概述
我们在使用Android Studio创建Activity、Fragment等等的时候，都会使用Android Studio提供的模板来简化我们创建的，使用模板时，我们只要做简单的配置，Android就能为我们生成相应的代码，所以使用模板可以提高开发的效率，接下来我们将学习如何去自定义一个符合自己项目框架的模板。
介绍
Android Studio模板的安装路径：
<Android Studio安装目录>/plugins/android/lib/templates
as_template_dir.png
as_template.png
模板文件结构
Android Studio中已有的Empty Activity模板：
empty_activity_template.png
模板组成结构：
- template.xml：定义模板参数
- globals.xml.ftl：定义全局变量
- recipe.xml.ftl：配置要引用的模板路径和生成的文件的路径
- root文件：存放模板文件和资源文件
- 效果缩略图
模板变量处理流程：
template_variable_dataflow.png
template.xml
<?xml version="1.0"?>
<template
format="5"
revision="5"
name="Empty Activity"
minApi="9"
minBuildApi="14"
description="Creates a new empty activity">
<category value="Activity" />
<formfactor value="Mobile" />
<parameter
id="activityClass"
name="Activity Name"
type="string"
constraints="class|unique|nonempty"
suggest="${layoutToActivity(layoutName)}"
default="MainActivity"
help="The name of the activity class to create" />
<parameter
id="generateLayout"
name="Generate Layout File"
type="boolean"
default="true"
help="If true, a layout file will be generated" />
<parameter
id="layoutName"
name="Layout Name"
type="string"
constraints="layout|unique|nonempty"
suggest="${activityToLayout(activityClass)}"
default="activity_main"
visibility="generateLayout"
help="The name of the layout to create for the activity" />
<parameter
id="isLauncher"
name="Launcher Activity"
type="boolean"
default="false"
help="If true, this activity will have a CATEGORY_LAUNCHER intent filter, making it visible in the launcher" />
<parameter
id="backwardsCompatibility"
name="Backwards Compatibility (AppCompat)"
type="boolean"
default="true"
help="If false, this activity base class will be Activity instead of AppCompatActivity" />
<parameter
id="packageName"
name="Package name"
type="string"
constraints="package"
default="com.mycompany.myapp" />
<!-- 128x128 thumbnails relative to template.xml -->
<thumbs>
<!-- default thumbnail is required -->
<thumb>template_blank_activity.png</thumb>
</thumbs>
<globals file="globals.xml.ftl" />
<execute file="recipe.xml.ftl" />
</template>
template.png
说明：
-
<template>中的name对应新建Activity时显示的名字 -
<category>对应New的类别为Activity -
<parameter>对应界面上蓝色框的一个项，- id：唯一表示，最终通过该属性值，获取用户界面上的输入值
- name：界面上Label提示语
- type：输入值类型
- constraints：值约束
- suggest：建议值，比如填写ActivityName的时候，会给出LayoutName的建议值
- help：底部显示的提示语
globals.xml.ftl
<globals>
<global id="hasNoActionBar" type="boolean" value="false" />
<global id="parentActivityClass" value="" />
<global id="simpleLayoutName" value="${layoutName}" />
<global id="excludeMenu" type="boolean" value="true" />
<global id="generateActivityTitle" type="boolean" value="false" />
<#include "../common/common_globals.xml.ftl" />
</globals>
这个文件用于定义一些全局变量。
说明：
<global>：表示一个全局变量
- id：变量名
- type：变量类型
- value：默认值
访问变量：${变量id}
recipe.xml.ftl
<#import "root://activities/common/kotlin_macros.ftl" as kt>
<recipe>
<#include "../common/recipe_manifest.xml.ftl" />
<@kt.addAllKotlinDependencies />
<#if generateLayout>
<#include "../common/recipe_simple.xml.ftl" />
<open file="${escapeXmlAttribute(resOut)}/layout/${layoutName}.xml" />
</#if>
<instantiate from="root/src/app_package/SimpleActivity.${ktOrJavaExt}.ftl"
to="${escapeXmlAttribute(srcOut)}/${activityClass}.${ktOrJavaExt}" />
<open file="${escapeXmlAttribute(srcOut)}/${activityClass}.${ktOrJavaExt}" />
</recipe>
该文件用于定义如何生成代码和文件。
说明：
-
<#include>：导入另一个ftl文件 -
<open>：在代码生成后打开指定文件，例如，当我们创建一个Activity后，AS会自动打开Activity及布局文件。 -
<instantiate>：将.ftl文件转成.java或.kt文件。 -
<copy>：用于从root文件夹中复制文件到目标目录。 -
<merge>：用于合并文件，如将模板的strings.xml合并到我们项目中的strings.xml
Freemarker语法
AS 中模板的定义使用的是Freemarker的语法。
语法
${变量名}：访问变量值<#if 变量名>：条件判断<#include "xx.ftl">：引入其他模板文件
实例：EmptyActivity\root\src\app_package\SimpleActivity.java.ftl
package ${packageName};
import ${superClassFqcn};
import android.os.Bundle;
<#if (includeCppSupport!false) && generateLayout>
import android.widget.TextView;
</#if>
public class ${activityClass} extends ${superClass} {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
<#if generateLayout>
