gradle针对版本号的管理——任务模式，直接修改build.gradle文件

// 版本号自增
task('increaseVersionCode') << {
def buildFile = file("build.gradle")
def pattern = Pattern.compile("versionCode\\s+(\\d+)")
def manifestText = buildFile.getText()
def matcher = pattern.matcher(manifestText)
matcher.find()
def versionCode = Integer.parseInt(matcher.group(1))
def manifestContent = matcher.replaceAll("versionCode " + ++versionCode)
buildFile.write(manifestContent)
}

// 版本号自增
tasks.whenTaskAdded { task ->
if (task.name.matches('assemble.*?Release')) {
task.dependsOn 'increaseVersionCode'
}
}