调试易

用索引来控制，根据当前行的索引，然后button控制索引的值增减，来取当前行的内容。

用索引来控制，根据当前行的索引，然后button控制索引的值增减，来取当前行的内容

刚学，还是不明白在哪里加索引？foreach里？

试试下面的方法:
 public partial class Form1 : Form
    {
        DataSet objDS = new DataSet();
        private int m_CurPos = 0;
        private int m_MaxPos = 0;
        private int[] m_TableRowCounts;
        public Form1()
        {
            InitializeComponent();
            m_TableRowCounts = new int[objDS.Tables.Count];
            for (int i = 0; i < objDS.Tables.Count; i++)
            {
                DataTable tbl = objDS.Tables[i];
                m_MaxPos += tbl.Rows.Count;
                m_TableRowCounts[i] = tbl.Rows.Count;
            }
           
        }
        private struct RowIdx
        {
            public int TableIndex;
            public int RowIndex;
        }
        private int CurPosition
        {
            get { return this.m_CurPos; }
            set
            {
                if (value >= 0 && value < m_MaxPos)
                {
                    this.m_CurPos = value;
                    RowIdx idx = this.getRowIdex(value);
                    DataTable tbl=this.objDS.Tables[idx.TableIndex];
                    DataRow objDR = tbl.Rows[idx.RowIndex];
                    this.txt_musicID.Text = objDR[0].ToString();
                    this.txt_musicName.Text = objDR[1].ToString();
                    this.txt_musicAuthor.Text = objDR[2].ToString();
                    this.txt_musicTime.Text = objDR[3].ToString();
                }
            }
        }
        private RowIdx getRowIdex(int position)
        {
            RowIdx idx=new RowIdx();
            int p1 = 0,p2=0;
            for (int i = 0; i < this.m_TableRowCounts.Length ; i++)
            {
                p1+=this.m_TableRowCounts[i];
                if (position < p1)
                {
                    idx.TableIndex = i;
                    idx.RowIndex = position - p2;
                    return idx;
                }
            }
            idx.RowIndex = -1;
            idx.TableIndex = -1;
            return idx;
        }        private void m_BtnNavPrev_Click(object sender, EventArgs e)
        {
            this.CurPosition--;
        }        private void m_BtnNavNext_Click(object sender, EventArgs e)
        {
            this.CurPosition++;
        }
    }

用BindingSource.MoveNext();
BindingSource.MovePrevious();

把这段改为: for (int i = 0; i < this.m_TableRowCounts.Length ; i++)
            {
                p1+=this.m_TableRowCounts[i];
                if (position < p1)
                {
                    idx.TableIndex = i;
                    idx.RowIndex = position - p2;
                    return idx;
                }
p2+=this.m_TableRowCounts[i];//刚漏了这句            }

先谢谢 jointan() 了，他的一行代码使我突然知道做法了；（也有可能是 bestshl(快乐的Coder)的说法用索引，哎偶基础不怎么好）先申明个类的int 变量，用button来++和--;
之后
foreach(DataTable objDT in objDs.Tables)
{

DataRow objDR =objDT.Rows[i];//就是这行，只要直接指定行数就可以得到了；
this.txt_musicID.Text=objDR[0].ToString();
this.txt_musicName.Text=objDR[1].ToString();
this.txt_musicAuthor.Text=objDR[2].ToString();
this.txt_musicTime.Text=objDR[3].ToString();

}
。就这样就全都搞定了。^_^