gradle中这些任务定义语法之间的区别是什么？ [英] What is the difference between these task definition syntaxes in gradle?

问题描述

A）

 任务建立<< {
 description =构建任务。 
 ant.echo（'build'）
} 
  

p>

 任务构建{
 description =构建任务。 
 ant.echo（'build'）
} 
  

我注意到类型B，当输入 gradle -t 时，任务内的代码似乎被执行，即使列出所有可用的任务，ant也会回应'build'。该描述实际上也以类型B显示。但是，对于类型A，列出可用任务时不执行代码，并且执行 gradle -t 时不显示该描述。 。这些文档似乎没有涉及这两种语法之间的差异（我发现），只是您可以以任何方式定义任务。

解决方案方案

第一个语法定义了一个任务，并提供了一些任务执行时要执行的代码。第二种语法定义了一个任务，并提供了一些代码以便立即执行以配置任务。例如：

 任务构建<< {println'执行构建任务时执行'} 
任务构建{println'执行构建脚本时执行'} 
  

实际上，第一个语法相当于：

 任务构建{doLast {println '执行构建任务时执行'}} 
  

因此，在上例中，对于语法A描述不会在gradle -t中显示，因为设置描述的代码在执行任务之前不会执行，当您运行gradle -t时不会发生。

对于语法B，执行ant.echo（）的代码针对gradle的每次调用运行，包括gradle -t

提供要执行的操作和

 任务构建（描述：'一些描述'）<< {一些代码} 
任务build {description ='一些描述'; doLast {一些代码}} 
  

A)

task build << {  
  description = "Build task."  
  ant.echo('build')  
}

B)

task build {  
  description = "Build task."  
  ant.echo('build')  
}

I notice that with type B, the code within the task seems to be executed when typing gradle -t - ant echoes out 'build' even when just listing all the various available tasks. The description is also actually displayed with type B. However, with type A no code is executed when listing out the available tasks, and the description is not displayed when executing gradle -t. The docs don't seem to go into the difference between these two syntaxes (that I've found), only that you can define a task either way.

解决方案

The first syntax defines a task, and provides some code to be executed when the task executes. The second syntax defines a task, and provides some code to be executed straight away to configure the task. For example:

task build << { println 'this executes when build task is executed' }
task build { println 'this executes when the build script is executed' }

In fact, the first syntax is equivalent to:

task build { doLast { println 'this executes when build task is executed' } }

So, in your example above, for syntax A the description does not show up in gradle -t because the code which sets the description is not executed until the task executed, which does not happen when you run gradle -t.

For syntax B the code that does the ant.echo() is run for every invocation of gradle, including gradle -t

To provide both an action to execute and a description for the task you can do either of:

task build(description: 'some description') << { some code }
task build { description = 'some description'; doLast { some code } }

这篇关于gradle中这些任务定义语法之间的区别是什么？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！