Site＆＃34;
[97]＆＃34; set_TableName＆＃34; ＆＃34;的ToString＆＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34;
[103]＆＃34; WriteXml＆＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34;
[109]＆＃34; WriteXml＆＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34; ＆＃34;＆中WriteXML＃34;
[115]＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34;
[121]＆＃34; WriteXmlSchema＆＃34; ＆＃34; WriteXmlSchema＆＃34;

$字段
character（0）

$属性
[1]＆＃34; CaseSensitive＆＃34; ＆＃34; ChildRelations＆＃34; ＆＃34;列＆＃34; ＆＃34;约束＆＃34; ＆＃34;集装箱＆＃34; ＆＃34;数据集＆＃34; ＆＃34;默认视图＆＃34; ＆＃34;的designMode＆＃34;
[9]＆＃34; DisplayExpression＆＃34; ＆＃34; ExtendedProperties＆＃34; ＆＃34; HasErrors＆＃34; ＆＃34;将IsInitialized＆＃34; ＆＃34;区域设置＆＃34; ＆＃34; MinimumCapacity＆＃34; ＆＃34;命名空间＆＃34; ＆＃34; ParentRelations＆＃34;
[17]＆＃34;前缀＆＃34; ＆＃34;的PrimaryKey＆＃34; ＆＃34; RemotingFormat＆＃34; ＆＃34;行＆＃34; ＆＃34;网站＆＃34; ＆＃34;表名＆＃34;

<强>＆GT; clrReflect（DV）
$方法
[1]＆＃34; add_Disposed＆＃34; ＆＃34; add_Initialized＆＃34; ＆＃34; add_ListChanged＆＃34; ＆＃34;的AddNew＆＃34; ＆＃34; BeginInit在＆＃34; ＆＃34; CopyTo从＆＃34; ＆＃34;删除＆＃34; ＆＃34;处置＆＃34;
[9]＆＃34; EndInit＆＃34; ＆＃34;的Equals＆＃34; ＆＃34;的Equals＆＃34; ＆＃34;查找与＃34; ＆＃34;查找与＃34; ＆＃34; FindRows＆＃34; ＆＃34; FindRows＆＃34; ＆＃34; get_AllowDelete＆＃34;
[17]＆＃34; get_AllowEdit＆＃34; ＆＃34; get_AllowNew＆＃34; ＆＃34; get_ApplyDefaultSort＆＃34; ＆＃34; get_Container＆＃34; ＆＃34; get_Count＆＃34; ＆＃34; get_DataViewManager＆＃34; ＆＃34; get_DesignMode＆＃34; ＆＃34; get_IsInitialized＆＃34;
[25]＆＃34; get_Item＆＃34; ＆＃34; get_RowFilter＆＃34; ＆＃34; get_RowStateFilter＆＃34; ＆＃34; get_Site＆＃34; ＆＃34; get_Sort＆＃34; ＆＃34; get_Table＆＃34; ＆＃34;的GetEnumerator＆＃34; ＆＃34;的GetHashCode＆＃34;
[33]＆＃34; GetService＆＃34; ＆＃34;的GetType＆＃34; ＆＃34; remove_Disposed＆＃34; ＆＃34; remove_Initialized＆＃34; ＆＃34; remove_ListChanged＆＃34; ＆＃34; set_AllowDelete＆＃34; ＆＃34; set_AllowEdit＆＃34; ＆＃34; set_AllowNew＆＃34;
[41]＆＃34; set_ApplyDefaultSort＆＃34; ＆＃34; set_RowFilter＆＃34; ＆＃34; set_RowStateFilter＆＃34; ＆＃34; set_Site＆＃34; ＆＃34; set_Sort＆＃34; ＆＃34; set_Table＆＃34; ＆＃34;的ToString＆＃34; ＆＃34; ToTable＆＃34;
[49]＆＃34; ToTable＆＃34; ＆＃34; ToTable＆＃34; ＆＃34; ToTable＆＃34;

$字段
character（0）

$属性
[1]＆＃34; AllowDelete＆＃34; ＆＃34; AllowEdit＆＃34; ＆＃34; AllowNew＆＃34; ＆＃34; ApplyDefaultSort＆＃34; ＆＃34;集装箱＆＃34; ＆＃34;计数＆＃34; ＆＃34;的DataViewManager＆＃34; ＆＃34;的designMode＆＃34; ＆＃34;将IsInitialized＆＃34; ＆＃34;项目＆＃34; ＆＃34;的RowFilter＆＃34; ＆＃34; RowStateFilter＆＃34; ＆＃34;网站＆＃34; ＆＃34;分类＆＃34; ＆＃34;表＆＃34;

要调用方法，请使用clrCall（dotNetObject，＆＃39; MethodName＆＃39;）

要查看属性，请使用clrGet（dotNetObject，＆＃39; PropertyName＆＃39;）

例如，让我们算出返回的DataTable中的行数   来自GetDatatable方法：

<强>＆GT; clrCall（DV，＆＃39; get_Count＆＃39）
[1] 2

现在让我们计算出列数：

<强>＆GT; clrGet（dataTable中，＆＃39;列＆＃39）
上课的对象＆＃34; cobjRef＆＃34;
Slot＆＃34; clrobj＆＃34;：

Slot＆＃34; clrtype＆＃34;：
[1]＆＃34; System.Data.DataColumnCollection＆＃34;

<强>＆GT; cols＆lt; - clrGet（dataTable，＆＃39; Columns＆＃39;）
的＆GT; clrReflect（COLS）
$方法
[1]＆＃34;添加＆＃34; ＆＃34;添加＆＃34; ＆＃34;添加＆＃34; ＆＃34;添加＆＃34; ＆＃34;添加＆＃34; ＆＃34; add_CollectionChanged＆＃34;
[7]＆＃34; AddRange＆＃34; ＆＃34; CanRemove＆＃34; ＆＃34;清除＆＃34; ＆＃34;包含＆＃34; ＆＃34; CopyTo从＆＃34; ＆＃34; CopyTo从＆＃34;
[13]＆＃34;等于＆＃34; ＆＃34; get_Count＆＃34; ＆＃34; get_IsReadOnly＆＃34; ＆＃34; get_IsSynchronized＆＃34; ＆＃34; get_Item＆＃34; ＆＃34; get_Item＆＃34;
[19]＆＃34; get_SyncRoot＆＃34; ＆＃34;的GetEnumerator＆＃34; ＆＃34;的GetHashCode＆＃34; ＆＃34;的GetType＆＃34; ＆＃34;的IndexOf＆＃34; ＆＃34;的IndexOf＆＃34;
[25]＆＃34;删除＆＃34; ＆＃34;删除＆＃34; ＆＃34; remove_CollectionChanged＆＃34; ＆＃34; RemoveAt移除＆＃34; ＆＃34;的ToString＆＃34;

$字段
character（0）

$属性
[1]＆＃34;伯爵＆＃34; ＆＃34; IsReadOnly＆＃34; ＆＃34; IsSynchronized＆＃34; ＆＃34;项目＆＃34; ＆＃34;项目＆＃34; ＆＃34; SyncRoot上＆＃34;

<强>＆GT; clrGet（COLS，＆＃39;计数＆＃39）
[1] 26

从C＃/ .NET返回数据表到R

2 个答案: