前言
接着上周写的截图控件继续更新添加 文字。
1.WPF实现截屏「仿微信」
2.WPF 实现截屏控件之移动（二）「仿微信」
3.WPF 截图控件之伸缩(三) 「仿微信」
4.WPF 截图控件之绘制方框与椭圆(四) 「仿微信」
5.WPF 截图控件之绘制箭头(五)「仿微信」
6.WPF 截图控件之绘制箭头禁止越界(六)「仿微信」
正文
一、接着ScreenCut继续发电。
1）添加文字操作只允许在可编辑区域内
- 在添加文字、使用
Border嵌套TextBox
Border需注意：
1）当控件的高存放不下内容的时候需要将控件的SetTop设置向上移动，最大不能超过Rect的Top 需要监听宽高发生变化SizeChanged
TextBox需注意：
1）需要监听失去光标焦点LostKeyboardFocus后找TextBox的父控件设置边框为零。
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void DrawText() { if (pointStart.Value.X < rect.Right && pointStart.Value.X > rect.Left && pointStart.Value.Y > rect.Top && pointStart.Value.Y < rect.Bottom) { var currentWAndX = pointStart.Value.X + 40; if (textBorder == null) { textBorder = new Border { BorderBrush = _currentBrush == null ? Brushes.Red : _currentBrush, BorderThickness = new Thickness(1), Tag = _tag }; var textBox = new TextBox(); textBox.Style = null; textBox.Background = null; textBox.BorderThickness = new Thickness(0); textBox.Foreground = textBorder.BorderBrush; textBox.FontFamily = DrawingContextHelper.FontFamily; textBox.FontSize = 16; textBox.TextWrapping = TextWrapping.Wrap; textBox.FontWeight = FontWeights.Bold; textBox.MinWidth = _width; textBox.MaxWidth = rect.Right - pointStart.Value.X; textBox.MaxHeight = rect.Height; textBox.Cursor = Cursors.Hand; textBox.Padding = new Thickness(4); textBox.LostKeyboardFocus += (s, e1) => { var tb = s as TextBox; var parent = VisualTreeHelper.GetParent(tb); if (parent != null && parent is Border border) { border.BorderThickness = new Thickness(0); if (string.IsNullOrWhiteSpace(tb.Text)) _canvas.Children.Remove(border); } }; textBorder.SizeChanged += (s, e1) => { var tb = s as Border; var y = y1; if (y + tb.ActualHeight > rect.Bottom) { var v = Math.Abs(rect.Bottom - (y + tb.ActualHeight)); y1 = y - v; Canvas.SetTop(tb, y1); } }; textBorder.PreviewMouseLeftButtonDown += (s, e) => { SelectElement(); var border = s as Border; border.BorderThickness = new Thickness(1); frameworkElement = border; frameworkElement.Opacity = .7; }; textBorder.Child = textBox; _canvas.Children.Add(textBorder); textBox.Focus(); var x = pointStart.Value.X; if (currentWAndX > rect.Right) x = x - (currentWAndX - rect.Right); Canvas.SetLeft(textBorder, x); Canvas.SetTop(textBorder, pointStart.Value.Y); } } } 2）移除焦点 。
Keyboard.ClearFocus(); 完整代码如下
