for-next执行速度太慢的问题，受不了了

pcdoor · 发表于 2013-2-19 22:03:05

Private yuanshi() As String '定义成模块变量

Private Sub Form_Load()
Dim i As Integer, j As Integer
Dim abcd As Long
abcd = Len(Text2(0).Text)
reDim yuanshi(1 To abcd) As String
i = 1
For j = 1 To abcd
If Mid(Text2(0).Text, j, 1) <> Chr(10) And Mid(Text2(0).Text, j, 1) <> Chr(13) Then
yuanshi(i) = Mid(Text2(0).Text, j, 1)
i = i + 1
End If
Next j
end sub
Text2(0).Text中的内容为附件文件中的内容，(包含空格)大约有32000个字符，该段程序目的是要将Text2(0).Text中内容的有效字符逐字读入数组yuanshi()中，但是程序在执行时耗时近20秒，让人无法承受，请高手们支招一下，看看有没有什么更高效率的方法来实现。

acme_pjz · 发表于 2013-2-19 23:37:32

Dim s As String
s=Text2(0).Text
然后后面所有Text2(0).Text都替换成s，这样应该会快一些

pcdoor · 发表于 2013-2-20 15:19:51

是的，程序执行效率显著提高，谢谢各位高手指点！

sexfio · 发表于 2013-2-20 18:55:45

s$ =Text2(0).Text
s= replace(s,vbcr,vbnullstring)
s= replace(s,vblf,vbnullstring)
n& = len(s)
redim b(n-1)
for i = 1 to n
b(i-1) = mid$(s,i,1)
next

我猜replace的速度应该比你1个1个比对要快

VBProFan · 发表于 2013-2-20 19:35:05

Option Explicit
Private yuanshi() As String '定义成模块变量
Private Sub Command1_Click()
Dim i As Integer, j As Integer
Dim L As Long
Dim st As Single
st = Timer
L = Len(txt.Text)
ReDim yuanshi(1 To L) As String
i = 1
For j = 1 To L
If Mid(txt.Text, j, 1) <> Chr(10) And Mid(txt.Text, j, 1) <> Chr(13) Then
yuanshi(i) = Mid(txt.Text, j, 1)
i = i + 1
End If
Next j
Debug.Print Timer - st
MsgBox Timer - st
End Sub
Private Sub Command2_Click()
Dim i As Integer, j As Integer
Dim L As Long
Dim st As Single
Dim s As String
st = Timer
s = txt.Text
L = Len(s)
ReDim yuanshi(1 To L) As String
i = 1
For j = 1 To L
If Mid(s, j, 1) <> Chr(10) And Mid(s, j, 1) <> Chr(13) Then
yuanshi(i) = Mid(s, j, 1)
i = i + 1
End If
Next j
Debug.Print Timer - st
MsgBox Timer - st
End Sub
Private Sub Command3_Click()
Dim i As Integer, j As Integer
Dim L As Long
Dim st As Single
Dim s As String
Dim Ch As String * 1
st = Timer
s = txt.Text
L = Len(s)
ReDim yuanshi(1 To L) As String
i = 1
For j = 1 To L
Ch = Mid(s, j, 1)
If Ch <> Chr(10) And Ch <> Chr(13) Then
yuanshi(i) = Ch
i = i + 1
End If
Next j
Debug.Print Timer - st
MsgBox Timer - st
End Sub
Private Sub Command4_Click()
Dim i As Integer
Dim L As Long
Dim st As Single
Dim s As String
Dim Ch As String * 1
st = Timer
s = Replace(txt.Text, vbCrLf, "")
L = Len(s)
ReDim yuanshi(1 To L) As String
For i = 1 To L
yuanshi(i) = Mid(s, i, 1)
Next i
Debug.Print Timer - st
MsgBox Timer - st
End Sub
Private Sub Command5_Click()
Dim i As Integer
Dim L As Long
Dim st As Single
Dim s As String
Dim Ch As String * 1
st = Timer
s = Replace(txt.Text, vbCrLf, "")
L = Len(s)
ReDim org(1 To L) As Byte
org = s
Debug.Print Timer - st
MsgBox Timer - st
End Sub

复制代码

IDE:

Command1_Click
22.75
22.57031
22.55469

Command2_Click
.03125
.046875
.0390625

Command3_Click
.0390625
.046875
.0390625

Command4_Click
.0078125
.0234375
.0234375

Command5_Click
0
0
0

按速度优化 exe:

Command1_Click
22.64844
22.25
22.33594

Command2_Click
.0390625
.0390625
.0390625

Command3_Click
.0390625
.0390625
.0390625

Command4_Click
.0234375
.015625
.0234375

Command5_Click
0
0
0

看来编译器的优化不够啊，反复读控件属性的代码不会替换为内存变量。不过仔细想想不优化这个也是有道理的，万一第二次读 txt.Text 的时候它的值发生了变化那就错误了。

lowxiong · 发表于 2013-2-21 08:52:04

一句yuanshi=split(text2(0),vbcrlf)就可以全部解决，顶多几毫秒。

VBProFan · 发表于 2013-2-21 16:13:09

@sailingzyf3.0 ⊙_⊙b 你写了结果，我当然知道运行过，我的意思是：文件30多K，长度大概是39000，i的值最大也是39000多，为啥integer的i、j没有溢出。能把读取文件的部分贴出来看看么，我和自己的对比下。

汗，幸好你提醒，不然我都没发现问题。我是复制粘贴进文本框的，被自动截断了，看来楼主的电脑才是真的强

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