Mạnh mẽ nhất của bảng được xây dựng trong. Thực hiện không có bố trí logic đặt các trẻ em nơi bạn nói với nó, cho phép bạn điều khiển hoàn toàn của quá trình bố trí. Sắp xếp trẻ em trong một mạng lưới mà mỗi tế bào có cùng kích thước. | Example 5-13. Exploiting the content model in a tool tip TextBox Width 100 TextBlock FontSize 25 Ellipse Fill Orange Width 20 Height 20 Plain text is Italic so Italic Span FontFamily Old English Text MT last century Span ellipse Fill Orange Width 20 Height 20 TextBlock TextBox Figure 5-15 shows the results. Note that the tool tip will normally close as soon as the mouse pointer moves over it. This means that although it is possible to put interactive elements such as buttons inside a tool tip it s not typically a useful thing to do because it s not possible to click on them. However it is possible to subvert the auto-close behavior you can force the tool tip to open before the user hovers over the target by setting its IsOpen property to True. This causes the tool tip to open immediately and to remain open for as long as the target element s window has the focus. Or if you set IsOpen to True and also set StaysOpen to False it will open immediately and remain open until you click somewhere outside of the tool tip. In these cases you could host interactive content inside a tool tip. I__ Plain text is so laốt century Figure 5-15. ToolTip with mixed content The ToolTip is shown in its own top-level window. This is useful for tool tips on elements near the edge of your window if the tool tip is large enough that it flows outside of the main window it won t be cropped. GroupBox and Expander GroupBox and Expander are very similar controls both provide a container for arbitrary content and a place for a header on top. Figure 5-16 shows both controls. Aside from their different appearances the main difference between these controls is that the Expander can be expanded and collapsed the user can click on the arrow at the top left to hide and show the content. A GroupBox always shows its content. Both controls derive from HeaderedContentControl which in turn derives from ContentControl. So we can place whatever .
