Arcenginee鼠标控制框选一个区域

您好！如果您想在 ArcEngine 中通过鼠标控制框选一个区域，可以按照以下步骤进行操作：

1. 在地图控件上注册 MouseDown、MouseMove 和 MouseUp 事件：

private void axMapControl1_OnMouseDown(object sender, IMapControlEvents2_OnMouseDownEvent e)
{
    if (e.button == 1) // 如果是左键按下
    {
        isDragging = true;
        startX = e.mapX;
        startY = e.mapY;
    }
}

private void axMapControl1_OnMouseMove(object sender, IMapControlEvents2_OnMouseMoveEvent e)
{
    if (isDragging)
    {
        endX = e.mapX;
        endY = e.mapY;
        DrawRectangle();
    }
}

private void axMapControl1_OnMouseUp(object sender, IMapControlEvents2_OnMouseUpEvent e)
{
    if (isDragging)
    {
        endX = e.mapX;
        endY = e.mapY;
        isDragging = false;
        DrawRectangle();
        SelectFeatures();
    }
}

其中，isDragging 表示当前鼠标是否正在拖动，startX、startY 表示拖动起点的坐标，endX、endY 表示拖动终点的坐标，DrawRectangle() 方法用于绘制矩形框，SelectFeatures() 方法用于选中框选区域内的要素。

2. 编写 DrawRectangle() 方法：

private void DrawRectangle()
{
    IGraphicsContainer graphicsContainer = (IGraphicsContainer)axMapControl1.Map;
    IActiveView activeView = (IActiveView)axMapControl1.Map;
    graphicsContainer.DeleteAllElements();
    IRectangleElement rectangleElement = new RectangleElementClass();
    IElement element = (IElement)rectangleElement;
    element.Geometry = new EnvelopeClass() { XMin = Math.Min(startX, endX), YMin = Math.Min(startY, endY), XMax = Math.Max(startX, endX), YMax = Math.Max(startY, endY) };
    ISimpleFillSymbol fillSymbol = new SimpleFillSymbolClass() { Color = new RgbColorClass() { Red = 255 } };
    ISimpleLineSymbol lineSymbol = new SimpleLineSymbolClass() { Color = new RgbColorClass() { Green = 255 }, Width = 2 };
    rectangleElement.Symbol = fillSymbol;
    rectangleElement.Symbol.Border = lineSymbol;
    graphicsContainer.AddElement(element, 0);
    activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
}

该方法主要实现了绘制矩形框的功能，使用了 IGraphicsContainer、IActiveView、IRectangleElement、ISimpleFillSymbol 和 ISimpleLineSymbol 接口。

3. 编写 SelectFeatures() 方法：

private void SelectFeatures()
{
    IEnvelope envelope = new EnvelopeClass() { XMin = Math.Min(startX, endX), YMin = Math.Min(startY, endY), XMax = Math.Max(startX, endX), YMax = Math.Max(startY, endY) };
    IFeatureLayer featureLayer = (IFeatureLayer)axMapControl1.Map.get_Layer(0);
    IFeatureSelection featureSelection = (IFeatureSelection)featureLayer;
    ISpatialFilter spatialFilter = new SpatialFilterClass() { Geometry = envelope, SpatialRel = esriSpatialRelEnum.esriSpatialRelEnvelopeIntersects };
    featureSelection.SelectFeatures(spatialFilter, esriSelectionResultEnum.esriSelectionResultNew, false);
    axMapControl1.Refresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
}

该方法主要实现了选中框选区域内的要素的功能，使用了 IEnvelope、IFeatureLayer、IFeatureSelection 和 ISpatialFilter 接口。

以上就是在 ArcEngine 中通过鼠标控制框选一个区域的基本步骤，您可以根据自己的需要进行调整和扩展。