vb如何修改txt文档的某一行的具体内容

Question

txt文档内容如下:
finish
/clear
/filname,menjiashiyan
/title,menjiashiyan

y=-500
f=-50000
/prep7
et,1,shell63
r,1,6
mp,ex,1,2.1e5
mp,nuxy,1,0.3
mp,dens,1,7.85e-6

k,1,0,0,0
k,2,9400,0,0
k,3,9400,0,300
k,4,0,0,300
k,5,0,y,0
k,6,9400,y,0
k,7,9400,y,300
k,8,0,y,300
k,9,7060,y,0
......
要修改第六行的f=-50000为f="为任意在vb界面中输入的数"
如何修改，请附具体代码与解释，本人对vb不熟

Answer 1

假设你的文件名为“C:\a1.txt”
dim txt as string
Open "C:\a1.txt" for input as #1
Open "C:\a2.txt" for output as #2
do while not eof(1)
line input #1, txt
if txt="f=-50000" then txt="f=" & Text1.Text
print #2,txt
loop
close
运行结束后，a2.txt中就是修改后的文件。本回答被提问者采纳

Answer 2

InStrRev(StrConv(FileMe, vbUnicode), "f=") '检测是否有f=