在 C# 中打印表单/用户控件

Question

我的程序： 包含一个带有几个文本框和一个按钮的表单。 “默认打印机”在我的计算机上设置为 Adobe PDF。

我的目标：想要在用户单击“打印”按钮时截取表单/用户控件的屏幕截图。然后屏幕截图以 .pdf 格式保存在桌面上。

我的问题：我的代码有以下两个问题：

1. 屏幕截图尺寸：屏幕截图的尺寸太大，打印/转换为.pdf时不适合页面尺寸（默认页面尺寸）。请参考下面的两张图片。我希望整个屏幕截图适合页面。
2. 询问两次转换和保存位置： 当我点击“打印表单”按钮时，程序两次询问我在哪里打印/转换和保存文件。我希望程序只问我一次，在哪里打印和保存文件。

问题1：程序截取的截图在打印时不适合页面。

我希望屏幕截图像​​这样适合 .pdf 的一页：

代码：

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        button1.Text = "Print Form";
        button1.Click += new EventHandler(button1_Click);
        printDocument1.PrintPage += new PrintPageEventHandler(printDocument1_PrintPage);
        this.Controls.Add(button1);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        CaptureScreen();
        printDocument1.Print();
    }

    Bitmap memoryImage;

    private void CaptureScreen()
    {
        Graphics myGraphics = this.CreateGraphics();
        Size s = this.Size;
        memoryImage = new Bitmap(s.Width, s.Height, myGraphics);
        Graphics memoryGraphics = Graphics.FromImage(memoryImage);
        memoryGraphics.CopyFromScreen(this.Location.X, this.Location.Y, 0, 0, s);
    }

    private void printDocument1_PrintPage(System.Object sender, System.Drawing.Printing.PrintPageEventArgs e)
    {
        e.Graphics.DrawImage(memoryImage, 0, 0);
    }
}

提前感谢您的帮助。我是新手，正在学习 c# 语言，非常感谢您的帮助。 :)

Answer 1

好的，看看这个，特别是修改后的printDocument1_PrintPage：

        private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
        {
            // calculate width and height scalings taking page margins into account
            var wScale = e.MarginBounds.Width / (float)_memoryImage.Width;
            var hScale = e.MarginBounds.Height / (float)_memoryImage.Height;

            // choose the smaller of the two scales
            var scale = wScale < hScale ? wScale : hScale;

            // apply scaling to the image
            e.Graphics.ScaleTransform(scale, scale);

            // print to default printer's page
            e.Graphics.DrawImage(_memoryImage, 0, 0);
        }

我将所有事件连线移动到通常应该去的 InitializeComponent 中，但它涉及的代码更多：

using System;
using System.Drawing;
using System.Drawing.Printing;
using System.Windows.Forms;

namespace testScreenCapScale
{
    public partial class Form1 : Form
    {
        public Form1() { InitializeComponent(); }

        private void button1_Click(object sender, EventArgs e)
        {
            CaptureScreen();
            printDocument1.Print();
        }

        private Bitmap _memoryImage;

        private void CaptureScreen()
        {
            // put into using construct because Graphics objects do not 
            //  get automatically disposed when leaving method scope
            using (var myGraphics = CreateGraphics())
            {
                var s = Size;
                _memoryImage = new Bitmap(s.Width, s.Height, myGraphics);
                using (var memoryGraphics = Graphics.FromImage(_memoryImage))
                {
                    memoryGraphics.CopyFromScreen(Location.X, Location.Y, 0, 0, s);
                }
            }
        }

        private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
        {
            // calculate width and height scalings taking page margins into account
            var wScale = e.MarginBounds.Width / (float)_memoryImage.Width;
            var hScale = e.MarginBounds.Height / (float)_memoryImage.Height;

            // choose the smaller of the two scales
            var scale = wScale < hScale ? wScale : hScale;

            // apply scaling to the image
            e.Graphics.ScaleTransform(scale, scale);

            // print to default printer's page
            e.Graphics.DrawImage(_memoryImage, 0, 0);
        }
    }
}

Form1.Designer.cs

namespace testScreenCapScale
{
    partial class Form1
    {
        private System.ComponentModel.IContainer components = null;

        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
                components.Dispose();
            base.Dispose(disposing);
        }

        private void InitializeComponent()
        {
            this.printDocument1 = new System.Drawing.Printing.PrintDocument();
            this.button1 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // printDocument1
            // 
            this.printDocument1.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(this.printDocument1_PrintPage);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(64, 220);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(384, 377);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

        }

        private System.Drawing.Printing.PrintDocument printDocument1;
        private System.Windows.Forms.Button button1;
    }
}