FoxPro的垂直滚动选框

时间:2020-03-06 14:32:26  来源:igfitidea点击:

谁能为我指出一些代码/为我提供有关如何为VFP 8或者9创建平滑滚动垂直选框的想法?

任何帮助表示赞赏。

解决方案

我们可以使用可滚动容器

这是一个可以滚动消息的快速程序。将以下内容放入prg文件中并运行它。

我将containerScrollArea作为一个封装计时器,标签和滚动代码的类。给它GetNextMessage方法,我们可以重写该方法以检索消息。

* Put a container on the screen to hold our scroller
_screen.AddObject("containerScrollArea", "container")

WITH _Screen.containerScrollArea
    * Size it
    .Visible = .t.
    .Width = 100
    .Height = 100

    * Add two labels, one to hold each scrolling message
    .AddObject("labelScroll1", "Label") 
    .AddObject("labelScroll2", "Label") 

    * This timer will move the labels to scroll them
    .AddObject("timerScroller", "ScrollTimer")
ENDWITH

WITH _Screen.containerScrollArea.labelScroll1
    * The labels are positioned below the margin of the container, so they're not initially visible
    .Top = 101
    .Height = 100
    .Visible = .t.
    .WordWrap = .t.
    .BackStyle= 0
    .Caption = "This is the first scrolling text, which is scrolling."
ENDWITH

WITH _Screen.containerScrollArea.labelScroll2
    * The labels are positioned below the margin of the container, so they're not initially visible
    .Top = 200
    .Height = 100
    .Visible = .t.
    .WordWrap = .t.
    .BackStyle= 0
    .Caption = "This is the second scrolling text, which is scrolling."
ENDWITH

* Start the timer, which scrolls the labels
_Screen.containerScrollArea.timerScroller.Interval = 100

DEFINE CLASS ScrollTimer AS Timer
    PROCEDURE Timer

        * If the first label is still in view, move it by one pixel
        IF This.Parent.labelScroll1.Top > -100
            This.Parent.labelScroll1.Top = This.Parent.labelScroll1.Top - 1
        ELSE
            * If the first label has scrolled out of view on the top of the container, move it back to the bottom.
            This.Parent.labelScroll1.Top = 101
            * Load some new text here
        ENDIF

        IF This.Parent.labelScroll2.Top > -100
            * If the second label is still in view, move it by one pixel
            This.Parent.labelScroll2.Top = This.Parent.labelScroll2.Top - 1
        ELSE
            * If the second label has scrolled out of view on the top of the container, move it back to the bottom.
            This.Parent.labelScroll2.Top = 101
            * Load some new text here
        ENDIF
    ENDPROC
ENDDEFINE

不幸的是,我的工作性质使我没有时间去研究图形,但是如果我愿意的话,我会考虑在VFP中使用GDI +。这是一篇文章,可以入门