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?
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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

