CODEWITHSUNDEEP
c#.netwpfxaml
Pawan Kumar Prasad
Pawan Kumar Prasad

Reputation: 57

WPF Rotate line with angle from center point

I am trying to draw lines using WPF and c# and Facing the below problem.

Imaging I have to draw a line with fixed length, I need to rotate this line with the given angle. suppose 45 degree. But the condition is I should rotate this from center point. I am attaching the image for clean understanding.

descriptive image

Can any one please help me to write a C# program.

Upvotes: 0

Views: 6179

Answers (2)

nevermind
nevermind

Reputation: 2448

To rotate the line by a custom angle, apply a RotateTransform to it. You can set RenderTransformOrigin property to 0.5 0.5 to rotate around center point.

<Grid Width="200" Height="200">
    <Line X1="0" Y1="0" X2="1" Y2="0" Stretch="Uniform" Stroke="Blue" StrokeThickness="2" RenderTransformOrigin="0.5 0.5">
        <Line.RenderTransform>
            <RotateTransform Angle="45" />
        </Line.RenderTransform>
    </Line>
</Grid>

If the angle is fixed (e.g. always the same), you can calculate coordinates of the start and end points, and draw a diagonal line without using transform:

<Line X1="0" Y1="0" X2="200" Y2="200" Stroke="Blue" StrokeThickness="2" />

Upvotes: 7

Celso L&#237;vero
Celso L&#237;vero

Reputation: 726

here's the idea, you need to improve it, shape it to what you need

    private void Rotate()
    {
        while (Degrees >= 360)
            Degrees -= 360;
        while (Degrees <= -360)
            Degrees += 360;

        X1 = 0;
        Y1 = 0;
        var rad = Degrees * Math.PI / 180;
        const int radius = 100;
        var sin = Math.Sin(rad);
        var cos = Math.Cos(rad);
        var tan = Math.Tan(rad);

        Y2 = sin * radius;
        X2 = cos * radius;

    }

XAML

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <StackPanel Grid.Row="0" Orientation="Horizontal" >
        <Label Content="Rotation" />
        <TextBox  Text="{Binding Degrees}" Width="50" Margin="5,5,0,5" HorizontalContentAlignment="Right" VerticalContentAlignment="Center"/>
        <Label Content="°" />
        <Button Content="Rotate" Margin="5" Command="{Binding RotateCommand}"/>
    </StackPanel>
    <Grid    Grid.Row="1"  HorizontalAlignment="Center" VerticalAlignment="Center" >
        <Line Stroke="Red" X1="{Binding X1}" X2="{Binding X2}" Y1="{Binding Y1}" Y2="{Binding Y2}"/>
    </Grid>
</Grid>

Upvotes: 3

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