c# - 知道DPI和Rect

原文 标签 c# bitmap screenshot rect dpi-aware

我有一个小问题,似乎找不到答案。我有一个应用程序,它可以得到特定的进程并得到它的窗口大小。唯一的问题是它占用了实际屏幕大小的一个百分比(用户可以看到)。
我想做一个应用程序的屏幕截图,但如果我使用窗口的矩形,我会得到一个比它小的屏幕,因为分辨率是125%。这意味着我最初输出的分辨率(1280 * 800)比我的屏幕分辨率(1600 * 1000)小,你可以理解,这个小故障使我的程序不可靠。我的问题是如何解决这个问题?
我已经创建了一个清单,并将DPIAware设置为true。此外,我在调试中禁用了visual studio宿主。但没用。我仍然得到同样的值和同样的问题。以下是我的实际屏幕截图代码片段:

RECT Rect = new RECT();
System.Diagnostics.Process[] p = System.Diagnostics.Process.GetProcessesByName("Process");
ShowWindow(p[0].MainWindowHandle, 9);
SetForegroundWindow(p[0].MainWindowHandle);

if (GetWindowRect(p[0].MainWindowHandle, ref Rect))
{
    var bmp = new Bitmap(Rect.Width, Rect.Height);
    var graphics = Graphics.FromImage(bmp);
    graphics.CopyFromScreen(Rect.Left, Rect.Top, 0, 0, new Size(Rect.Width, Rect.Height), CopyPixelOperation.SourceCopy);
    bmp.Save(@"C:\Screenshots\temp1.png");
}

这给了我一张1280 * 800的截图,不足以覆盖整个过程,也就是1600 * 1000。因为屏幕坐标不对,所以一切都关闭了。如果我把每件事都乘以1,25就可以了,但这不是一个解决方案,因为我不知道其他电脑的dpi设置是什么。
编辑3:
我会把完整的代码加上rect。
RECT Rect = new RECT();
System.Diagnostics.Process[] p = System.Diagnostics.Process.GetProcessesByName("LoLPatcherUx");
ShowWindow(p[0].MainWindowHandle, 9);
SetForegroundWindow(p[0].MainWindowHandle);

if (GetWindowRect(p[0].MainWindowHandle, ref Rect))
{
    int processH = Rect.Bottom - Rect.Top;
    int processW = Rect.Right - Rect.Left;

    float processWidth;
    float processHeight;                            

    SizeF dpi = GetCurrentDpi();
    // Calc the scale.
    SizeF scale = new SizeF()
    {
        Width = dpi.Width / 96f,
        Height = dpi.Height / 96f                                  
    };

    // Scale the rectangle.
    processWidth = Rect.Width * scale.Width;
    processHeight = Rect.Height * scale.Height;

    var bmp = new Bitmap(lolPatcherBreedte, lolPatcherHoogte);
    Graphics graphics = Graphics.FromImage(bmp);
    graphics.CopyFromScreen(Rect.Left, Rect.Top, 0, 0, new Size(processW, processH));

    bmp.Save(@"C:\Screenshots\temp1.png");
}

public struct RECT
{
    private int _Left;
    private int _Top;
    private int _Right;
    private int _Bottom;

    public RECT(RECT Rectangle)
        : this(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom) { }

    public RECT(int Left, int Top, int Right, int Bottom)
    {
        _Left = Left;
        _Top = Top;
        _Right = Right;
        _Bottom = Bottom;
    }

    public int X
    {
        get { return _Left; }
        set { _Left = value; }
    }

    public int Y
    {
        get { return _Top; }
        set { _Top = value; }
    }

    public int Left
    {
        get { return _Left; }
        set { _Left = value; }
    }

    public int Top
    {
        get { return _Top; }
        set { _Top = value; }
    }

    public int Right
    {
        get { return _Right; }
        set { _Right = value; }
    }

    public int Bottom
    {
        get { return _Bottom; }
        set { _Bottom = value; }
    }

    public int Height
    {
        get { return _Bottom - _Top; }
        set { _Bottom = value + _Top; }
    }

    public int Width
    {
        get { return _Right - _Left; }
        set { _Right = value + _Left; }
    }

    public Point Location
    {
        get { return new Point(Left, Top); }
        set
        {
            _Left = value.X;
            _Top = value.Y;
        }
    }

    public Size Size
    {
        get { return new Size(Width, Height); }
        set
        {
            _Right = value.Width + _Left;
            _Bottom = value.Height + _Top;
        }
    }

    public static implicit operator Rectangle(RECT Rectangle)
    {
        return new Rectangle(Rectangle.Left, Rectangle.Top, Rectangle.Width, Rectangle.Height);
    }

