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在WPF中将坐标从图像控件转换到图像源

stretch image wpf c#

7

Gabriel · 技术社区 · 16 年前

Stretch

<Image Name="imageCtrl" Source="{Binding MyImage}" Stretch="{Binding ImageStretch}" />

当用户在图像上移动鼠标时,我想确定鼠标相对于

void imageCtrl_MouseMove(object sender, MouseEventArgs e)
{
    Point locationInControl = e.GetPosition(imageCtrl);
    Point locationInImage = ???
    updateImage(locationInImage);
}

Source ActualSize imageCtrl.Stretch

Point ImgControlCoordsToPixelCoords(Point locInCtrl, 
    double imgCtrlActualWidth, double imgCtrlActualHeight)
{
    if (ImageStretch == Stretch.None)
        return locInCtrl;

    Size renderSize = new Size(imgCtrlActualWidth, imgCtrlActualHeight);
    Size sourceSize = bitmap.Size;

    double xZoom = renderSize.Width / sourceSize.Width;
    double yZoom = renderSize.Height / sourceSize.Height;

    if (ImageStretch == Stretch.Fill)
        return new Point(locInCtrl.X / xZoom, locInCtrl.Y / yZoom);

    double zoom;
    if (ImageStretch == Stretch.Uniform)
        zoom = Math.Min(xZoom, yZoom);
    else // (imageCtrl.Stretch == Stretch.UniformToFill)
        zoom = Math.Max(xZoom, yZoom);

    return new Point(locInCtrl.X / zoom, locInCtrl.Y / zoom);
}

1 回复 | 直到 16 年前

1

8

Steven 15 年前

<Viewbox Stretch="{Binding ImageStretch}">
    <Image Name="imageCtrl" Source="{Binding MyImage}" Stretch="None"/>
</Viewbox>

void imageCtrl_MouseMove(object sender, MouseEventArgs e) 
{ 
    Point locationInControl = e.GetPosition(imageCtrl);
}