Android 开发问题：项目同时引入了两个包含相同类文件的库（AndroidX 库、旧版本支持库），导致了重复类错误

implementation 'com.pes.materialcolorpicker:library:1.2.5'

ColorPicker colorPicker = new ColorPicker(this);

colorPicker.setColor(Color.RED);

colorPicker.setCallback(color -> {
    colorPicker.dismiss();
    Log.i(TAG, "color = " + color);
});

colorPicker.show();

• 在 Android 开发中，引入 ColorPicker 后，构建项目时，出现如下错误信息

  Duplicate class android.support.v4.app.INotificationSideChannel found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)
  Duplicate class android.support.v4.app.INotificationSideChannelStub found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1) Duplicate class android.support.v4.app.INotificationSideChannelStubProxy found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1) Duplicate class android.support.v4.os.IResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1) Duplicate class android.support.v4.os.IResultReceiverStub found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)
  Duplicate class android.support.v4.os.IResultReceiverStubProxy found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)
  Duplicate class android.support.v4.os.ResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)
  Duplicate class android.support.v4.os.ResultReceiver1 found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1) Duplicate class android.support.v4.os.ResultReceiverMyResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)
  Duplicate class android.support.v4.os.ResultReceiver$MyRunnable found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-25.3.1-runtime (com.android.support:support-compat:25.3.1)

  解读

  在模块 core-1.9.0-runtime（androidx.core:core:1.9.0）
  和 support-compat-25.3.1-runtime（com.android.support:support-compat:25.3.1）
  中发现重复的类 android.support.v4.app.INotificationSideChannel

  ...

问题原因

• 项目同时引入了两个包含相同类文件的库，导致了重复类错误，冲突双方如下

1. AndroidX 库（新版本支持库）：androidx.core:core:1.9.0

2. 旧版本支持库：com.android.support:support-compat:25.3.1

处理策略

• 在 gradle.properties 文件中添加如下内容

android.useAndroidX=true
android.enableJetifier=true

1. android.useAndroidX=true：表示项目使用 AndroidX 库

2. android.enableJetifier=true：表示允许 Gradle 自动重写旧的第三方库的二进制文件，将其中的旧支持库引用转换为 AndroidX 引用