android项目获取版本号

private String getVersion(){
//得到包管理器
PackageManager packageManager = getPackageManager();
PackageInfo packageInfo = null;
try {
//传入包名
packageInfo = packageManager.getPackageInfo(getPackageName(),0);

} catch (NameNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return packageInfo.versionName;

}