setContentView(R.layout.${layoutName});
<#include "../../../../common/jni_code_usage.java.ftl">
<#elseif includeCppSupport!false>
// Example of a call to a native method
android.util.Log.d("${activityClass}", stringFromJNI());
</#if>
}
<#include "../../../../common/jni_code_snippet.java.ftl">
}
从模板到代码的流程：
code_generation_process.png
自定义MVP模板
在Google给出的MVP Sample中，每创建一个页面，需要创建：
XxActivity、XxFragment、XxContract、XxPresenter四个文件，步骤繁琐，且AS目前没有提供相应的模板，所以接下来将自定义一个MVP的模板，来简化这些繁琐的操作。
template.xml
<?xml version="1.0"?>
<template
format="5"
revision="5"
name="Page"
minApi="9"
minBuildApi="14"
description="Creates a new MVP page">
<category value="MVP" />
<formfactor value="Mobile" />
<parameter
id="activityClass"
name="Activity Name"
type="string"
constraints="class|unique|nonempty"
suggest="${layoutToActivity(activityLayout)}"
default="MainActivity"
help="The name of the activity class to create" />
<parameter
id="activityLayout"
name="Activity Layout Name"
type="string"
constraints="layout|unique|nonempty"
suggest="${activityToLayout(activityClass)}"
default="activity_main"
help="The name of the layout to create for the activity" />
<parameter
id="fragmentClass"
name="Fragment Name"
type="string"
constraints="class|unique|nonempty"
suggest="${underscoreToCamelCase(classToResource(activityClass))}Fragment"
default="MainFragment"
help="The name of the fragment class to create" />
<parameter
id="fragmentLayout"
name="Fragment Layout Name"
type="string"
constraints="layout|unique|nonempty"
suggest="fragment_${classToResource(fragmentClass)}"
default="fragment_main"
help="The name of the layout to create for the fragment" />
<parameter
id="contractClass"
name="Contract Name"
type="string"
constraints="class|unique|nonempty"
suggest="${underscoreToCamelCase(classToResource(fragmentClass))}Contract"
default="MainViewModel"
help="The name of the contract class to create" />
<parameter
id="presenterClass"
name="Presenter Name"
type="string"
constraints="class|unique|nonempty"
suggest="${underscoreToCamelCase(classToResource(fragmentClass))}Presenter"
default="MainViewModel"
help="The name of the presenter class to create" />
<parameter
id="isLauncher"
name="Launcher Activity"
type="boolean"
default="false"
help="If true, this activity will have a CATEGORY_LAUNCHER intent filter, making it visible in the launcher" />
<parameter
id="packageName"
name="Package name"
type="string"
constraints="package"
default="com.mycompany.myapp" />
<parameter
id="pagePackage"
name="Page package path"
type="string"
constraints="package"
suggest="ui.${classToResource(fragmentClass)?replace('_', '')}"
default="ui.main"
help="The package path for the page." />
<!-- 128x128 thumbnails relative to template.xml -->
<thumbs>
<!-- default thumbnail is required -->
<thumb>template_blank_activity.png</thumb>
</thumbs>
<globals file="globals.xml.ftl" />
<execute file="recipe.xml.ftl" />
</template>
globals.xml.ftl
<?xml version="1.0"?>
<globals>
<global id="hasNoActionBar" type="boolean" value="false" />
<global id="parentActivityClass" value="" />
<global id="simpleLayoutName" value="${activityLayout}" />
<global id="excludeMenu" type="boolean" value="true" />
<global id="generateActivityTitle" type="boolean" value="false" />
<#include "../../activities/common/common_globals.xml.ftl" />
</globals>
recipe.xml.ftl
<?xml version="1.0"?>
<recipe>
<#-- 生成mainfest配置 -->
<merge from="root/AndroidManifest.xml.ftl"
to="${escapeXmlAttribute(manifestOut)}/AndroidManifest.xml" />
<#-- 生成布局文件 -->
<instantiate from="root/res/layout/activity.xml.ftl"
to="${escapeXmlAttribute(resOut)}/layout/${escapeXmlAttribute(activityLayout)}.xml" />
<instantiate from="root/res/layout/fragment.xml.ftl"
to="${escapeXmlAttribute(resOut)}/layout/${escapeXmlAttribute(fragmentLayout)}.xml" />
<#-- 生成.java文件 -->
<instantiate from="root/src/app_package/Activity.${ktOrJavaExt}.ftl"
to="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${activityClass}.${ktOrJavaExt}" />
<instantiate from="root/src/app_package/Fragment.${ktOrJavaExt}.ftl"
