C#中用Odbc操作DBF

技术2022-05-11 42

using System; using System.Drawing; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; using System.Data.Odbc; using System.Threading; namespace test { /// <summary> /// HR_Form_PersonnelExportDBF 的摘要描述。 /// </summary> public class HR_Form_PersonnelExportDBF : System.Windows.Forms.Form { private System.Windows.Forms.GroupBox groupBox1; private System.Windows.Forms.Button btnOpen; private System.Windows.Forms.Button btnExit; private System.Windows.Forms.Button btnSave; private System.Windows.Forms.FolderBrowserDialog folderBrowserDialog1; System.Windows.Forms.BindingManagerBase myBind; /// <summary> /// 文件名(不包含扩展名) /// </summary> private string _FileName="r_da"; /// <summary> /// 文件路径 /// </summary> private string _FilePath=""; /// <summary> /// 连接字符串 /// </summary> private string _myStrConnection; /// <summary> /// select语句 /// </summary> private string _myStrSelect; OdbcDataAdapter _myAdapter; OdbcConnection _myconn; DataSet myDataSet=new DataSet(); private System.Windows.Forms.DataGrid dataGrid1; private System.Windows.Forms.Button btnCreate; private System.Windows.Forms.Button btnCopy; private System.Windows.Forms.Button btnInsert; private System.Windows.Forms.Button btnDelete; /// <summary> /// 設計工具所需的變數。 /// </summary> private System.ComponentModel.Container components = null; public HR_Form_PersonnelExportDBF() { InitializeComponent(); } /// <summary> /// 清除任何使用中的資源。 /// </summary> protected override void Dispose( bool disposing ) { if( disposing ) { if(components != null) { components.Dispose(); } } base.Dispose( disposing ); } Windows Form 設計工具產生的程式碼 [STAThread] 　　 static void Main() 　　 { Application.Run(new HR_Form_PersonnelExportDBF()); 　　 } private void btnExit_Click(object sender, System.EventArgs e) { this.Close(); } private void btnCreate_Click(object sender, System.EventArgs e) { //数据库连接 this._myStrConnection=@"Driver={Microsoft Visual FoxPro Driver};SourceType=DBF;SourceDB=c:;Exclusive=Yes;"; using(_myconn = new OdbcConnection(this._myStrConnection)) { _myconn.Open(); //生成的dbf文件存放在應用程序所在目錄下,而不是指定的目錄(C:)下,需要手工去複製到指定的目錄 this._FileName="r_da"; using(OdbcCommand comm=new OdbcCommand("create table "+this._FileName+"(da_gh c(7) UNIQUE,da_xm c(8)",_myconn)) { int a=comm.ExecuteNonQuery();//返回值為-1 } } } private void btnOpen_Click(object sender, System.EventArgs e) { //数据库连接 this._myStrConnection=@"Driver={Microsoft Visual FoxPro Driver};SourceType=DBF;SourceDB="+Application.StartupPath+";Exclusive=Yes;"; _myconn = new OdbcConnection(this._myStrConnection); _myconn.Open(); this._myStrSelect="SELECT da_gh,da_xm FROM " + this._FileName; this._myAdapter = new OdbcDataAdapter(this._myStrSelect,_myconn);// OdbcCommandBuilder commandbuilder = new OdbcCommandBuilder(_myAdapter); this.setDataAdapter(this._myAdapter); //填充数据集 _myAdapter.Fill(this.myDataSet,this._FileName); this.dataGrid1.DataSource=this.myDataSet.Tables[this._FileName].DefaultView; this.myBind=this.BindingContext[this.dataGrid1.DataSource]; } private void setDataAdapter(OdbcDataAdapter dataAdapter) { string field; OdbcParameter para; //參數的設定參考了以下文章 //http://msdn.microsoft.com/library/cht/default.asp?url=/library/CHT/cpguide/html/cpconupdatingdatabasewithdataadapterdataset.asp //http://msdn.microsoft.com/library/cht/default.asp?url=/library/CHT/cpguide/html/cpconusingparameterswithdataadapters.asp //insertCommand dataAdapter.InsertCommand=new OdbcCommand("insert into "+this._FileName+"(da_gh,da_xm) values(?,?)",this._myconn); field="da_gh"; para=dataAdapter.InsertCommand.Parameters.Add(new OdbcParameter("@"+field,System.Data.Odbc.OdbcType.NVarChar)); para.SourceColumn=field; field="da_xm"; para=dataAdapter.InsertCommand.Parameters.Add(new OdbcParameter("@"+field,System.Data.Odbc.OdbcType.NVarChar)); para.SourceColumn=field; //updateCommand dataAdapter.UpdateCommand=new OdbcCommand("update "+this._FileName+" set da_xm=? where da_gh=?",this._myconn); field="da_gh"; para=dataAdapter.UpdateCommand.Parameters.Add(new OdbcParameter("@"+field,System.Data.Odbc.OdbcType.NVarChar)); para.SourceColumn=field; para.SourceVersion=DataRowVersion.Original; field="da_xm"; para=dataAdapter.UpdateCommand.Parameters.Add(new OdbcParameter("@"+field,System.Data.Odbc.OdbcType.NVarChar)); para.SourceColumn=field; //deleteCommand dataAdapter.DeleteCommand=new OdbcCommand("delete from "+this._FileName+" where da_gh=?",this._myconn); field="da_gh"; para=dataAdapter.DeleteCommand.Parameters.Add(new OdbcParameter("@"+field,System.Data.Odbc.OdbcType.NVarChar)); para.SourceColumn=field; para.SourceVersion=DataRowVersion.Original; } private void btnInsert_Click(object sender, System.EventArgs e) { if(this.myBind!=null) { int row=this.myDataSet.Tables[this._FileName].Rows.Count; DataRow dr=this.myDataSet.Tables[this._FileName].NewRow(); dr["da_gh"]="b3"+row.ToString().PadLeft(5,'0'); dr["da_xm"]="張三"+row.ToString().PadLeft(4,'0'); this.myDataSet.Tables[this._FileName].Rows.Add(dr); } } private void btnDelete_Click(object sender, System.EventArgs e) { if(this.myBind!=null && this.myBind.Count>0) (this.myBind.Current as DataRowView).Delete(); } private void btnSave_Click(object sender, System.EventArgs e) { if(_myconn.State==ConnectionState.Closed) _myconn.Open(); this._myAdapter.Update(this.myDataSet,this._FileName); } private void btnCopy_Click(object sender, System.EventArgs e) { 選擇存放文件的路徑,並複製表結構到此路徑 } }}

有兩個問題:

1.創建dbf(btnCreate_Click事件)時錯誤:

類型 'System.Data.Odbc.OdbcException' 的未處理例外狀況發生於 system.data.dll

其他資訊: 系統錯誤。

2.在讀取已經存在的dbf到DataSet中后,刪除記錄后,按"Save"按鈕保存數據ok;但當修改了記錄或插入新記錄后,保存數據時出錯誤:

1.創建dbf(btnCreate_Click事件)時錯誤:

類型 'System.Data.Odbc.OdbcException' 的未處理例外狀況發生於 system.data.dll

其他資訊: 系統錯誤。

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