是否可以仅打印DataGridView中具有值并排除非空值的行中的列？我正在尝试打印那些并且只有那些存储了实际值的那些，但是现在它正在打印所有这些。
以下是实际打印文档的屏幕截图（另存为pdf）：http://imgur.com/HiF9heq
我想删除剩下的空列。
以下是我打印的代码和填充数据表的代码：
private void Printdoc_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
try
{
qbcDataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
// set the left margin of the document to be printed
int leftMargin = e.MarginBounds.Left;
// set the top margin of the document to be printed
int topMargin = e.MarginBounds.Top;
// variable to determine if more pages are to be printed
bool printMore = false;
// temp width
int tmpWidth = 0;
// for the first page to print, set the cell width and header height
if (firstPage)
{
foreach (DataGridViewColumn gridCol in qbcDataGridView.Columns)
{
tmpWidth = (int)(Math.Floor((double)gridCol.Width /
totalWidth * totalWidth *
((double)e.MarginBounds.Width / totalWidth)));
headerHeight = (int)(e.Graphics.MeasureString(gridCol.HeaderText, gridCol.InheritedStyle.Font, tmpWidth).Height) + 2;
// save the width and height of the headers
arrayLeftColumns.Add(leftMargin);
arrayColWidths.Add(tmpWidth);
leftMargin += tmpWidth;
}
}
// loop until all of the grid rows get printed
while (row <= qbcDataGridView.Rows.Count - 1)
{
DataGridViewRow gridRow = qbcDataGridView.Rows[row];
// set the cell height
cellHeight = gridRow.Height + 5;
int count = 0;
// check to see if the current page settings allow more rows to print
if (topMargin + cellHeight >= e.MarginBounds.Height + e.MarginBounds.Top)
{
newPage = true;
firstPage = false;
printMore = true;
break;
}
else
{
if (newPage)
{
// draw the header
e.Graphics.DrawString("QBC Directory",
new Font(qbcDataGridView.Font, FontStyle.Bold),
Brushes.Black, e.MarginBounds.Left,
e.MarginBounds.Top - e.Graphics.MeasureString("QBC Directory",
new Font(qbcDataGridView.Font, FontStyle.Bold),
e.MarginBounds.Width).Height - 13);
// set the data (now) and the current time
String date = DateTime.Now.ToLongDateString() + " " + DateTime.Now.ToShortTimeString();
// draw the date on the print document
e.Graphics.DrawString(date,
new Font(qbcDataGridView.Font, FontStyle.Bold),
Brushes.Black, e.MarginBounds.Left + (e.MarginBounds.Width - e.Graphics.MeasureString(date,
new Font(qbcDataGridView.Font, FontStyle.Bold),
e.MarginBounds.Width).Width),
e.MarginBounds.Top - e.Graphics.MeasureString("QBC Directory", new Font(new Font(qbcDataGridView.Font, FontStyle.Bold),
FontStyle.Bold), e.MarginBounds.Width).Height - 13);
// draw the column headers
topMargin = e.MarginBounds.Top;
foreach (DataGridViewColumn gridCol in qbcDataGridView.Columns)
{
if (!string.IsNullOrEmpty(gridCol.HeaderText))
{
// header color
e.Graphics.FillRectangle(new SolidBrush(Color.LightGray),
new Rectangle((int)arrayLeftColumns[count], topMargin,
(int)arrayColWidths[count], headerHeight));
// header text box
e.Graphics.DrawRectangle(Pens.Black,
new Rectangle((int)arrayLeftColumns[count], topMargin,
(int)arrayColWidths[count], headerHeight));
// header string
e.Graphics.DrawString(gridCol.HeaderText,
gridCol.InheritedStyle.Font, new SolidBrush(gridCol.InheritedStyle.ForeColor),
new RectangleF((int)arrayLeftColumns[count], topMargin, (int)arrayColWidths[count], headerHeight), string_format);
}
else
{
break;
}
count++;
}
newPage = false;
topMargin += headerHeight;
}
count = 0;
// draw the column's contents
foreach (DataGridViewCell gridCell in gridRow.Cells)
{
if (gridCell.Value != null)
{
if (!string.IsNullOrEmpty(gridCell.Value.ToString()))
{
e.Graphics.DrawString(gridCell.Value.ToString(),
gridCell.InheritedStyle.Font, new SolidBrush(gridCell.InheritedStyle.ForeColor),
new RectangleF((int)arrayLeftColumns[count], topMargin, (int)arrayColWidths[count], cellHeight), string_format);
}
else
{
break;
}
}
else
{
break;
}
// draw the borders for the cells
e.Graphics.DrawRectangle(Pens.Black, new Rectangle((int)arrayLeftColumns[count], topMargin, (int)arrayColWidths[count], cellHeight));
count++;
}
}
row++;
topMargin += cellHeight;
// if more lines exist, print another page
if (printMore)
{
e.HasMorePages = true;
}
else
{
e.HasMorePages = false;
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
和填充DataGridView的菜单条项：
private void MenuViewMembers_Click(object sender, EventArgs e)
{
qbcDataGridView.Font = new Font(qbcDataGridView.Font.FontFamily, 10);
qbcDataGridView.Location = new Point(30, 100);
qbcDataGridView.Size = new Size(1500, 500);
dbConn.Open();
DataTable dt = new DataTable();
DbAdapter = new OleDbDataAdapter("select ID, household_head, birthday, phone, email, address, status, spouse, spouse_birthday, spouse_email, anniversary, spouse_status," +
"child1, child1_birthday, child1_email, child2, child2_birthday, child3_birthday, child4, child4_birthday, child4_email, child5, child5_birthday, child5_email," +
"child6, child6_birthday, child6_email, child7, child7_birthday, child7_email from members", dbConn);
DbAdapter.Fill(dt);
qbcDataGridView.DataSource = dt;
qbcDataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
qbcDataGridView.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;
qbcDataGridView.DefaultCellStyle.WrapMode = DataGridViewTriState.True;
dbConn.Close();
Controls.Add(qbcDataGridView);
}
我认为如果只打印非空值，它会正确格式化打印文档（见截图）。
非常感谢任何帮助。
谢谢！
更新 - 我得到了它，所以没有显示空单元格（http://imgur.com/R0ueyft），但我想我的另一个问题是如果单元格为空，如何不显示列标题。我更新了我的代码以反映我所做的更改。
答案 0 :(得分：5)
使用数据填充DataTable后，请浏览列并删除空。
DbAdapter.Fill(dt);
for (int i = dt.Columns.Count - 1; i >= 0; i--)
{
if (dt.AsEnumerable().All(row => row[i].ToString() == ""))
{
dt.Columns.RemoveAt(i);
}
}
qbcDataGridView.DataSource = dt;
答案 1 :(得分：0)
这并不意味着提供一个重复的答案，但这里是Alexander Petrov的答案的增强，为了处理空数据，这可能与从数据库表中读取数据时的空字符串一样，如下：
DbAdapter.Fill(dt);
for (int i = dt.Columns.Count - 1; i >= 0; i--)
{
if (dt.AsEnumerable().All(row => row[i] == null || row => row[i].ToString() == ""))
{
dt.Columns.RemoveAt(i);
}
}
qbcDataGridView.DataSource = dt;
将IEnumerable.All方法用作documented。
答案 2 :(得分：0)
如果您在datagrid中有空行，请擦除它，它将正常工作。 当循环开始并到达数据网格的末尾时，它将返回异常，因为最后一行没有值