遍历dt

红太狼 2022-06-13 01:41 148阅读 0赞

for (int i = 0; i < dataTable.Rows.Count; i++)
    {
        for (int j = 0; j < dataTable.Columns.Count; j++)
        {
            Console.WriteLine(dataTable.Rows[i][j].ToString()); 
        } 
    }

using System.Data;//添加引用
    
    DataTable dt = new DataTable();
    dt.Columns.Add("product_id",typeof(int));
    dt.Columns.Add("product_name", typeof(string));
    DataRow dr = dt.NewRow();//创建与该表具有相同结构的DATAROW 
    dr["product_id"]=1; 
    dr["product_name"]="产品名称"; 
    dt.Rows.Add(dr);

==========  方法一 
     
      
     
      
      
          
     
      
     
      
      
       DataTable  tblDatas = newDataTable("Datas"); 
     
      
     
      
      
       DataColumn dc = null; 
     
      
     
      
      
          
     
      
     
      
      
       //赋值给dc，是便于对每一个datacolumn的操作 
     
      
     
      
      
       dc =tblDatas.Columns.Add("ID",Type.GetType("System.Int32")); 
     
      
     
      
      
       dc.AutoIncrement= true;//自动增加 
     
      
     
      
      
       dc.AutoIncrementSeed = 1;//起始为1 
     
      
     
      
      
       dc.AutoIncrementStep = 1;//步长为1 
     
      
     
      
      
       dc.AllowDBNull = false;// 
     
      
     
      
      
          
     
      
     
      
      
       dc = tblDatas.Columns.Add("Product",Type.GetType("System.String")); 
     
      
     
      
      
       dc = tblDatas.Columns.Add("Version",Type.GetType("System.String")); 
     
      
     
      
      
       dc = tblDatas.Columns.Add("Description",Type.GetType("System.String")); 
     
      
     
      
      
          
     
      
     
      
      
       DataRow newRow; 
     
      
     
      
      
       newRow = tblDatas.NewRow(); 
     
      
     
      
      
       newRow["Product"] = "大话西游"; 
     
      
     
      
      
       newRow["Version"] = "2.0"; 
     
      
     
      
      
       newRow["Description"] = "我很喜欢"; 
     
      
     
      
      
       tblDatas.Rows.Add(newRow); 
     
      
     
      
      
          
     
      
     
      
      
       newRow = tblDatas.NewRow(); 
     
      
     
      
      
       newRow["Product"] = "梦幻西游"; 
     
      
     
      
      
       newRow["Version"] = "3.0"; 
     
      
     
      
      
       newRow["Description"] = "比大话更幼稚"; 
     
      
     
      
      
       tblDatas.Rows.Add(newRow); 
     
      
     
      
      
         
     
      
     
      
      
         
     
      
     
      
      
       ==========  方法二 
     
      
     
      
      
          
     
      
     
      
      
       DataTable tblDatas = newDataTable("Datas"); 
     
      
     
      
      
       tblDatas.Columns.Add("ID", Type.GetType("System.Int32")); 
     
      
     
      
      
       tblDatas.Columns[0].AutoIncrement = true; 
     
      
     
      
      
       tblDatas.Columns[0].AutoIncrementSeed = 1; 
     
      
     
      
      
       tblDatas.Columns[0].AutoIncrementStep = 1; 
     
      
     
      
      
          
     
      
     
      
      
       tblDatas.Columns.Add("Product",Type.GetType("System.String")); 
     
      
     
      
      
       tblDatas.Columns.Add("Version",Type.GetType("System.String")); 
     
      
     
      
      
       tblDatas.Columns.Add("Description",Type.GetType("System.String")); 
     
      
     
      
      
          
     
      
     
      
      
       tblDatas.Rows.Add(newobject[]{ null,"a","b","c"}); 
     
      
     
      
      
       tblDatas.Rows.Add(newobject[] { null, "a", "b", "c" }); 
     
      
     
      
      
       tblDatas.Rows.Add(new object[] { null, "a", "b", "c" }); 
     
      
     
      
      
       tblDatas.Rows.Add(new object[] { null, "a", "b", "c" }); 
     
      
     
      
      
       tblDatas.Rows.Add(new object[] { null, "a", "b", "c" }); 
     
      
     
      
      
          
     
      
     
      
      
         
     
      
     
      
      
       ==========  方法三 
     
      
     
      
      
         
     
      
     
      
      
       DataTable table = new DataTable (); 
     
      
     
      
      
          
     
      
     
      
      
       //创建table的第一列 
     
      
     
      
      
       DataColumn priceColumn = new DataColumn(); 
     
      
     
      
      
       //该列的数据类型 
     
      
     
      
      
       priceColumn.DataType = System.Type.GetType("System.Decimal"); 
     
      
     
      
      
       //该列得名称 
     
      
     
      
      
       priceColumn.ColumnName = "price"; 
     
      
     
      
      
       //该列得默认值 
     
      
     
      
      
       priceColumn.DefaultValue =50; 
     
      
     
      
      
          
     
      
     
      
      
       // 创建table的第二列 
     
      
     
      
      
       DataColumn taxColumn = new DataColumn(); 
     
      
     
      
      
       taxColumn.DataType = System.Type.GetType("System.Decimal"); 
     
      
     
      
      
       //列名 
     
      
     
      
      
       taxColumn.ColumnName = "tax"; 
     
      
     
      
      
       //设置该列得表达式，用于计算列中的值或创建聚合列 
     
      
     
      
      
       taxColumn.expression_r_r = "price *0.0862"; 
     
      
     
      
      
       // Create third column. 
     
      
     
      
      
       DataColumn totalColumn = new DataColumn(); 
     
      
     
      
      
       totalColumn.DataType = System.Type.GetType("System.Decimal"); 
     
      
     
      
      
       totalColumn.ColumnName = "total"; 
     
      
     
      
      
       //该列的表达式，值是得到的是第一列和第二列值得和 
     
      
     
      
      
       totalColumn.expression_r_r = "price + tax"; 
     
      
     
      
      
          
     
      
     
      
      
       // 将所有的列添加到table上 
     
      
     
      
      
       table.Columns.Add(priceColumn); 
     
      
     
      
      
       table.Columns.Add(taxColumn); 
     
      
     
      
      
       table.Columns.Add(totalColumn); 
     
      
     
      
      
          
     
      
     
      
      
       //创建一行 
     
      
     
      
      
       DataRow row = table.NewRow(); 
     
      
     
      
      
       //将此行添加到table中 
     
      
     
      
      
       table.Rows.Add(row); 
     
      
     
      
      
         
     
      
     
      
      
       //将table放在试图中 
     
      
     
      
      
       DataViewview = new DataView(table); 
     
      
     
      
      
       dg.DataSource = view; 
     
      
     
      
      
          
     
      
     
      
      
       dg.DataBind();