Arc Engine二次开发——弹窗进行属性查询

在Arcmap中使用Sapefile格式的矢量数据时，经常会用到其属性查询的功能，弹出窗体然后用户鼠标点击或手动输入查询条件，进而查询到感兴趣的要素。在AE二次开发中也经常需要这个功能，于是在此记录整个开发过程。

首先当然是需要构建一个Visual C# Windows窗体应用程序，然后添加axMapControl等控件，这些过程不再赘述。

然后新建一个名为FormQueryAttr.cs的窗体，用于属性查询时弹出，其界面设置为如下：

其中要素为：一个ComboBox（cboLayer）；两个ListBox（listBoxField和listBoxValue）；一个GroupBox；一个TextBox（textBoxSql）

21个Button，表达式所需的19个button的名称如下：

btnequal、btnunequal、btnis、btnlike、btnmore、btnless、btnmoe、btnloe、btnor、btnnull、btnnot、btnand、btnin、btnunderline、btnpercent、btncharacter、btnbetween、btnspace、btnempty

点击查看代码，添加以下变量并在构造函数中添加以下语句：

        //地图数据 
        private AxMapControl mMapControl;
        //选中的图层 
        private IFeatureLayer mFeatureLayer;
        //根据所选择的图层查询得到的特征类
        private IFeatureClass pFeatureClass = null;

        public FormQueryAttr(AxMapControl mapControl)
        {
            InitializeComponent();
            this.mMapControl = mapControl;
        }

接着回到程序主界面，添加属性查询的Button按钮，在其点击响应函数中添加如下代码：

        //属性查询
        private void barButtonItem13_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            FormQueryAttr formqueryattr = new FormQueryAttr(this.axMapControl1);
            formqueryattr.Show();
        }

至此，程序运行且用户点击“属性查询”按钮时，会初始化FormQueryAttr.cs窗体，将整个axMapControl作为参数传入，并显示窗体。

然后再回到FormQueryAttr.cs窗体的代码中，做以下更改：

在其Load函数中为cboLayer添加所有图层名称，代码如下：

        private void FormQueryAttr_Load(object sender, EventArgs e)
        {
            //MapControl中没有图层时返回 
            if (this.mMapControl.LayerCount <= 0)
                return;
            //获取MapControl中的全部图层名称，并加入ComboBox 
            ILayer pLayer;
            //图层名称 
            string strLayerName;
            for (int i = 0; i < this.mMapControl.LayerCount; i++)
            {
                pLayer = this.mMapControl.get_Layer(i);
                strLayerName = pLayer.Name;
                //图层名称加入cboLayer 
                this.cboLayer.Items.Add(strLayerName);
            }
            //默认显示第一个选项 
            this.cboLayer.SelectedIndex = 0;
        }

为cboLayer添加SelectedIndexChanged响应事件，其中代码如下：

        private void cboLayer_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.listBoxField.Items.Clear();
            //获取cboLayer中选中的图层 
            mFeatureLayer = mMapControl.get_Layer(cboLayer.SelectedIndex) as IFeatureLayer;
            pFeatureClass = mFeatureLayer.FeatureClass;
            string strFldName;
            for (int i = 0; i < pFeatureClass.Fields.FieldCount; i++)
            {
                strFldName = pFeatureClass.Fields.get_Field(i).Name;
                this.listBoxField.Items.Add(strFldName);
            }
            this.listBoxField.SelectedIndex = 0;
            this.label8.Text = mFeatureLayer.Name;
        }

为listBoxField添加SelectedIndexChanged和DoubleClick响应事件，其中代码如下：

        private void listBoxField_SelectedIndexChanged(object sender, EventArgs e)
        {
            string sFieldName = listBoxField.Text;
            listBoxValue.Items.Clear();
            int iFieldIndex = 0;
            IField pField = null;
            IFeatureCursor pFeatCursor = pFeatureClass.Search(null, true);
            IFeature pFeat = pFeatCursor.NextFeature();
            iFieldIndex = pFeatureClass.FindField(sFieldName);
            pField = pFeatureClass.Fields.get_Field(iFieldIndex);
            while (pFeat != null)
            {
                listBoxValue.Items.Add(pFeat.get_Value(iFieldIndex));
                pFeat = pFeatCursor.NextFeature();
            }

        }
        private void listBoxField_DoubleClick(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = listBoxField.SelectedItem.ToString() + " ";
        }

为listBoxValue添加DoubleClick响应事件，其中代码如下：

        private void listBoxValue_DoubleClick(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = listBoxValue.SelectedItem.ToString() + " ";
        }

然后对“表达式”中的按钮添加对应的点击响应函数，具体代码如下：

        private void btnequal_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "= ";
        }

        private void btnis_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "is ";
        }

        private void btncharacter_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "'' ";
        }

        private void btnempty_Click(object sender, EventArgs e)
        {
            this.textBoxSql.Text = "";
        }

        private void btnunequal_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "!= ";
        }

        private void btnlike_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "like ";
        }

        private void btnmore_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "> ";
        }

        private void btnmoe_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = ">= ";
        }

        private void btnloe_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "<= ";
        }

        private void btnor_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " or ";
        }

        private void btnnull_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "Null ";
        }

        private void btnless_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "< ";
        }

        private void btnnot_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " Not ";
        }

        private void btnand_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " And ";
        }

        private void btnin_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " In ";
        }

        private void btnunderline_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "_";
        }

        private void btnpercent_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = "% ";
        }

        private void btnbetween_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " Between ";
        }

        private void btnspace_Click(object sender, EventArgs e)
        {
            textBoxSql.SelectedText = " ";
        }

最后对按钮“查找”和“取消”添加点击响应函数，代码如下：

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                mMapControl.Map.ClearSelection(); //清除上次查询结果
                IActiveView pActiveView = mMapControl.Map as IActiveView;
                //pQueryFilter的实例化 
                IQueryFilter pQueryFilter = new QueryFilterClass();
                //设置查询过滤条件 
                pQueryFilter.WhereClause = textBoxSql.Text;
                //search的参数第一个为过滤条件，第二个为是否重复执行
                IFeatureCursor pFeatureCursor = mFeatureLayer.Search(pQueryFilter, false);
                //获取查询到的要素 
                IFeature pFeature = pFeatureCursor.NextFeature();
                //判断是否获取到要素 
                while (pFeature != null)
                {
                    mMapControl.Map.SelectFeature(mFeatureLayer, pFeature); //选择要素 
                    pFeature = pFeatureCursor.NextFeature();
                }
                pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
                pActiveView.Refresh();//刷新图层
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Hide();
        }

到此为止，所有属性查询的工作已经完成，使用效果如下图所示：

如果需要清除所选要素，则添加按钮，并在其点击响应函数中添加如下代码即可：

        //清空查询
        private void barButtonItem14_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            axMapControl1.Map.ClearSelection();
            axMapControl1.Refresh();
        }