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标题: [文件操作] for中用SET设置变量后不生效，第2次执行才生效 [打印本页]

作者: keetian 时间: 2015-2-7 12:24 标题: for中用SET设置变量后不生效，第2次执行才生效

@echo off

set "wmpfile=C:\Program Files\Windows Media Player\wmplayer.exe"
if not exist "%wmpfile%" (
echo 未安装Windows Media Player 11...
)
if exist "%wmpfile%" (
for /f "tokens=5" %%i in ('filever.exe "%wmpfile%"') do SET wmpver=%%i
echo 已安装Windows Media Player "%wmpver%"
)

以上代码存为f.bat,在cmd窗口中，第一次执行f.bat,输出已安装Windows Media Player ""
第一次执行f.bat,输出已安装Windows Media Player "10.0.0.3802"
请问怎么解决呢？

作者: pcl_test 时间: 2015-2-7 12:41

回复 1# keetian

@echo off
setlocal enabledelayedexpansion
set "wmpfile=C:\Program Files\Windows Media Player\wmplayer.exe"
if not exist "%wmpfile%" (
echo 未安装Windows Media Player ...
) else (
for /f "tokens=5" %%i in ('filever.exe "%wmpfile%"') do SET wmpver=%%i
echo 已安装Windows Media Player !wmpver!
)
pause
复制代码

作者: DAIC 时间: 2015-2-7 14:23

@echo off
setlocal enabledelayedexpansion
set "wmpfile=C:\Program Files\Windows Media Player\wmplayer.exe"
if not exist "%wmpfile%" (
    echo 未安装Windows Media Player ...
) else (
    for /f "tokens=5" %%i in ('filever.exe "%wmpfile%"') do (
        set "wmpver=%%i"
    )
    echo 已安装Windows Media Player !wmpver!
)
pause
复制代码

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