Basically when user resizes my application's window I want application to be same size when application is re-opened again.
At first I though of handling SizeChanged event and save Height and Width, but I think there must be easier solution.
Pretty simple problem, but I can not find easy solution to it.
Save the values in the user.config file.
You'll need to create the value in the settings file - it should be in the Properties folder. Create five values:
Top of type doubleLeft of type doubleHeight of type doubleWidth of type doubleMaximized of type bool - to hold whether the window is maximized or not. If you want to store more information then a different type or structure will be needed.Initialise the first two to 0 and the second two to the default size of your application, and the last one to false.
Create a Window_OnSourceInitialized event handler and add the following:
this.Top = Properties.Settings.Default.Top;
this.Left = Properties.Settings.Default.Left;
this.Height = Properties.Settings.Default.Height;
this.Width = Properties.Settings.Default.Width;
// Very quick and dirty - but it does the job
if (Properties.Settings.Default.Maximized)
{
WindowState = WindowState.Maximized;
}
NOTE: The set window placement needs to go in the on source initialised event of the window not the constructor, otherwise if you have the window maximised on a second monitor, it will always restart maximised on the primary monitor and you won't be able to access it.
Create a Window_Closing event handler and add the following:
if (WindowState == WindowState.Maximized)
{
// Use the RestoreBounds as the current values will be 0, 0 and the size of the screen
Properties.Settings.Default.Top = RestoreBounds.Top;
Properties.Settings.Default.Left = RestoreBounds.Left;
Properties.Settings.Default.Height = RestoreBounds.Height;
Properties.Settings.Default.Width = RestoreBounds.Width;
Properties.Settings.Default.Maximized = true;
}
else
{
Properties.Settings.Default.Top = this.Top;
Properties.Settings.Default.Left = this.Left;
Properties.Settings.Default.Height = this.Height;
Properties.Settings.Default.Width = this.Width;
Properties.Settings.Default.Maximized = false;
}
Properties.Settings.Default.Save();
This will fail if the user makes the display area smaller - either by disconnecting a screen or changing the screen resolution - while the application is closed so you should add a check that the desired location and size is still valid before applying the values.
Actually you don't need to use code-behind to do that (except for saving the settings). You can use a custom markup extension to bind the window size and position to the settings like this :
<Window x:Class="WpfApplication1.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:my="clr-namespace:WpfApplication1"
Title="Window1"
Height="{my:SettingBinding Height}"
Width="{my:SettingBinding Width}"
Left="{my:SettingBinding Left}"
Top="{my:SettingBinding Top}">
You can find the code for this markup extension here : http://www.thomaslevesque.com/2008/11/18/wpf-binding-to-application-settings-using-a-markup-extension/
While you can "roll your own" and manually save the settings somewhere, and in general it will work, it is very easy to not handle all of the cases correctly. It is much better to let the OS do the work for you, by calling GetWindowPlacement() at exit and SetWindowPlacement() at startup. It handles all of the crazy edge cases that can occur (multiple monitors, save the normal size of the window if it is closed while maximized, etc.) so that you don't have to.
This MSDN Sample shows how to use these with a WPF app. The sample isn't perfect (the window will start in the upper left corner as small as possible on first run, and there is some odd behavior with the Settings designer saving a value of type WINDOWPLACEMENT), but it should at least get you started.
There's a NuGet Project RestoreWindowPlace see on github that does all this for you, saving the information in an XML file.
To get it to work on a window, it's as simple as calling:
((App)Application.Current).WindowPlace.Register(this);
In App you create the class that manages your windows. See the github link above for more information.
I made a more generic solution based on RandomEngys brilliant answer. It saves the position to file in the running folder and you don't need to create new properties for each new window you create. This sollution works great for me with minimal code in code behind.
using System;
using System.IO;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows;
using System.Windows.Interop;
using System.Xml;
using System.Xml.Serialization;
namespace WindowPlacementNameSpace
{
// RECT structure required by WINDOWPLACEMENT structure
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
public RECT(int left, int top, int right, int bottom)
{
this.Left = left;
this.Top = top;
this.Right = right;
this.Bottom = bottom;
}
}
// POINT structure required by WINDOWPLACEMENT structure
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int X;
public int Y;
public POINT(int x, int y)
{
this.X = x;
this.Y = y;
}
}
// WINDOWPLACEMENT stores the position, size, and state of a window
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct WINDOWPLACEMENT
{
public int length;
public int flags;
public int showCmd;
public POINT minPosition;
public POINT maxPosition;
public RECT normalPosition;
}
public static class WindowPlacement
{
private static readonly Encoding Encoding = new UTF8Encoding();
private static readonly XmlSerializer Serializer = new XmlSerializer(typeof(WINDOWPLACEMENT));
[DllImport("user32.dll")]
private static extern bool SetWindowPlacement(IntPtr hWnd, [In] ref WINDOWPLACEMENT lpwndpl);
[DllImport("user32.dll")]
private static extern bool GetWindowPlacement(IntPtr hWnd, out WINDOWPLACEMENT lpwndpl);
private const int SW_SHOWNORMAL = 1;
private const int SW_SHOWMINIMIZED = 2;
private static void SetPlacement(IntPtr windowHandle, string placementXml)
{
if (string.IsNullOrEmpty(placementXml))
{
return;
}
byte[] xmlBytes = Encoding.GetBytes(placementXml);
try
{
WINDOWPLACEMENT placement;
using (MemoryStream memoryStream = new MemoryStream(xmlBytes))
{
placement = (WINDOWPLACEMENT)Serializer.Deserialize(memoryStream);
}
placement.length = Marshal.SizeOf(typeof(WINDOWPLACEMENT));
placement.flags = 0;
placement.showCmd = (placement.showCmd == SW_SHOWMINIMIZED ? SW_SHOWNORMAL : placement.showCmd);
SetWindowPlacement(windowHandle, ref placement);
}
catch (InvalidOperationException)
{
// Parsing placement XML failed. Fail silently.
}
}
private static string GetPlacement(IntPtr windowHandle)
{
WINDOWPLACEMENT placement;
GetWindowPlacement(windowHandle, out placement);
using (MemoryStream memoryStream = new MemoryStream())
{
using (XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8))
{
Serializer.Serialize(xmlTextWriter, placement);
byte[] xmlBytes = memoryStream.ToArray();
return Encoding.GetString(xmlBytes);
}
}
}
public static void ApplyPlacement(this Window window)
{
var className = window.GetType().Name;
try
{
var pos = File.ReadAllText(Directory + "\\" + className + ".pos");
SetPlacement(new WindowInteropHelper(window).Handle, pos);
}
catch (Exception exception)
{
Log.Error("Couldn't read position for " + className, exception);
}
}
public static void SavePlacement(this Window window)
{
var className = window.GetType().Name;
var pos = GetPlacement(new WindowInteropHelper(window).Handle);
try
{
File.WriteAllText(Directory + "\\" + className + ".pos", pos);
}
catch (Exception exception)
{
Log.Error("Couldn't write position for " + className, exception);
}
}
private static string Directory => Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
}
}
In your code behind you add these two methods
///This method is save the actual position of the window to file "WindowName.pos"
private void ClosingTrigger(object sender, EventArgs e)
{
this.SavePlacement();
}
///This method is load the actual position of the window from the file
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
this.ApplyPlacement();
}
in the xaml window you add this
Closing="ClosingTrigger"