How to print the entire string if the length exceeds the page

Question

I have to print one string which may vary in size. What I need is that if this string does not fit on the page the remaining text is printed on another. I know that for this I need to do something using e.HasMorePages but I don’t know how. I did some research but I didn’t find anything relevant. Take a look at part of the code that appears in the event printPage:

string textoFinal = "\n\n\n\n\n\n\n\n\n\n\n" + cabInf + cab + sb.ToString() + soma + stringObs + final + final2;

StringFormat alinhar = new StringFormat(StringFormatFlags.NoClip);

alinhar.Alignment = StringAlignment.Near;

e.Graphics.DrawString(textoFinal, Fonte, Brushes.Black, e.MarginBounds, alinhar);

e.HasMorePages = false;

If I die to true the e.HasMorePages when printing I get a page count loop. I need something to check if the string has exceeded the page limit and, if exceeded, the text that did not fit should be printed on another page.

EDIT
I have this code to print out:

string textoFinal;
string stringCopia;

internal void Imprimir()
{
    Cliente cliente = Clientes[listaClientes.SelectedIndex];

    StringBuilder sb = new StringBuilder();
    foreach (var cli in cliente.Produtos)
    {
        sb.AppendFormat("\n\n{0}.....................Valor: R${1} - Data: {2}", cli.NomeProduto, cli.ValorProduto, cli.DataCompra);
    }
    textoFinal = sb.ToString();
    stringCopia = textoFinal;
    printDocumento.PrintPage += printDocumento_PrintPage;
    Margins margem = new Margins(20, 20, 20, 20);
    printDocumento.DefaultPageSettings.Margins = margem;
    printPrevisao.ShowDialog();
}

At the event printPage appears:

int caracteresNaPagina = 0;
int linhasPorPagina = 0;

var Fonte = new Font("Arial", 9);

e.Graphics.DrawImage(Properties.Resources.logoI, 20, 20);

StringFormat alinhar = new StringFormat(StringFormatFlags.NoClip);

alinhar.Alignment = StringAlignment.Near;

e.Graphics.MeasureString(stringCopia, Fonte, e.MarginBounds.Size, alinhar, out caracteresNaPagina, out linhasPorPagina);

e.Graphics.DrawString(stringCopia, Fonte, Brushes.Black, e.MarginBounds, alinhar);

stringCopia = stringCopia.Substring(caracteresNaPagina);

e.HasMorePages = stringCopia.Length > 0;

if (!e.HasMorePages)
    stringCopia = textoFinal;

This way the rest of the text that did not fit on the page is being written at the beginning of the same page, shuffling the texts instead of moving to another page.

PROBLEM SOLVING
Worked perfectly after removing the line printDocumento.PrintPage += printDocumento_PrintPage;
Why? Because I’m developing this in winforms and already had this method pointing to the event. In this way, the text was written twice on the printing document and scrambled.

Answer 1

What you need to do and measure the text you print:

int caracteresNaPagina = 0;
int linhasPorPagina = 0;

e.Graphics.MeasureString(textoFinal, font,
    e.MarginBounds.Size, StringFormat.GenericTypographic,
    out charactersOnPage, out linesPerPage);

Then print the text and remove from the original text the characters that have already been printed. If there are still characters, set the property HasMorePages to true.

e.Graphics.DrawString(textoFinal, font, Brushes.Black,
    e.MarginBounds, StringFormat.GenericTypographic);

textoFinal= textoFinal.Substring(caracteresNaPagina);

e.HasMorePages = (textoFinal.Length > 0);

In this way the event will continue to be called until no characters exist to print, i.e, when HasMorePages is placed the false.

Note that the text to be printed has to be created in advance (outside the print event).

EDIT:

The control PrintPreviewDialog you’re using to make the preview of the document to be printed calls twice the event PrintPage. The first time he created the preview and the second time if the print button is pressed (and printing is effective).

Due to this and assuming that the text was created outside the event PrintPage, due to the logic to calculate the extra pages, the text will be removed until there are no characters left to print.

textoFinal= textoFinal.Substring(caracteresNaPagina);

e.HasMorePages = (textoFinal.Length > 0);

The problem with this is that the second time you print, when you reuse textoFinal, there are no more characters to print, hence the effective print appears blank. The solution to this will then be.

• Create text to print
• Create a copy of the text to print
• Use the copy created within the event PrintPage

That is to say:

string textoFinal = [crie aqui o seu texto];
string copiaTextoFinal = textoFinal; // Copia do texto. Vao ser removidos caracteres a medida que a impressao ocorre.
PrintPreviewDialog dialog = new PrintPreviewDialog
    {
        Document = new PrintDocument()
    };

dialog.Document.PrintPage += (sender, e) =>
    {
        int charactersOnPage;
        int linesPerPage;

        var fonte = new Font("Arial", 18);

        e.Graphics.MeasureString(copiaTextoFinal, fonte,
                e.MarginBounds.Size, StringFormat.GenericTypographic,
                out charactersOnPage, out linesPerPage);

        e.Graphics.DrawString(copiaTextoFinal, fonte, Brushes.Black, e.MarginBounds, StringFormat.GenericTypographic);

        copiaTextoFinal = copiaTextoFinal.Substring(charactersOnPage);

        // Verifica se ainda existem caracteres para imprimir. Se não, marca a 
        // propriedade como falsa.
        e.HasMorePages = copiaTextoFinal.Length > 0;

        // Se não houverem mais paginas a imprimir, volta a copiar o texto original
        // para a variável de copia. Assim, da próxima vez que o evento for chamado, 
        // tem o texto completo, pronto a imprimir.
        if (!e.HasMorePages)
            copiaTextoFinal = textoFinal;
    };

dialog.ShowDialog();