基于ArcGIS10.0和Oracle10g的空间数据管理平台十三（C#开发）-空间数据导出

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前面有几篇文章专门介绍了空间数据的导入，导入的目的是为了统一管理。今天介绍空间数据导出，导出的格式支持和导入的格式一样，导出的目的是为了方便数据的迁移。其实导入和导出用到的技术基本上都是相同的，不过为了介绍的完整性还是单独拿出来，因为这一部分的功能也是很重要而且是必不可少的！

1.首先定义一个用于操作SDE数据库的工作空间并且在构造函数中初始化（调用工具类里面提供的静态方法初始化）：

private IFeatureWorkspace pWorkspaceSDE;//定义SDE工作空间 public FrmDataExport() { InitializeComponent(); if (pWorkspaceSDE == null) { pWorkspaceSDE = MapOperation.GetFeatrueWorkspace(); } }

2.列出所有数据表：供用户选择需要导出的数据，每一个表是一个可选项，这样用户可以一次导出多个需要的数据表。

/// <summary> /// 列出所有的表信息 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void FrmDataExport_Load(object sender, EventArgs e) { SqlHelper sh = new SqlHelper(); string sql = string.Empty; sql = "select table_name,table_mapname,type from layer l,element e where " + "e.id=l.pid and e.category='矢量数据'"; OracleDataReader odr = sh.ReturnDataReader(sql); object[] obj = new object[4]; while (odr.Read()) { obj[0] = false; obj[1] = odr[0].ToString(); obj[2] = odr[2].ToString(); obj[3] = odr[1].ToString(); dataGridViewX1.Rows.Add(obj); } comboBoxEx1.SelectedIndex = 0; }

3.根据选择的导出数据格式打开相应的文件

/// <summary> /// 根据选择的导出数据格式打开相应的文件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void selectPathBtn_Click(object sender, EventArgs e) { //根据导出数据格式打开相应的文件 switch (comboBoxEx1.SelectedIndex) { case 0: { FolderBrowserDialog folder = new FolderBrowserDialog(); if (folder.ShowDialog() == DialogResult.OK) { if (folder.SelectedPath != "") { selectPathTxt.Text = folder.SelectedPath; } } } break; case 1: { OpenFileDialog ofd = new OpenFileDialog(); ofd.Filter = "MDB文件(.mdb) | *.mdb"; ofd.CheckFileExists = false; if (ofd.ShowDialog() == DialogResult.OK) { if (ofd.FileName != "") { selectPathTxt.Text = ofd.FileName; } } } break; default: break; } }

4.执行具体的导出功能：一起准备工作都做好了就开始执行具体的导出功能了，根据不同的格式执行相应导出格式的功能。

/// <summary> /// 执行具体的导出功能 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void exportBtn_Click(object sender, EventArgs e) { if (selectPathTxt.Text == "") { MessageBox.Show("请选择导出路劲"); return; } IWorkspaceFactory pWF = null; switch (comboBoxEx1.SelectedIndex) { case 0: { if (!File.Exists(selectPathTxt.Text)) { } //创建一个输出shp文件的工作空间 pWF = new ShapefileWorkspaceFactoryClass(); IFeatureWorkspace pFW = pWF.OpenFromFile(selectPathTxt.Text, 0) as IFeatureWorkspace; IWorkspace pW = pFW as IWorkspace; for (int i = 0; i < dataGridViewX1.Rows.Count; ++i) { if (bool.Parse(dataGridViewX1.Rows[i].Cells[0].Value.ToString())) { if (dataGridViewX1.Rows[i].Cells[2].Value.ToString() != "PA") { string str = dataGridViewX1.Rows[i].Cells[1].Value.ToString(); MapOperation.ConvertFeatureClass(pWorkspaceSDE as IWorkspace, pW, str, str, 4326); } else { MessageBox.Show("属性表不能够导出为Shape文件"); } } } MessageBox.Show("导出数据完成!"); } break; case 1: { // Instantiate an Access workspace factory and create a new personal geodatabase. pWF = new AccessWorkspaceFactoryClass(); IWorkspaceName pWN = pWF.Create(Path.GetDirectoryName(selectPathTxt.Text), Path.GetFileName(selectPathTxt.Text),null, 0); // Cast the workspace name object to the IName interface and open the workspace. IName pN = (IName)pWN; IWorkspace pW = (IWorkspace)pN.Open(); for (int i = 0; i < dataGridViewX1.Rows.Count; ++i) { if (bool.Parse(dataGridViewX1.Rows[i].Cells[0].Value.ToString())) { string str = dataGridViewX1.Rows[i].Cells[1].Value.ToString(); if (dataGridViewX1.Rows[i].Cells[2].Value.ToString() != "PA") { MapOperation.ConvertFeatureClass(pWorkspaceSDE as IWorkspace, pW, str, str, 4326); } else { ITable pSourceT = pWorkspaceSDE.OpenTable(str); IFeatureWorkspace pFW = pW as IFeatureWorkspace; ITable pTargetT = pFW.CreateTable(str, pSourceT.Fields, null, null, ""); FusedIndexTable(ref pSourceT, ref pTargetT); } } } MessageBox.Show("导出数据完成!"); } break; default: break; } }

5.如果导出的数据表或文件已经存在就以追加的方式导出数据

/// <summary> /// 如果目的数据库中已经有表，则将新的记录追加进去 /// </summary> /// <param name="FromTable">导出表</param> /// <param name="ToTable">导入表</param> private void FusedIndexTable(ref ITable FromTable, ref ITable ToTable) { if (FromTable == null || ToTable == null) { return; } IRow pFromRow; ICursor pToCursor, pFromCursor; IRowBuffer pToRowBuffer; int pIndex; pToRowBuffer = ToTable.CreateRowBuffer(); pToCursor = ToTable.Insert(true); pFromCursor = FromTable.Search(null, false); pFromRow = pFromCursor.NextRow(); while (pFromRow != null) { for (int i = 0; i < pFromRow.Fields.FieldCount; i++) { pIndex = pToRowBuffer.Fields.FindField(pFromRow.Fields.get_Field(i).Name.Trim()); if (pFromRow.Fields.get_Field(i).Editable && pIndex > -1) { pToRowBuffer.set_Value(pIndex, pFromRow.get_Value(i)); } } pToCursor.InsertRow(pToRowBuffer); pFromRow = pFromCursor.NextRow(); } System.Runtime.InteropServices.Marshal.ReleaseComObject(pToCursor); pFromRow = null; pFromCursor = null; pToRowBuffer = null; } }

6.总结：这里用到的大部分技术在前面都介绍过了，这里不过是不同的业务逻辑而已，其实很多的时候高深的技术并不会用到很多，主要是处理好各个功能的业务逻辑，至于用什么样的技术实现都是可以的！