上一篇blog讲了制作简单的样式的窗体，对于一个传统的窗体，不仅仅可以拖动，和关闭操作、还具有最大化、最小化、隐藏，以及改变窗体的大小等。这篇blog就是对上篇的补充，完善窗体的改变大小和最大化最小化的功能。
1.改变形状窗体的尺寸
实现的效果：在窗体的右下角，当鼠标划过时，改为可以拉动的鼠标样式，根据鼠标拖动的位置，修改窗体的大小。
上篇降到窗体分成两部分，head和content，在这里做一下修改，再增加一行footer，设置高度为5，用于放置一个元素，位置在右下侧，用于截获鼠标事件。
代码如下：
<Grid Grid.Row="2" Background="White">
<Border Height="5" Width="5" Background="White" CornerRadius="500,0,0,0" VerticalAlignment="Bottom" HorizontalAlignment="Right" Cursor="SizeNWSE" MouseLeftButtonDown="Border_MouseLeftButtonDown" MouseLeftButtonUp="Border_MouseLeftButtonUp" MouseMove="Border_MouseMove">
</Border>
</Grid>
其中Border就是用来专门截获鼠标事件的，当鼠标放置在此元素上时，鼠标状态改为可以拖动大小的图标。
在此元素上添加三个事件，鼠标左键按下，释放，和移动。
代码：
//拖动改变窗体大小
bool isWiden = false;
private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
isWiden = true;
}
private void Border_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
isWiden = false;
Border b = (Border)sender;
b.ReleaseMouseCapture();
}
private void Border_MouseMove(object sender, MouseEventArgs e)
{
Border b = (Border)sender;
if (isWiden)
{
b.CaptureMouse();
double newWidth = e.GetPosition(this).X + 5;
double newheight = e.GetPosition(this).Y + 5;
if (newWidth > 0)
{
this.Width = newWidth;
}
if (newheight > 0)
{
this.Height = newheight;
}
}
}
ok ！修改窗体尺寸就实现了。
2.最大化、最小化
最小化的实现可以直接修改窗体的WindowState=WindowState.Minimized;
如果直接修改窗体的WindowState=WindowState.Maximized;确实实现了窗体的最大化，但是存在一个问题，就是窗体的WindowStyle="None"的情况下，上面方式实现的最大化会覆盖系统的任务栏。
那就采用另一种简单的方式，根据活动区域的大小来设置窗体的高和宽，实现最大化的效果。
具体代码如下：
Rect rc = SystemParameters.WorkArea;//获取工作区大小
this.Left = 0;//设置位置
this.Top = 0;
this.Width = rc.Width;
this.Height = rc.Height;
再次点击最大化按钮就会还原到窗体原来的大小和位置，在实现最大化之前需要纪录窗体当前的位置和大小。以便进行还原。
代码如下：
rcnormal = new Rect(this.Left, this.Top, this.Width, this.Height);//保存下当前位置与大小
this.Left = rcnormal.Left;
this.Top = rcnormal.Top;
this.Width = rcnormal.Width;
this.Height = rcnormal.Height;
ok，到这里一个窗体基本有的功能都实现了。我在这里写下的只是一种实现方式，还有很多种可以去尝试。（参考WPF编程宝典（2010））
工程就不打包了，代码贴下：
XAML：
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfAppBlog.MainWindow"
x:Name="Window" Background="Transparent" MinWidth="640" MinHeight="480"
Title="MainWindow" AllowsTransparency="True" WindowStyle="None"
>
<Window.Resources>
<Style x:Key="myBtnStyle" TargetType="{x:Type Button}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition x:Name="columnDefinition1" Width="0.982*"/>
<ColumnDefinition x:Name="columnDefinition" Width="0.018*"/>
</Grid.ColumnDefinitions>
<Rectangle x:Name="rectangle" RadiusY="2" RadiusX="2" Stroke="{x:Null}" Fill="#FF0DAD5F" Grid.ColumnSpan="2"/>
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsFocused" Value="True">
<Setter Property="Stroke" TargetName="rectangle" Value="{x:Null}"/>
<Setter Property="Fill" TargetName="rectangle" Value="#FF0DAD5F"/>
</Trigger>
<Trigger Property="IsDefaulted" Value="True">
<Setter Property="Fill" TargetName="rectangle" Value="#FF0DAD5F"/>
<Setter Property="Stroke" TargetName="rectangle" Value="{x:Null}"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="rectangle" Value="{x:Null}"/>
<Setter Property="Fill" TargetName="rectangle" Value="#FF83D245"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" TargetName="rectangle" Value="{x:Null}"/>
<Setter Property="Fill" TargetName="rectangle" Value="#FF17D256"/>
<Setter Property="Width" TargetName="columnDefinition" Value="Auto"/>
<Setter Property="MinWidth" TargetName="columnDefinition" Value="0"/>
