ArcGIS Engine属性查询并加亮显示（查询结果在其他窗体中显示）

查询分为属性查询和空间查询。我现在做的是属性查询，用IQueryFilter

属性查询的基本步骤是:

1)获取要查询的图层

2）获取要素要素图层

3）获取要素集

4）用IQueryFilter进行过滤筛选

Dim pFeatureSelection As IFeatureSelection = CType(pFeatureLayer, IFeatureSelection)
Dim pQueryFilter As IQueryFilter = New QueryFilterClass()
pQueryFilter.WhereClause = (TypeComboBox.Text + TextBox1.Text)
pFeatureSelection.SelectFeatures(pQueryFilter, esriSelectionResultEnum.esriSelectionResultNew, False)

 

5）要将筛选出的要素集显示在数据表中，用ICursor和IFeatureCursor对每个要素进行遍历

    在这里谈一下个人对ICursor和IFeatureCursor的理解。ICursor主要是针对所有的类型的行进行的操作，而IFeatureCursor则主要是针对地图的要素进行的操作。ICursor是IFeatureCursor的父类。

Dim pCursor As ICursor = Nothing
pSelectionSet.Search(Nothing, True, pCursor) '找所有满足查询过滤器的行，返回一个ICursor。这是Nothing，所有返回了所有行。
Dim pFeatureCursor As IFeatureCursor = CType(pCursor, IFeatureCursor)
Dim pFeature As IFeature
pFeature = pFeatureCursor.NextFeature

6）将各元素依次赋值给datatable，以datatable为数据源传给datagridview

If pSelectionSet IsNot Nothing Then
            Dim dt As New DataTable
            Dim dc As DataColumn = Nothing
            For i = 1 To pFeatureLayer.FeatureClass.Fields.FieldCount
                dc = New DataColumn(pFeatureLayer.FeatureClass.Fields.Field(i - 1).Name)
                dt.Columns.Add(dc)
            Next

                Dim dr As DataRow
            While (pFeature IsNot Nothing)
                Dim pGeometry As IGeometry
                pGeometry = pFeature.Shape
                Dim obj As Object = Nothing
                My.Forms.MainForm.AxMapControl1.FlashShape(pGeometry, 3, 400, obj)
                dr = dt.NewRow
                Dim j As Integer
                For j = 0 To pFeature.Fields.FieldCount - 1 Step 1
                    If pFeatureLayer.FeatureClass.FindField(pFeatureLayer.FeatureClass.ShapeFieldName) = j Then
                        dr(j) = pFeatureLayer.FeatureClass.ShapeType.ToString()
                    Else
                        dr(j) = pFeature.Value(j).ToString()
                    End If
                Next
                dt.Rows.Add(dr)
                pFeature = pFeatureCursor.NextFeature()
            End While
            DataGridView1.DataSource = dt
        End If

顺便说下DataSet和DataTable的区别：

DataSet是数据集。DataTable是表。DataSet包含多个DataTable，用的时候，dataset["表名"]得到DataTable

这个终于做完啦。。。。。。