我正在尝试使用printdocument打印数据库中的数据,并将其打印到指定范围内打印数据的位置,但仍有两件事情出错
那些仍然无法正常工作的东西
>在打印时,如果页面几乎被完全使用,它会添加一个空白页面,上面只打印一个标题
>如果页面已满,则下一页再次从该范围的第一项开始(使用多个列表进行修复,因为我无法弄清楚如何使用子列表创建列表)
这是我必须调用printdocument的代码
private void button3_Click(object sender, EventArgs e)//print
{
range();
try
{
if (artikel == true)
{
itemperpage = totalnumber = 0;
printPreviewDialog1.Document = printDocument1;
print = true;
printDocument1.Print();
// this.Close();
}
}
catch (Exception q) { MessageBox.Show("" + q); }
}
这是printdocument的代码
private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
if (artikel == true)
{
Font messageFont = new Font("Arial", 14, System.Drawing.GraphicsUnit.Point);
float currentY = 10;// declare one variable for height measurement
e.Graphics.DrawString(" I N K O O P A R T I K E L E N ", DefaultFont, Brushes.Black, 10, currentY);//this will print one heading/title in every page of the document
currentY += 15;
SqlCommand artprint = new SqlCommand("select * from ART WHERE ART BETWEEN @range AND @range2 ORDER BY ART ASC", Connectie.connMEVO_ART);
if (comboBox1.SelectedIndex <= comboBox2.SelectedIndex)
{
artprint.Parameters.Add("@range", SqlDbType.VarChar).Value = comboBox1.SelectedItem;
artprint.Parameters.Add("@range2", SqlDbType.VarChar).Value = comboBox2.SelectedItem;
}
else if (comboBox2.SelectedIndex <= comboBox1.SelectedIndex)
{
artprint.Parameters.Add("@range", SqlDbType.VarChar).Value = comboBox2.SelectedItem;
artprint.Parameters.Add("@range2", SqlDbType.VarChar).Value = comboBox1.SelectedItem;
}
drART = artprint.ExecuteReader();
try
{
while (totalnumber <= amount - 1 && drART.Read())
{// check the number of items
tostring();//SQL data to string
row = row + Environment.NewLine + "ART LEV LTD MVRD SGR INK CRNI " + " VALUTA KOR ";
row = row + Environment.NewLine + aa + " " + a + " " + b + " " + c + " " + d + " " + m + " " + f + " " + g + " " + h;
row = row + Environment.NewLine + "EH2 EH1 EF OMS ";
row = row + Environment.NewLine + j + " " + k + " " + l + " " + i;
row = row + Environment.NewLine;
e.Graphics.DrawString(row, DefaultFont, Brushes.Black, 50, currentY);//print each item
Debug.WriteLine("" + row);
row = "";
currentY += 80; // set a gap between every item
totalnumber += 1; //increment count by 1
if (itemperpage <= 12)
{
itemperpage += 1; // increment itemperpage by 1
e.HasMorePages = false; // set the HasMorePages property to false , so that no other page will not be added
}
else // if the number of item(per page) is more than 12 then add one page
{
itemperpage = 0; //initiate itemperpage to 0 .
e.HasMorePages = true; //e.HasMorePages raised the PrintPage event once per page .
return;//It will call PrintPage event again
}
}
}
catch (Exception ef)
{
MessageBox.Show("" + ef);
}
artprint.Dispose();
}
}
private void tostring()
{
aa = drART["ART"].ToString();
for (int ss = aa.Length; ss < 8; ss++) { aa = aa + " "; }
a = drART["LEV"].ToString();
for (int ss = a.Length; ss < 10; ss++) { a = a + " "; }
b = drART["LTD"].ToString();
for (int ss = b.Length; ss < 10; ss++) { b = b + " "; }
c = drART["MVRD"].ToString();
for (int ss = c.Length; ss < 10; ss++) { c = c + " "; }
d = drART["SGR"].ToString();
for (int ss = d.Length; ss < 10; ss++) { d = d + " "; }
m = drART["INK"].ToString();
for (int ss = m.Length; ss < 10; ss++) { m = m + " "; }
f = drART["CRNI"].ToString();
for (int ss = f.Length; ss < 10; ss++) { f = f + " "; }
g = drART["VALUTA"].ToString();
for (int ss = g.Length; ss < 3; ss++) { g = g + " "; }
h = drART["KOR"].ToString();
for (int ss = h.Length; ss < 10; ss++) { h = h + " "; }
i = drART["OMS"].ToString();
j = drART["EH2"].ToString();
for (int ss = j.Length; ss < 3; ss++) { j = j + " "; }
k = drART["EH1"].ToString();
for (int ss = k.Length; ss < 3; ss++) { k = k + " "; }
l = drART["EF"].ToString();
for (int ss = l.Length; ss < 10; ss++) { l = l + " "; }
}
最佳答案 您写道,您已经使用了来自网络的资源,我想它会显示出来.我们都这样做但是对它们的质量非常怀疑是非常重要的.当然结合两个来源很可能根本不起作用..
