使用空格/缩进的C#打印

Question

嗨，我正在尝试使用C#应用程序的收据打印机打印一张账单/收据。

预期输出是这样的：

ITEM NAME                 QTY     PRICE
Banana Large Yellow        1       2.00
Brie Cheese 6 pack round   3      30.00
Indian Mango Box          10     246.00

我一直在使用string.format函数，但是输出常常不对齐，并且GET的间距取决于项目名称长度等。

ITEM NAME                 QTY     PRICE
Banana Large Yellow        1       2.00
Brie Cheese 6 pack round     3      30.00
Indian Mango Box        10    246.00

怎样才能解决这个问题？

我使用的代码是

test_string = "-------------------------------\r\n";
        test_string += "First Name | Last Name  |   Age\r\n";
        test_string += String.Format("{0,-10} | {1,-10} | {2,5}", "Bill", "Gates", 51) + "\r\n";
        test_string += String.Format("{0,-10} | {1,-10} | {2,5}", "Edna", "Parker", 114) + "\r\n";
        test_string += String.Format("{0,-10} | {1,-10} | {2,5}", "Johnny", "Depp", 44) + "\r\n";

StringFormat format = new StringFormat();
        format.Alignment = StringAlignment.Center;      // Horizontal Alignment 

        StringFormat right = new StringFormat();
        right.Alignment = StringAlignment.Far; 

        // Measure string.
        SizeF stringSize = new SizeF();
        pd.PrintPage += delegate(object sender, PrintPageEventArgs e)
            {
                string measureString = data;
                Font stringFont = new Font("Arial", 16);


                stringSize = e.Graphics.MeasureString(measureString, stringFont);

                RectangleF rect = new RectangleF(0, height_value, pd.DefaultPageSettings.PrintableArea.Width, pd.DefaultPageSettings.PrintableArea.Height);                   
                if (weight == "bold")
                {
                    if (alignment == "center")
                    {
                        e.Graphics.DrawString(data, new Font(font, 11, System.Drawing.FontStyle.Bold), new SolidBrush(System.Drawing.Color.Black), rect, format);
                    }
                    else
                    {
                        e.Graphics.DrawString(data, new Font(font, 11, System.Drawing.FontStyle.Bold), new SolidBrush(System.Drawing.Color.Black), rect);
                    }
                }
                else
                {
                    if (alignment == "center")
                    {
                        e.Graphics.DrawString(data, new Font(font, 11), new SolidBrush(System.Drawing.Color.Black), rect, format);
                    }
                    else if (alignment == "right")
                    {
                        e.Graphics.DrawString(data, new Font(font, 11), new SolidBrush(System.Drawing.Color.Black), rect, right);                           
                    }
                    else
                    {
                        e.Graphics.DrawString(data, new Font(font, 11), new SolidBrush(System.Drawing.Color.Black), rect);
                    }

                }
                height_value = Convert.ToInt32(stringSize.Height) + height_value;
            };

public string Test()
    {
        string[] names = { "Banana Large Yellow", "Brie Cheese", "Indian Mango Box" };
        int[] quantities = { 1, 3, 10 };
        decimal[] prices = { 2.00m, 30.00m, 246.00m };

        string format = "{0,-25} {1,-10} {2,5}" + Environment.NewLine;
        var stringBuilder = new StringBuilder().AppendFormat(format, "Item Name", "QTY", "Price");
        for (int i = 0; i < names.Length; i++)
        {
            stringBuilder.AppendFormat(format, names[i], quantities[i], prices[i]);
        }

     PrintFormat(stringBuilder.ToString(), "Arial", "normal", "left", 20);
    }

Answer 1

为了以表格式结构打印数据，可以使用string.format使用带宽度和对齐方式的格式项。

一起来看看它的工作原理：

// in comments underscores mean spaces
Console.WriteLine("Res:{0,6}.", 12345); //   Res:_12345.
Console.WriteLine("Res:{0,-6}.", 12345); //  Res:12345_.

但如果生成的字符串长度大于指定的宽度怎么办？然后打印结果，就好像根本没有对齐和宽度一样。

Console.WriteLine("Res:{0,-6}", 123456789); //  Res:123456789.
Console.WriteLine("Res:{0,6}.", 123456789); //  Res:123456789.

您应该更好地使用StringBuilder.AppendFormat。它与格式项一起工作，就像string.format或console.writeline一样。