用eclipse开发android要怎样才能修改版本号

1、打开eclipse

2、在自己创建的项目中找到res,点击打开，点击project.properties，看到

# This file is automatically generated by Android Tools.

# Do not modify this file -- YOUR CHANGES WILL BE ERASED!

#

# This file must be checked in Version Control Systems.

#

# To customize properties used by the Ant build system edit

# "ant.properties", and override values to adapt the script to your

# project structure.

#

# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):

#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt

# Project target.

target=android-21

3、看到最下面一行的android-21了吗？修改这里就行了，当前21指的是android5.0版本，你可以修改数字成19或者其他，19是android4.4的