Ну, взяли другие ответы на код и немного изменили ....
Проблема заключалась в том, что предыдущий код предполагал, что основной монитор является самым верхним и самым левым в новой картинке для создания .... он не работал для меня.
Правка -> понял, что Windows 7 и 10 ведут себя по-разному в отношении начального положения мозаичного изображения. Win 10 начинается слева вверху ... Win 7 всегда начинается с основного монитора.
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using System.Windows.Forms;
using System.IO;
namespace toolbox.Wallpaper
{
public class CustomWally
{
const int SetDeskWallpaper = 20;
const int UpdateIniFile = 0x01;
const int SendWinIniChange = 0x02;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);
Point primaryMonitorPoint = new Point(0, 0);
const string defaultBackgroundFile = @"C:\Users\Public\Pictures\Sample Pictures\DefaultBackground.jpg";
Dictionary<string, Image> images = new Dictionary<string, Image>();
public CustomWally()
{
//figure out where the main monitor is in relation to the virtualScreenBitmap
foreach (Screen scr in Screen.AllScreens)
{
images.Add(scr.DeviceName, null);
screenos.Add(scr.DeviceName);
if (scr.Bounds.Left < primaryMonitorPoint.X)
primaryMonitorPoint.X = scr.Bounds.Left;
if (scr.Bounds.Top < primaryMonitorPoint.Y)
primaryMonitorPoint.Y = scr.Bounds.Top;
}
primaryMonitorPoint.X *= -1;
primaryMonitorPoint.Y *= -1;
//Image for multiple screens
images.Add("all", null);
//set Images in Dictionary in case there are previous Images
if (File.Exists(defaultBackgroundFile))
{
using (var old = new Bitmap(defaultBackgroundFile))
{
foreach (Screen scr in Screen.AllScreens)
{
Rectangle rectangle = new Rectangle(primaryMonitorPoint.X + scr.Bounds.Left, primaryMonitorPoint.Y + scr.Bounds.Top, scr.Bounds.Width, scr.Bounds.Height);
if (old.Width >= (rectangle.X + rectangle.Width) &&
old.Height >= (rectangle.Y + rectangle.Height))
images[scr.DeviceName] = (Bitmap)old.Clone(rectangle, old.PixelFormat);
}
}
}
}
List<string> screenos = new List<string>();
int index = 0;
public void setAlternatingWalls(string file)
{
images[screenos[index]] = Image.FromFile(file);
index++;
if (index == screenos.Count)
index = 0;
CreateBackgroundImage(Method.multiple);
GC.Collect();
}
public void setWallforScreen(Screen screen, string file)
{
images[screen.DeviceName] = Image.FromFile(file);
CreateBackgroundImage(Method.multiple);
GC.Collect();
}
public void setWallforAllScreen(string file)
{
images["all"] = Image.FromFile(file);
CreateBackgroundImage(Method.single);
GC.Collect();
}
private enum Method
{
multiple,
single
}
private void CreateBackgroundImage(Method method)
{
using (var virtualScreenBitmap = new Bitmap((int)System.Windows.Forms.SystemInformation.VirtualScreen.Width, (int)System.Windows.Forms.SystemInformation.VirtualScreen.Height))
{
using (var virtualScreenGraphic = Graphics.FromImage(virtualScreenBitmap))
{
switch (method)
{
// alternated Screen Images
case Method.multiple:
foreach (var screen in System.Windows.Forms.Screen.AllScreens)
{
// gets the image which we want to place in virtualScreenGraphic
var image = (images.ContainsKey(screen.DeviceName)) ? images[screen.DeviceName] : null;
//sets the position and size where the images will go
Rectangle rectangle = new Rectangle(primaryMonitorPoint.X + screen.Bounds.Left, primaryMonitorPoint.Y + screen.Bounds.Top, screen.Bounds.Width, screen.Bounds.Height);
// produce a image for the screen and fill it with the desired image... centered
var monitorBitmap = new Bitmap(rectangle.Width, rectangle.Height);
if (image != null)
DrawImageCentered(Graphics.FromImage(monitorBitmap), image, rectangle);
//draws the picture at the right place in virtualScreenGraphic
virtualScreenGraphic.DrawImage(monitorBitmap, rectangle);
}
break;
//Single screen Image
case Method.single:
// gets the image which we want to place in virtualScreenGraphic
var image2 = images["all"];
//sets the position and size where the images will go
Rectangle rectangle2 = new Rectangle(0, 0, virtualScreenBitmap.Width, virtualScreenBitmap.Height);
// fill with the desired image... centered
if (image2 != null)
DrawImageCentered(virtualScreenGraphic, image2, rectangle2);
//draws the picture at the right place in virtualScreenGraphic
virtualScreenGraphic.DrawImage(virtualScreenBitmap, rectangle2);
break;
}
virtualScreenBitmap.Save(defaultBackgroundFile, ImageFormat.Jpeg);
}
}
RegistryKey key = Registry.CurrentUser.OpenSubKey(@"Control Panel\Desktop", true);
key.SetValue(@"WallpaperStyle", 0.ToString());
key.SetValue(@"TileWallpaper", 1.ToString());
SystemParametersInfo(SetDeskWallpaper, 0, defaultBackgroundFile, UpdateIniFile | SendWinIniChange);
}
private void DrawImageCentered(Graphics g, Image img, Rectangle monitorRect)
{
double ratiodev = (1.0 * monitorRect.Width / monitorRect.Height) - (1.0 * img.Width / img.Height);
if (((1.0 * monitorRect.Width / monitorRect.Height > 1) && ratiodev > -0.25 && ratiodev < 0.25))
{
img = getsnappedIMG(img, monitorRect);
}
float heightRatio = (float)monitorRect.Height / (float)img.Height;
float widthRatio = (float)monitorRect.Width / (float)img.Width;
int height = monitorRect.Height;
int width = monitorRect.Width;
int x = 0;
int y = 0;
if (heightRatio < widthRatio)
{
width = (int)((float)img.Width * heightRatio);
height = (int)((float)img.Height * heightRatio);
x = (int)((float)(monitorRect.Width - width) / 2f);
}
else
{
width = (int)((float)img.Width * widthRatio);
height = (int)((float)img.Height * widthRatio);
y = (int)((float)(monitorRect.Height - height) / 2f);
}
Rectangle rect = new Rectangle(x, y, width, height);
g.DrawImage(img, rect);
}
private Image getsnappedIMG(Image img, Rectangle monitorRect)
{
double ratiodev = (1.0 * monitorRect.Width / monitorRect.Height) - (1.0 * img.Width / img.Height);
int height = img.Height;
int width = img.Width;
Rectangle rect;
if (ratiodev < 0)
{
rect = new Rectangle(0, 0, (int)((1.0 * monitorRect.Width / monitorRect.Height) * height), height);
rect.X = (width - rect.Width) / 2;
}
else
{
rect = new Rectangle(0, 0, width, (int)(1.0 * width / (1.0 * monitorRect.Width / monitorRect.Height)));
rect.Y = (height - rect.Height) / 2;
}
var img2 = (Bitmap)img;
return (Bitmap)img2.Clone(rect, img.PixelFormat);
}
}
}