...
yourDGV.DataSource = dt;
...

yourDGV.Columns[0].HeaderText = "";

...


for (int i = 0; i <= yourDGV.ColumnCount - 1; i++)
{
    //可以像這樣一次調整多個column
    yourDGV.Columns[i].ReadOnly = true;
    yourDGV.Columns[i].DefaultCellStyle
 
.Alignment = DataGridViewContentAlignment.MiddleLeft;
}

int colCount = yourDGV.ColumnCount;

for (int i = 0; i < colCount; i++)
{
    if (i == (colCount - 1))
    {
        yourDGV.Columns[i].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;
    }
    else
    {
        yourDGV.Columns[i].AutoSizeMode
 
 = DataGridViewAutoSizeColumnMode.DisplayedCells; // YS:改成可調整欄位大小(下一行)
    }
}


// [ 增加 checkbox]
DataGridViewColumn colCheck = new DataGridViewCheckBoxColumn();
colCheck.Width = 45;
yourDGV.Columns.RemoveAt(0);//change first column to checkbox
yourDGV.Columns.Insert(0, colCheck);
yourDGV.Columns[0].HeaderText
 
 = "選取";

//全部選取
CheckboxAllSelected(yourDGV, true);


//全部取消
CheckboxAllSelected(yourDGV, false);




// Checkbox 全選/取消 Methods
private void CheckboxAllSelected(DataGridView dgv_tg, Boolean checkd_status)
{
    for(int i = 0; i < dgv_tg.RowCount; i++)
    {
        dgv_tg.Rows[i].Cells[0].Value = checkd_status;
    }
}