我将首先回顾您的代码中的几个问题,然后向您展示如何在几个页面上从数据库中打印项目的示例.
请帮个忙,谨慎选择变量的名称！是的,这需要更长的时间,但它会支付,相信我. (如果你无法想出任何令人信服的东西,请退后一步！这通常表明你不能很好地理解这个问题.)
让我们来看看：有当前的Y,这是非常好的.还有itemperpage,totalnumber和amount,所有这些都很糟糕！他们要么完全不清楚,要么误导！
让我们设置一些名字更好的：
// layout variables
int itemsPerPage = 40; // how many items fit on one page
int itemHeight = 25; // height of one item in the chosen unit
// print job variables
int totalNumber = -1; // total number of records/items coming from the dbms
int itemsToPrint = 75; // total number of items we want to print
// print progress variables
int itemsPrinted = 0; // number of items printed so far
int pagesPrinted = 0; // number of pages printed
另一个问题是你选择的单位,或者确切地说是缺乏选择单位.默认GraphicsUnit是显示,打印数量为1/100英寸.如果你喜欢我建议用代码写它来记录它.该单元将在整个布局过程中使用,因此它应该在代码中可见！我个人更喜欢毫米.还有其他几个单位..挑选你的但记录下来！
你应该研究的另一件事是String.Format()和string.PadLeft().它们比tostring()方法中的循环好得多！
现在让我们来看看你的具体问题：
一旦我们使用足够的变量和一个可以实际理解的名称而不学习它们,那么在作业结束时具有空页面的那个将会消失.
另一个问题是您设置数据库读取的方式：您需要设置读取器开始打印而不是PrintPage循环.注意：这些实际上是两个循环：一个是while(… reader.Read()),另一个是外部循环：整个PrintPage事件本身就是循环体.
首先让我们看一下range()代码.我把它变成了一个返回最大记录数的函数.我在第一步获取计数.然后我设置DataReader用于实际读取,这将发生在PrintPage事件中：我枚举字段,以便我控制他们的顺序,不要拉入我不需要的东西.
请注意,我使用的是MySql,但这些类几乎相同,只是使用了MySQl前缀.我这里不包含连接代码.当然,我从我自己的数据库中读到..
MySqlConnection DBC = new MySqlConnection("");
MySqlCommand CMD = null;
MySqlDataReader DR = null;
int range ()
{
CMD = new MySqlCommand("select count(0) from test.artists ", DBC);
var count = CMD.ExecuteScalar();
int counter = Convert.ToInt32(count);
CMD = new MySqlCommand("select artist_ID, artist, genres from test.artists ", DBC);
DR = CMD.ExecuteReader();
return (int)counter;
}
现在让我们使用上面的变量来查看print命令：
private void cb_print_Click(object sender, EventArgs e)
{
totalNumber = range();
try
{
if (DBC.State == ConnectionState.Open)
{
pagesPrinted = 0;
printPreviewDlg.Document = printDocument1;
printPreviewDlg.ShowDialog();
}
} catch (Exception q) { MessageBox.Show("" + q); }
DR.Dispose();
}
请注意,Reader是在范围调用中创建的！
最后是PrintPage事件：
private void printDocument1_PrintPage(object sender,
System.Drawing.Printing.PrintPageEventArgs e)
{
// my page unit
e.Graphics.PageUnit = GraphicsUnit.Millimeter;
// starting a new page
int itemsOnPage = 0;
pagesPrinted++;
float currentY = 12;
e.Graphics.DrawString(String.Format(
"HEADER - printing {0} items of {1} - Page {2}",
itemsToPrint, totalNumber, pagesPrinted),
Font, Brushes.Black, 1, currentY);
currentY += 30; // header height
try
{
// page is not full and we want to print more items
while (itemsOnPage < itemsPerPage && itemsPrinted < itemsToPrint - 1
&& DR.Read())
{
string row = String.Format("{0,5:000} Artist: {1,20} ({2}) ",
DR[0], DR[1], DR[2]);
e.Graphics.DrawString(row, DefaultFont, Brushes.Black, 50, currentY);
// Console.WriteLine("" + row);
currentY += itemHeight;
itemsPrinted++;
itemsOnPage++;
// we want to print more items but now the page is full
if ( itemsPrinted < itemsToPrint && itemsOnPage >= itemsPerPage)
{
itemsOnPage = 0;
e.HasMorePages = true;
return;
}
else
{
// this will only be used after all data are printed
e.HasMorePages = false;
}
}
} catch (Exception ef)
{
MessageBox.Show("" + ef);
}
}
