Saturday 8 April 2017

Canvas - accept mousewheel events (WPF)

WPF da Canvas ning MouseWheel eventini handle qilish
 
  Odatda Canvas yaratib, unga ixtiyoriyta Children add qilganimizda
  va undagi MouseWheel eventini qayta ishlashimiz uchun:
     canvas1.Background = Brushes.Transparent; deb olishimiz yoki umumiy olganda
     yaratgan canvas1 objectimizning Background qiymatini o'rnatishimiz kerak;
aks holda MouseWheel event ni hadle qila olmaymiz. Chunki default holatda
Canvas Background siz yaratiladi.
Masalan:
 
  ...

  Canvas canvas1 = new Canvas();
  canvas1.Background = Brushes.Transparent;
  Label label = new Label();
  label.Content = "This is Text";
  label.Foreground = Brushes.Blue;
       label.FontSize = 12;
       label.FontWeight = FontWeights.Bold;
  canvas1.Children.add(label);
  canvas1.MouseWheel+=Canvas1_Mouseheel;
  ...
  void Canvas1_Mouseheel()
  {
  ...
  }

Using Column and Row deffinations in WPF


WPF da Column va Row deffination lardan foydalanish

Window da ishlaganimizda yoki UserControlda ishlaganimizda
uni Row va Column larga ajratgan holda contentlarni joylashtirishimiz mumkin
buning uchun Grid quyidagi tartibda aniqlanishi lozim:
   <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="400" Name="column1"/>
            <ColumnDefinition Width="*" Name="column2"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
</Grid>

Ushubu code yordamida biz Grid ni 2ta Column va 1ta Row ga ajratib yaratdik.
Endi Ixtiyoriy elementni add qilishni qaraymiz. Row yoki Column lar avtomatik
0 dan boshlab indexlangan boladi.

...
<Button x:Name="btnResult" Content="Результать" HorizontalAlignment="Left" Margin="78,16,0,0" VerticalAlignment="Top" Width="75" Click="btnResult_Click"
                Grid.Column="0"/>
<Button x:Name="btnReport" Content="Отчёть" HorizontalAlignment="Left" Margin="78,16,0,0" VerticalAlignment="Top" Width="75" Click="btnReport_Click"
                Grid.Column="1"/>
...

Demak, yuqoridagi code ning ma'nosi shundaki,
btnResult tugmasi 1-columnga add qilindi, btnResult esa 2-Column ga add qilindi.

Bu nima uchun kerak?
 Biz Grid ni Column va Row lar yordamida xoxlagancha bolaklarga ajaratib har bir yacheykasiga content joylashtira olamiz!
Savol: Yacheykalarga Splitter qoyish mumkinmi? Ya'ni mouse bilan uning sizeni change qiboladimi?
 Javob: Albatta boladi!
Masalan:
 <Window x:Class="MySamples.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplicationSample2"
        mc:Ignorable="d"
        Title="MainWindow" Height="728" Width="1024" WindowStartupLocation="CenterScreen"
        WindowState="Maximized">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="400" Name="column1"/>
            <ColumnDefinition Width="*" Name="column2"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>      
       
        <Button x:Name="btnResult" Content="Результать" HorizontalAlignment="Left" Margin="78,16,0,0" VerticalAlignment="Top" Width="75" Click="btnResult_Click"
                Grid.Column="0"/>
        <ListBox Name="listBox1" Margin="0,50,0,0"
                 ItemsSource="{Binding Items}" Grid.Column="0" Width="380" Height="650">
            <ListBox.ItemTemplate>
                <DataTemplate>

                    <StackPanel Orientation="Horizontal" Background="Aqua">
                        <Label Content="{Binding recNo}" Width="100"/>
                        <Button Content="{Binding Path=wellName}" Width="120" Background="AliceBlue"/>
                        <Button>
                            <Button.Content>
                                <TextBlock Text="{Binding Path=x0, StringFormat='X: {0}'}" Width="70"/>
                            </Button.Content>
                        </Button>
                        <Button>
                            <Button.Content>
                                <TextBlock Text="{Binding Path=y0, StringFormat='Y: {0}'}" Width="70"/>
                            </Button.Content>
                        </Button>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <GridSplitter Grid.Column="0"
                        HorizontalAlignment="Right"
                        Background="Green"
                        ShowsPreview="False"
                        Width="5" Height="Auto"/>
        <TextBlock Text="this is second block" Grid.Column="1" Margin="10,0,0,0"/>
        <ScrollViewer Grid.Column="1" CanContentScroll="True" Margin="0,0,0,0"
                      HorizontalAlignment="Left" VerticalAlignment="Top" VerticalScrollBarVisibility="Auto"
                      HorizontalScrollBarVisibility="Auto">

            <Canvas Name="canvas1" Grid.Column="1" Width="1500" Height="950" HorizontalAlignment="Left"
                    VerticalAlignment="Top" Margin="0,0,0,0">
            </Canvas>
        </ScrollViewer>
    </Grid>
</Window>
 

Tasks and Threads

  Differences Between Task And Thread: 1. The Thread class is used for creating and manipulating a thread in Windows.  2. A Task represents ...