UC知道vb2008中设置弹出窗口的问题
来源：百度知道 编辑：UC知道 时间：2024/07/07 18:05:46
我想运行一个程序，时间很长，向让它弹出一个正在计算的窗口，显示进度。但是弹出窗口里的任何控件都没了，只留下了一大堆白色的区域，我不知道为什么，怎么解决。代码如下：dialog1为预计弹出的窗口，本身窗体为form2，计算和画图在button1按钮中实现。
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim gr As Graphics = bg.CreateGraphics
Dim theta, r, xn, yn As Double
Dim brush As SolidBrush
Dim data(bg.Width, bg.Height) As Double
Dialog1.Show()
Dim mycolor As Color
Dim p, pp, qq As Double
Dim dmax = 0.0, dmin = 1.0, diff
gr.Clear(bg.BackColor)
mm = Val(min.Text)
ll = Val(lin.Text)
nn = Val(nin.Text)
For x = 1 To bg.Width
For y = 1 To bg.Height
st = x
xn = x - bg.Width / 2
yn = y - bg.Height / 2
theta = Math.Atan(xn / yn)
If xn <
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim gr As Graphics = bg.CreateGraphics
Dim theta, r, xn, yn As Double
Dim brush As SolidBrush
Dim data(bg.Width, bg.Height) As Double
Dialog1.Show()
Dim mycolor As Color
Dim p, pp, qq As Double
Dim dmax = 0.0, dmin = 1.0, diff
gr.Clear(bg.BackColor)
mm = Val(min.Text)
ll = Val(lin.Text)
nn = Val(nin.Text)
For x = 1 To bg.Width
For y = 1 To bg.Height
st = x
xn = x - bg.Width / 2
yn = y - bg.Height / 2
theta = Math.Atan(xn / yn)
If xn <
弹出窗口里的任何控件都没了，只留下了一大堆白色的区域，是因为你的 Button1_Click 过程时间很长，在退出此过程前，系统没有机会进行绘图操作。
在以下两个循环体内的地方添加语句 DoEvents 能解决你的问题：
For x = 1 To bg.Width
For y = 1 To bg.Height
DoEvents '新添加的语句
st = x
..............
For x = 1 To bg.Width
For y = 1 To bg.Height
DoEvents '新添加的语句
brush = Brushes.Blue()
.....................
button1点击后运行循环过多,计算时占用太多资源,或者Dialog1弹出窗体本身加载东西多,等一段时间,等运行完了,或加载完毕,才能正常显示.
解决的办法是优化运算方法,或少加载控件.
再难一点方法就是用不同的线程同时工作.
(题外话:VS2008本身就很慢,一般的机子吃不消.我因不能忍受它的速度.而把它御载了,重新安装VS2005,觉得VS2005的速度还行.)
改成
dialog1.ShowDialog();
就可以达到你的目的了.
Show()方法不会挂起当前的Form,而是继续执行之后的语句,而且dialog1里面的语句也同时被执行.