能否为Android Manifest文件包名设置动态占位符？

Short answer: No, you can't use a dynamic placeholder such as ${ApplicationId} for the root package attribute in your AndroidManifest.xml. Here's why, and how to handle similar needs:

Key Background: Difference Between package (Manifest) and applicationId (Gradle) #

First, it's critical to distinguish these two often-confused values:

• The package attribute in AndroidManifest.xml is a static, compile-time required value. It defines:
  • The package namespace for generated classes like R.java
  • The default namespace for your app's components (Activities, Services, Broadcast Receivers, etc.)
  • The base path for resolving resource references in your code
• The applicationId in your app's build.gradle (or build.gradle.kts) is the unique identifier for your app on the Google Play Store and Android system. This is the value you can dynamically modify (e.g., add suffixes for build variants) without affecting your code structure.

Why You Can't Use ${ApplicationId} for the Manifest package #

The Android build system processes the Manifest early in the compilation pipeline, before resolving Gradle placeholders. It needs the static package value to generate core artifacts like R.java and validate component names. Dynamic placeholders here would break the build process entirely.

How to Achieve "Dynamic App Identification" Without Changing the Manifest package #

If you want different app IDs for different build variants (e.g., dev vs. production builds), you don't need to touch the Manifest's package attribute. Instead, modify the applicationId in your Gradle configuration:

android {
    defaultConfig {
        // Default app ID matches your Manifest's package (but they're separate!)
        applicationId "com.india.hello"
    }

    productFlavors {
        dev {
            // Add a suffix to create a unique app ID for development builds
            applicationIdSuffix ".dev"
        }
        prod {
            // Keep the default applicationId for production
        }
    }
}

This setup lets you have multiple versions of your app installed on the same device (e.g., dev and prod builds) while keeping your Manifest's package static and intact.

What You Can Use Placeholders For #

While you can't replace the root package attribute, you can use Gradle manifest placeholders for other parts of the Manifest, like component attributes or metadata:

<!-- Example: Using a placeholder for an activity's intent filter data -->
<activity android:name=".MainActivity">
    <intent-filter>
        <data android:scheme="${appScheme}" />
    </intent-filter>
</activity>

Then define the placeholder in Gradle:

android {
    defaultConfig {
        manifestPlaceholders = [appScheme: "myapp"]
    }
}

内容的提问来源于stack exchange，提问作者Yogesh Byndoor