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public class Utils
{
public static DataTable Merge(params DataTable[] tables)
{
DataTable table3 = new DataTable();
int rowCount = 0;
foreach (DataTable t in tables)
{
foreach (DataColumn c in t.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);
}
rowCount = t.Rows.Count > rowCount ? t.Rows.Count : rowCount;
}
for (int i = 0; i < rowCount; i++)
{
object[] rowItems = new object[table3.Columns.Count];
object[] obj = null;
int index = 0;
foreach (DataTable t in tables)
{
obj = t.Rows.Count > i ? t.Rows[i].ItemArray : new object[t.Columns.Count];
obj.CopyTo(rowItems, index);
index += obj.Length;
}
table3.Rows.Add(rowItems);
}
return table3;
}
}
//测试代码
public static void Main(String[] args)
{
DataTable table1 = new DataTable(); //1行6列
table1.Columns.Add("a1");
table1.Columns.Add("a2");
table1.Columns.Add("a3");
table1.Columns.Add("a4");
table1.Columns.Add("a5");
table1.Columns.Add("a6");
table1.Rows.Add(new object[] { 1,2,3,4,5,6});
DataTable table2 = new DataTable(); //2行2列
table2.Columns.Add("b1");
table2.Columns.Add("b2");
table2.Rows.Add("b1", "b2");
table2.Rows.Add("b1", "b2");
DataTable t = new DataTable(); //3行2列
t.Columns.Add("c1");
t.Columns.Add("c2");
t.Rows.Add("c1", "c2");
t.Rows.Add("c1", "c2");
t.Rows.Add("c1", "c2");
DataTable table3 = Utils.Merge(table1, table2,t);//合并三个表生成新表
//循环输出表中内容,如果为空值输出一个空格
foreach (DataRow r in table3.Rows)
{
for (int i = 0; i < table3.Columns.Count; i++)
{
object obj = r[i];
Console.Write(string.IsNullOrEmpty(r[i].ToString())?" ":r[i].ToString());
}
Console.WriteLine();
}
}
public class Utils
{
public static DataTable Merge(params DataTable[] tables)
{
DataTable table3 = new DataTable();
int rowCount = 0;
foreach (DataTable t in tables)
{
foreach (DataColumn c in t.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);
}
rowCount = t.Rows.Count > rowCount ? t.Rows.Count : rowCount;
}
for (int i = 0; i < rowCount; i++)
{
object[] rowItems = new object[table3.Columns.Count];
object[] obj = null;
int index = 0;
foreach (DataTable t in tables)
{
obj = t.Rows.Count > i ? t.Rows[i].ItemArray : new object[t.Columns.Count];
obj.CopyTo(rowItems, index);
index += obj.Length;
}
table3.Rows.Add(rowItems);
}
return table3;
}
}
public class Utils
{
public static DataTable Merge(DataTable table1, DataTable table2)
{
DataTable table3 = new DataTable();
foreach (DataColumn c in table1.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);
}
foreach (DataColumn c in table2.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);
}
for (int i = 0; i < table1.Rows.Count || i < table2.Rows.Count; i++)
{
object[] o = table1.Rows.Count > i + 1 ? table1.Rows[i].ItemArray : new object[table1.Columns.Count];
object[] o2 = table2.Rows.Count > i + 1 ? table2.Rows[i].ItemArray : new object[table2.Columns.Count];
object[] o3 = new object[o.Length + o2.Length];
o.CopyTo(o3, 0);
o2.CopyTo(o3, o.Length);
table3.Rows.Add(o3);
}
return table3;
}
}
DataTable table1 = new DataTable();
table1.Columns.Add("a1");
table1.Columns.Add("a2");
table1.Columns.Add("a3");
table1.Columns.Add("a4");
table1.Columns.Add("a5");
table1.Columns.Add("a6");
table1.Rows.Add(new object[] { 1,2,3,4,5,6});
DataTable table2 = new DataTable();
table2.Columns.Add("b1");
table2.Columns.Add("b2");
table2.Rows.Add(new object[] { "b1", "b2" });
DataTable table3 = new DataTable();
foreach (DataColumn c in table1.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);//先添加的table1的Columns
}
foreach (DataColumn c in table2.Columns)
{
table3.Columns.Add(c.ColumnName, c.DataType);//后添加的table2的Columns
}
for (int i = 0; i < table1.Rows.Count || i < table2.Rows.Count; i++)
{
//取值的时候先取table1,再取table2
object[] o = table1.Rows[i] == null ? new object[table1.Columns.Count] : table1.Rows[i].ItemArray;
object[] o2 = table2.Rows[i] == null ? new object[table2.Columns.Count] : table2.Rows[i].ItemArray;
object[] o3 = new object[o.Length + o2.Length];
o.CopyTo(o3,0);//copy的时候先copy table1
o2.CopyTo(o3, o.Length);//再copy table2(与前面的列对应)
table3.Rows.Add(o3);
}