我正在开发一款画图应用程序。我使用Canvas控件作为白板。
我想在WPF Canvas中使用InkCanvas类型的功能,这意味着我想在Canvas上自由绘制形状。我该怎么做?我还想将其保存为*.JPG文件。
第二个问题是如何像我们在MS Paint中所做的那样绘制字体?我可以集成FontDialogBox吗?如果可以,怎么做?
感谢您!
<StackPanel>
<Canvas MouseLeftButtonDown="myCanvas_MouseLeftButtonDown" MouseMove="myCanvas_MouseMove"
x:Name="inkCanvas" Width="400" Height="200"> </Canvas>
<Button Height="20" Width="30" x:Name="AddTextBtn" Click="AddTextBtn_Click">AddText</Button>
</StackPanel>
代码后端:
private Point _startPoint;
private Polyline _line;
private void myCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
_startPoint = e.GetPosition(myCanvas);
_line = new Polyline();
_line.Stroke = new SolidColorBrush(Colors.Black);
_line.StrokeThickness = 2.0;
myCanvas.Children.Add(_line);
}
private void myCanvas_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
Point currentPoint = e.GetPosition(myCanvas);
if (_startPoint != currentPoint)
{
_line.Points.Add(currentPoint);
}
}
}
private void AddTextBtn_Click(object sender, RoutedEventArgs e)
{
// Show Font Dialog Box
TextBlock tb = new TextBlock();
tb.FontFamily = new FontFamily("Arial");
tb.FontSize = 14;
tb.Text = "SampleText";
// Set position on canvas:
Canvas.SetTop(tb,100);
Canvas.SetLeft(tb, 50);
myCanvas.Children.Add(tb);
}
但是没有纯WPF字体选择器。您可以使用WinForms中的字体选择器或者查看很多纯Xaml实现的字体选择器,例如此链接
保存为jpg格式:使用RenderTargetBitmap或CroppedBitmap;请参考此处SO链接