问题描述
我正在尝试使用Winform或WPF Windows编写放大镜应用程序.想法是将窗口拖到屏幕上的某个位置上并放大.我知道它在商业上存在,但需要构建定制版本.我面临的挑战是捕获活动应用程序后面的屏幕图像.我在下面找到了捕获屏幕图像的代码.但其中包含活动窗口
I'm trying to write a magnifier application using a winform or wpf windows. The idea is to drag the window over a spot on the screen and magnify it. I know it exists commercially but need to build a customized version. The challenge I'm having is to capture the screen image behind the active application.I have found code to capture a screen image below. But it includes the active window
{
Rectangle bounds = new Rectangle(this.Location, this.Size);
Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height);
Graphics g = Graphics.FromImage(bitmap);
g.CopyFromScreen(this.Location, Point.Empty, bounds.Size);
Bitmap bp2 = new Bitmap(bitmap); // local copy of image...
pictureBox1.Image = bp2;
}
添加语句以隐藏活动的应用程序可以纠正图像捕获,但是会引起屏幕闪烁,我想避免这种情况.(下面的代码已修改)
Adding statements to hide the active application correct the image capture, but introduce a screen flicker which I'd like to avoid. (modified code below)
{
this.StartPosition = FormStartPosition.Manual; // get current window location
Point cur = this.Location;
this.Location = new Point(-500, -500); // hide the active app off screen.
Rectangle bounds = new Rectangle(cur, this.Size);
Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height);
Graphics g = Graphics.FromImage(bitmap);
g.CopyFromScreen(cur, Point.Empty, bounds.Size);
Bitmap bp2 = new Bitmap(bitmap); // local copy of image...
pictureBox1.Image = bp2;
this.Location = cur; // restore application location
}
有人可以建议在活动窗口后面捕获屏幕区域的替代方法吗?
Can someone suggest an alternative to capture a screen region, behind an active windows?
谢谢.
推荐答案
包装放大API非常有用.我创建了一个Winforms控件来执行此操作.在您的项目中添加一个新类,并粘贴以下代码.编译.将新控件从工具箱的顶部拖放到窗体上.
Wrapping the Magnification API is pretty useful. I created a Winforms control that does this. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto a form.
TrackMouse属性控制屏幕的哪个部分被放大显示.设置为False时,它将放大控件所覆盖的区域,使其像放大镜一样起作用.设置为True,它将跟随鼠标,像Windows的放大镜一样工作.
The TrackMouse property controls which part of the screen is shown magnified. Set to False, it magnifies the area covered by the control, making it act like a magnifying glass. Set to True, it will operate like Windows' Magnifier, following the mouse.
放大倍率"属性控制放大倍数.您已经可以使用鼠标滚轮对其进行调整.
The Magnification property controls the amount of magnification. You can already adjust it by using the mouse wheel.
您放置的表单的TopMost属性应设置为True.您可能需要修改其Region属性,使其类似于望远镜.
The form you drop it should have its TopMost property set to True. You might want to tinker with its Region property to make it resemble a spyglass.
using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
class Magnifier : Control {
public Magnifier() {
if (!MagInitialize()) throw new NotSupportedException();
timer = new Timer { Interval = 45 };
timer.Tick += (o, ea) => { if (trackMouse) setSource(false); else Invalidate(); };
}
[DefaultValue(false)]
public bool TrackMouse {
get { return trackMouse; }
set { trackMouse = value; setSource(false); }
}
[DefaultValue(2.0f)]
public float Magnification {
get { return magnification; }
set { magnification = Math.Max(1, value); setSource(true); }
}
protected override CreateParams CreateParams {
get {
var cp = base.CreateParams;
if (!this.DesignMode) {
cp.ClassName = "Magnifier";
//cp.Style |= MS_SHOWMAGNIFIEDCURSOR;
this.SetStyle(ControlStyles.UserPaint, true);
}
return cp;
}
}
protected override void OnHandleCreated(EventArgs e) {
base.OnHandleCreated(e);
if (!this.DesignMode) {
setSource(true);
this.FindForm().LocationChanged += ParentLocationChanged;
timer.Start();
}
}
protected override void Dispose(bool disposing) {
if (disposing) {
var frm = this.FindForm();
if (frm != null) frm.LocationChanged -= ParentLocationChanged;
timer.Dispose();
MagUninitialize();
}
base.Dispose(disposing);
}
private void ParentLocationChanged(object sender, EventArgs e) {
if (!trackMouse) setSource(false);
}
protected override void OnSizeChanged(EventArgs e) {
setSource(false);
base.OnSizeChanged(e);
}
protected override void OnMouseWheel(MouseEventArgs e) {
this.Magnification += e.Delta / 100f;
((HandledMouseEventArgs)e).Handled = true;
}
private void setSource(bool newmag) {
if (!this.IsHandleCreated || this.DesignMode) return;
if (newmag) {
var xform = new MAGTRANSFORM();
xform.v11 = xform.v22 = magnification;
xform.v33 = 1.0f;
MagSetWindowTransform(this.Handle, ref xform);
}
Point center;
if (trackMouse) center = Cursor.Position;
else {
var rc = this.RectangleToScreen(this.Bounds);
center = new Point(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2);
}
var scr = Screen.FromPoint(center);
var rect = new RECT();
rect.left = Math.Max(scr.Bounds.Left, center.X - (int)(this.Width / magnification / 2));
rect.top = Math.Max(scr.Bounds.Top, center.Y - (int)(this.Height / magnification / 2));
rect.right = rect.left + (int)(this.Width / magnification);
if (rect.right > scr.Bounds.Right) {
rect.right = scr.Bounds.Right;
rect.left = rect.right - (int)(this.Width / magnification);
}
rect.bottom = center.Y + (int)(this.Height / magnification);
if (rect.bottom > scr.Bounds.Bottom) {
rect.bottom = scr.Bounds.Bottom;
rect.top = rect.bottom - (int)(this.Height / magnification);
}
MagSetWindowSource(this.Handle, ref rect);
this.Invalidate();
}
private Timer timer;
private bool trackMouse;
private float magnification = 2.0f;
private struct RECT {
public int left, top, right, bottom;
}
private struct MAGTRANSFORM {
public float v11, v12, v13;
public float v21, v22, v23;
public float v31, v32, v33;
}
[DllImport("magnification.dll")]
private static extern bool MagInitialize();
[DllImport("magnification.dll")]
private static extern bool MagUninitialize();
[DllImport("magnification.dll")]
private static extern bool MagSetWindowSource(IntPtr hWnd, ref RECT rc);
[DllImport("magnification.dll")]
private static extern bool MagSetWindowTransform(IntPtr hWnd, ref MAGTRANSFORM xform);
private const int MS_SHOWMAGNIFIEDCURSOR = 1;
private const int MS_CLIPAROUNDCURSOR = 2;
private const int MS_INVERTCOLORS = 4;
}
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