如何将两个 bmp 打印到两个不同的页面中？

Question

我正在尝试的方式是生成两个重叠的图像。

我可以制作两个不同的按钮来打印两个单独的 bmp，但我需要将两个 bmp 打印在同一页上，因为用户可以选择 PDF 打印机并生成一个两页文件。

void Imprimir()
{
    PrintDocument pd = new PrintDocument();
    pd.DocumentName = "Relatório SisIndice";
    pd.PrintPage += new PrintPageEventHandler(doc_PrintPage);
    pd.DefaultPageSettings.Landscape = true;
    PrintDialog printDialog1 = new PrintDialog();
    printDialog1.Document = pd;
    DialogResult result = printDialog1.ShowDialog();
    if (result == DialogResult.OK)
    {    
        pd.Print();
    }
}

private void doc_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
    Bitmap bmp = new Bitmap(pnlPrint.Width, pnlPrint.Height, pnlPrint.CreateGraphics());
    pnlPrint.DrawToBitmap(bmp, new Rectangle(0, 0, pnlPrint.Width, pnlPrint.Height));
    RectangleF bounds = e.PageSettings.PrintableArea;
    float factor = ((float)bmp.Height / (float)bmp.Width);
    e.Graphics.DrawImage(bmp, bounds.Left, bounds.Top, 1118, 855);
    e.HasMorePages = true;
    Bitmap bmp1 = new Bitmap(dgvDetGraf.Width, dgvDetGraf.Height, dgvDetGraf.CreateGraphics());
    dgvDetGraf.DrawToBitmap(bmp1, new Rectangle(0, 1800, dgvDetGraf.Width, dgvDetGraf.Height));
    RectangleF bounds1 = e.PageSettings.PrintableArea;
    e.Graphics.DrawImage(bmp1, bounds1.Left, bounds1.Top, 894, 684);
    e.HasMorePages = false;

}

Answer 1

您已经接近了，但您错过了针对单个页面触发的 PrintPage 事件。在那种情况下，您必须在其Graphics 对象上完成所有绘画/绘图。当没有更多页面时，您将 HasMorePages 设置为 false。

因此，您不必一次绘制所有这些位图，而是必须跟踪您是在第 1 页还是在第 2 页，并在此基础上在该页面上绘制您想要的位图。

我选择了可​​能可行的最简单的解决方案，它涉及一个 page 变量来跟踪我们所在的页面。

int page = 0; 

void Imprimir()
{
    // snip irrelevant stuf
    if (result == DialogResult.OK)
    {   
        // reset our state to page 1
        page = 1;
        pd.Print();
    }
}

private void doc_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
    // this gets called twice, the page variable
    // keeps track of what to do (it keeps the State)
    switch(page)
    {
        // do this for page 1
        case 1:
            Bitmap bmp = new Bitmap(pnlPrint.Width, pnlPrint.Height, pnlPrint.CreateGraphics());
            pnlPrint.DrawToBitmap(bmp, new Rectangle(0, 0, pnlPrint.Width, pnlPrint.Height));
            RectangleF bounds = e.PageSettings.PrintableArea;
            float factor = ((float)bmp.Height / (float)bmp.Width);
            e.Graphics.DrawImage(bmp, bounds.Left, bounds.Top, 1118, 855);
            e.HasMorePages = true;
            break;
        // do this for page 2
        case 2:
            Bitmap bmp1 = new Bitmap(dgvDetGraf.Width, dgvDetGraf.Height, dgvDetGraf.CreateGraphics());
            dgvDetGraf.DrawToBitmap(bmp1, new Rectangle(0, 1800, dgvDetGraf.Width, dgvDetGraf.Height));
            RectangleF bounds1 = e.PageSettings.PrintableArea;
            e.Graphics.DrawImage(bmp1, bounds1.Left, bounds1.Top, 894, 684);
            e.HasMorePages = false;
            break;
    }
    // don't forget to go the next state ... 
    page++; // increase page counter
}