to="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${fragmentClass}.${ktOrJavaExt}" />
<instantiate from="root/src/app_package/Contract.${ktOrJavaExt}.ftl"
to="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${contractClass}.${ktOrJavaExt}" />
<instantiate from="root/src/app_package/Presenter.${ktOrJavaExt}.ftl"
to="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${presenterClass}.${ktOrJavaExt}" />
<#-- 打开文件.java文件 -->
<open file="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${activityClass}.${ktOrJavaExt}" />
<open file="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${fragmentClass}.${ktOrJavaExt}" />
<open file="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${contractClass}.${ktOrJavaExt}" />
<open file="${escapeXmlAttribute(srcOut)}/${pagePackage?replace('.', '/')}/${presenterClass}.${ktOrJavaExt}" />
<#-- 打开布局文件 -->
<open file="${escapeXmlAttribute(resOut)}/layout/${escapeXmlAttribute(activityLayout)}.xml" />
<open file="${escapeXmlAttribute(resOut)}/layout/${escapeXmlAttribute(fragmentLayout)}.xml" />
</recipe>
Activity.java.ftl
package ${packageName}.${pagePackage};
import ${superClassFqcn};
import android.os.Bundle;
import com.github.xch168.mvp.util.ActivityUtil;
import ${packageName}.R;
public class ${activityClass} extends ${superClass} {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.${activityLayout});
${fragmentClass} fragment = (${fragmentClass}) getSupportFragmentManager().findFragmentById(R.id.contentFrame);
if (fragment == null) {
fragment = ${fragmentClass}.newInstance();
ActivityUtil.addFragmentToActivity(getSupportFragmentManager(), fragment, R.id.contentFrame);
}
new ${presenterClass}(fragment);
}
}
Fragment.java.ftl
package ${packageName}.${pagePackage};
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import ${packageName}.R;
public class ${fragmentClass} extends Fragment implements ${contractClass}.View {
private ${contractClass}.Presenter mPresenter;
public static ${fragmentClass} newInstance() {
Bundle arguments = new Bundle();
arguments.putString("", "");
${fragmentClass} fragment = new ${fragmentClass}();
fragment.setArguments(arguments);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.${fragmentLayout}, container, false);
return root;
}
@Override
public void onResume() {
super.onResume();
mPresenter.start();
}
@Override
public void setPresenter(@NonNull ${contractClass}.Presenter presenter) {
mPresenter = presenter;
}
}
Contract.java.ftl
package ${packageName}.${pagePackage};
import com.github.xch168.mvp.ui.BasePresenter;
import com.github.xch168.mvp.ui.BaseView;
public interface ${contractClass} {
interface View extends BaseView<Presenter> {
}
interface Presenter extends BasePresenter {
}
}
Presenter.java.ftl
package ${packageName}.${pagePackage};
public class ${presenterClass} implements ${contractClass}.Presenter {
private final ${contractClass}.View mView;
public ${presenterClass}(${contractClass}.View view) {
mView = view;
mView.setPresenter(this);
}
@Override
public void start() {
}
}
AndroidManifest.xml.ftl
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="${packageName}">
<application>
<activity android:name="${packageName}.${pagePackage}.${activityClass}"
<#if generateActivityTitle!true>
<#if isNewProject>
android:label="@string/app_name"
<#else>
android:label="@string/title_${activityToLayout(activityClass)}"
</#if>
</#if>
<#if hasNoActionBar>
android:theme="@style/${themeNameNoActionBar}"
<#elseif (requireTheme!false) && !hasApplicationTheme && appCompat>
android:theme="@style/${themeName}"
</#if>
<#if buildApi gte 16 && parentActivityClass != "">
android:parentActivityName="${parentActivityClass}"
</#if>>
<#if parentActivityClass != "">
<meta-data android:name="android.support.PARENT_ACTIVITY"
android:value="${parentActivityClass}" />
</#if>
</activity>
</application>
</manifest>
使用MVP模板
将模板文件复制到
<Android Studio安装目录>/plugins/android/lib/templates/{userName}/MVP目录下，然后重启Android Studio。
Step1：新建一个MVP页面
use_mvp_templage.jpg
Step2：配置参数
fill_mvp_template.png
Step3：点击Finish，将自动生成相关代码及资源文件
gen_mvp_code.png
