基于ArcGIS10.0和Oracle10g的空间数据管理平台十六（C#开发）-空间数据编辑（上）

今天要介绍的内容比较高级，就是通过可视化的操作进行空间数据的编辑操作。不过这里面涉及到很多难度比较大的高级功能，例如怎样选中一个图元、怎样移动图元、怎样确认图元的位置以及实现编辑的撤销操作等等。下面按照自己实现的步骤详细介绍如下。

1.定义空间数据编辑类的成员变量，具体代码如下：

[csharp]
private IFeatureWorkspace pFW;
private IMapControl3 m_MapControl; //地图控件
private IMap m_pMap;                //地图控件中的地图
private ILayer m_pCurrentLayer;     //地图中的当前操作图层
private IFeature m_pEditFeature;    //当前编辑的要素
private IPoint m_pPoint;            //当前鼠标点击位置
private IDisplayFeedback m_pFeedback; //用于地图显示
private IPointCollection m_pPointCollection; //当前要素的点集
private bool m_bInUse;              //是否处于同一个编辑状态
private bool m_bEditingFtr;         //是否为编辑要素状态
private bool m_bSketching;          //是否为新建要素状态
private bool m_bSelecting;          //是否为选择要素状态
private bool m_bMove;               //是否为移动要素状态

2.初始相关成员变量和数据

[csharp]
private void FrmSpatialDataEdit_Load(object sender, EventArgs e)
{
    // Setup the application
    m_MapControl = (IMapControl3)axMapControl1.GetOcx(); //获取地图控件
    m_pMap = m_MapControl.Map;
    cboTasks.SelectedIndex = 0;
    LoadLayers();       //载入图层
    SetControlStates(); //设置四个命令按钮状态
}

上面代码首先由地图控件来获取它的一个实例对象，然后得到地图控件中的地图对象，接着就调用函数载入图层并设置相应操作按钮的初始化状态。载入图层的代码实现如下：

[csharp]
/// <summary>
/// 载入图层，并在地图空间中加入第一个图层
/// </summary>
private void LoadLayers()
{
    //1.遍历SDE的每一个独立要素集中的要素类
    IWorkspace pW = MapOperation.GetFeatrueWorkspace() as IWorkspace;
    IEnumDataset pED = pW.get_Datasets(esriDatasetType.esriDTFeatureDataset);
    IFeatureDataset pFD = pED.Next() as IFeatureDataset;

    while (pFD != null)
    {
        IFeatureClass pFC;
        IFeatureClassContainer pFCC = pFD as IFeatureClassContainer;
        for (int i = 0; i < pFCC.ClassCount; i++)
        {
            pFC = pFCC.get_Class(i);
            cboLayers.Items.Add(pFC.AliasName);
        }

        pFD = pED.Next() as IFeatureDataset;
    }

    //2.遍历SDE的每一个独立要素类
    pED = pW.get_Datasets(esriDatasetType.esriDTFeatureClass);
    IDataset pD = pED.Next();
    while (pD != null)
    {
        IFeatureClass pFC = pD as IFeatureClass;

        cboLayers.Items.Add(pFC.AliasName);
        pD = pED.Next();
    }

    cboLayers.SelectedIndex = 0;
    AddLayerToMapCtl(cboLayers.SelectedItem.ToString(), true);
}

设置操作按钮的代码如下：

[csharp]
/// <summary>
/// 设置四个命令按键的功能
/// </summary>
private void SetControlStates()
{
    bool bEnabled = InEdit();

    btnStartEditing.Enabled = !bEnabled;
    btnDelete.Enabled = bEnabled;
    btnUndo.Enabled = bEnabled;
    btnStopEditing.Enabled = bEnabled;
    cboTasks.Enabled = bEnabled;

    if (bEnabled)
    {
        lblTask.ForeColor = Color.Black;
    }
    else
    {
        lblTask.ForeColor = Color.Gray;
    }
}

    也有禁止相应按钮功能的函数代码如下：
[csharp]
private void DisableControls()
{
    // Disables all but the layer selection combo
    btnStartEditing.Enabled = false;
    btnDelete.Enabled = false;
    btnUndo.Enabled = false;
    btnStopEditing.Enabled = false;
    lblTask.ForeColor = Color.Gray;
}

3.实现加载图层到图层控件中去，这样就可以在图形控件中进行编辑操作了，具体加载代码如下：

[csharp]
/// <summary>
/// 加入图层到地图空间中
/// </summary>
/// <param name="layerName">图层名称</param>
/// <param name="isVisible">是否显示</param>
private void AddLayerToMapCtl(string layerName, bool isVisible)
{
    if (pFW == null)
    {
        pFW = MapOperation.GetFeatrueWorkspace();
    }
    IFeatureClass pFC;
    try
    {
        pFC = pFW.OpenFeatureClass(layerName);
    }
    catch (Exception)
    {
        return;
    }

    IFeatureLayer pFL = new FeatureLayerClass();
    pFL.FeatureClass = pFC;
    pFL.Name = layerName;
    pFL.Visible = isVisible;

    axMapControl1.Map.AddLayer(pFL);
    axMapControl1.ActiveView.Refresh();
}

4.检查工作空间中是否有数据处于编辑状态，是就返回true。

[csharp]
/// <summary>
/// 检查工作空间中是否有数据处于编辑状态
/// </summary>
/// <returns>是否正在编辑</returns>
private bool InEdit()
{
// Check edit condi

补充：软件开发 , C# ,