<Setter Property="Width" TargetName="columnDefinition1" Value="*"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Stroke" TargetName="rectangle" Value="{x:Null}"/>
<Setter Property="Fill" TargetName="rectangle" Value="{x:Null}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Border BorderBrush="#FF0DAD5F" BorderThickness="3" CornerRadius="4">
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="30"></RowDefinition>
<RowDefinition></RowDefinition>
<RowDefinition Height="5"></RowDefinition>
</Grid.RowDefinitions>
<Border Background="#FF0DAD5F" BorderBrush="Transparent" MouseDown="Grid_MouseDown" CornerRadius="2,2,0,0">
<Grid Name="Title" Margin="0">
<TextBlock HorizontalAlignment="Left" VerticalAlignment="Center"> My window</TextBlock>
<Button Content="一" Name="btnMin" Click="btnMin_Click" HorizontalAlignment="Right" Foreground="White" Margin="0,0,45,0" Height="20" Width="20" Style="{DynamicResource myBtnStyle}" VerticalAlignment="Center" />
<Button Content="口" Name="btnMaxOrMin" Click="btnMaxOrMin_Click" HorizontalAlignment="Right" Foreground="White" Margin="0,0,25,0" Height="20" Width="20" Style="{DynamicResource myBtnStyle}" VerticalAlignment="Center" />
<Button Content="X" HorizontalAlignment="Right" Foreground="White" Margin="0,0,5,0" Height="20" Width="20" Style="{DynamicResource myBtnStyle}" VerticalAlignment="Center" Click="Button_Click" />
</Grid>
</Border>
<Grid Grid.Row="1" Background="White" >
<Button Content="Button" Height="36" Width="120" Margin="130,127,209,0" Style="{DynamicResource myBtnStyle}" VerticalAlignment="Top"/>
</Grid>
<Grid Grid.Row="2" Background="White">
<Border Height="5" Width="5" Background="White" CornerRadius="500,0,0,0" VerticalAlignment="Bottom" HorizontalAlignment="Right" Cursor="SizeNWSE" MouseLeftButtonDown="Border_MouseLeftButtonDown" MouseLeftButtonUp="Border_MouseLeftButtonUp" MouseMove="Border_MouseMove">
</Border>
</Grid>
</Grid>
</Border>
</Window>
后台：
/// <summary>
/// MainWindow.xaml 的交互逻辑
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
this.InitializeComponent();
// 在此点下面插入创建对象所需的代码。
}
private void Button_Click(object sender, RoutedEventArgs e)
{
this.Close();
}
private void Grid_MouseDown(object sender, MouseButtonEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
DragMove();
}
}
//拖动改变窗体大小
bool isWiden = false;
Rect rcnormal;//定义一个全局rect记录还原状态下窗口的位置和大小。
private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
isWiden = true;
}
private void Border_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
isWiden = false;
Border b = (Border)sender;
b.ReleaseMouseCapture();
}
private void Border_MouseMove(object sender, MouseEventArgs e)
{
Border b = (Border)sender;
if (isWiden)
{
b.CaptureMouse();
;
;
)
{
this.Width = newWidth;
}
)
{
this.Height = newheight;
}
}
}
private void btnMin_Click(object sender, RoutedEventArgs e)
{
this.WindowState = WindowState.Minimized;
}
private void btnMaxOrMin_Click(object sender, RoutedEventArgs e)
{
Rect rc = SystemParameters.WorkArea;//获取工作区大小
if (this.Width == rc.Width)
{
this.Left = rcnormal.Left;
this.Top = rcnormal.Top;
this.Width = rcnormal.Width;
this.Height = rcnormal.Height;
}
else
{
rcnormal = new Rect(this.Left, this.Top, this.Width, this.Height);//保存下当前位置与大小
;//设置位置
;
this.Width = rc.Width;
this.Height = rc.Height;
}
}
}
效果图：（鼠标放置在右下角，修改窗体尺寸）