    public static implicit operator RECT(Rectangle Rectangle)
    {
        return new RECT(Rectangle.Left, Rectangle.Top, Rectangle.Right, Rectangle.Bottom);
    }

    public static bool operator ==(RECT Rectangle1, RECT Rectangle2)
    {
        return Rectangle1.Equals(Rectangle2);
    }

    public static bool operator !=(RECT Rectangle1, RECT Rectangle2)
    {
        return !Rectangle1.Equals(Rectangle2);
    }

    public override string ToString()
    {
        return "{Left: " + _Left + "; " + "Top: " + _Top + "; Right: " + _Right + "; Bottom: " + _Bottom + "}";
    }

    public override int GetHashCode()
    {
        return ToString().GetHashCode();
    }

    public bool Equals(RECT Rectangle)
    {
        return Rectangle.Left == _Left && Rectangle.Top == _Top && Rectangle.Right == _Right && Rectangle.Bottom == _Bottom;
    }

    public override bool Equals(object Object)
    {
        if (Object is RECT)
        {
            return Equals((RECT)Object);
        }
        else if (Object is Rectangle)
        {
            return Equals(new RECT((Rectangle)Object));
        }

        return false;
    }
}

最佳答案

您可以通过
Graphics.DpiX
Graphics.DpiY
财产。
这样你应该能够正确地计算它(这是我在我的一个项目中如何做到的)。
只需从中创建一个虚拟的Form和一个Graphics对象(如果您的代码是在表单上下文之外执行的),就可以得到这些:

public static SizeF GetCurrentDpi()
{
    using (Form form = new Form())
    using (Graphics g = form.CreateGraphics())
    {
        var result = new SizeF()
        {
            Width = g.DpiX,
            Height = g.DpiY
        };
        return result;
    }
}

Control.CreateGraphics Method
用法:
if (GetWindowRect(p[0].MainWindowHandle, ref Rect))
{
    var bmp = new Bitmap(Rect.Width, Rect.Height);
    Graphics graphics = Graphics.FromImage(bmp);

    // Use the helper function to get the current dpi.
    SizeF dpi = GetCurrentDpi();

    // Calc the scale.
    SizeF scale = new SizeF()
    {
        Width = dpi.Width / 96f,
        Height = dpi.Height / 96f
    };

    // Scale the rectangle.
    Rect.Width *= scale.Width;
    Rect.Height *= scale.Height;

    graphics.CopyFromScreen(Rect.Left, Rect.Top, 0, 0, new Size(Rect.Width, Rect.Height), CopyPixelOperation.SourceCopy);
    bmp.Save(@"C:\Screenshots\temp1.png");
}

演示:
class Program
{
    [DllImport("user32.dll", SetLastError = true)]
    static extern bool GetWindowRect(IntPtr hwnd, ref RECT lpRect);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool ShowWindow(IntPtr hWnd, ShowWindowCommands nCmdShow);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool SetForegroundWindow(IntPtr hWnd);

    static void Main(string[] args)
    {

        RECT rect = new RECT();
        Process[] processes = System.Diagnostics.Process.GetProcessesByName("iexplore");
        Process iexplore = processes.First();

        ShowWindow(iexplore.MainWindowHandle, ShowWindowCommands.Restore);
        SetForegroundWindow(iexplore.MainWindowHandle);
        var result = GetWindowRect(iexplore.MainWindowHandle, ref rect);

        RectangleF rectF = new RectangleF()
        {
            Location = new PointF(rect.Left, rect.Top),
            Size = new SizeF(rect.Right - rect.Left + 1, rect.Bottom - rect.Top + 1)
        };            

        var bmp = new Bitmap((int)rectF.Width, (int)rectF.Height);
        Graphics graphics = Graphics.FromImage(bmp);
        graphics.CopyFromScreen((int)rectF.Left, (int)rectF.Top, 0, 0, new Size((int)rectF.Width, (int)rectF.Height), CopyPixelOperation.SourceCopy);
        bmp.Save(@"C:\temp\screenshot1.jpg", ImageFormat.Jpeg);          
    }      
}

enum ShowWindowCommands
{
    Hide = 0,
    Normal = 1,
    ShowMinimized = 2,
    Maximize = 3,
    ShowMaximized = 3,
    ShowNoActivate = 4,
    Show = 5,
    Minimize = 6,
    ShowMinNoActive = 7,
    ShowNA = 8,
    Restore = 9,
    ShowDefault = 10,
    ForceMinimize = 11
}

[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
    public int Left;
    public int Top;
    public int Right;
    public int Bottom;
}

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