我已经通过添加多个manifestPlaceholders值解决了我的问题，如下面的代码所示。

productFlavors {
        staging {
            applicationId "xxxxxxxxxxx"
            manifestPlaceholders = [ google_map_key:"xxxxxxxxxx", app_label_name:"xxxxxxx"]
            buildConfigField 'String', 'BASE_URL', '"xxxxxxxxxx"'
        }
        prod {
            applicationId "xxxxxxxxxxx"
            manifestPlaceholders = [ google_map_key:"xxxxxxxxxx", app_label_name:"xxxxxxx"]
            buildConfigField 'String', 'BASE_URL', '"xxxxxxxxxx"'
        }
    }

**EDIT：**您也可以使用resValue作为注解中建议的Emanuel Moecklin。

productFlavors {
            staging {
                applicationId "xxxxxxxxxxx"
                manifestPlaceholders = [ google_map_key:"xxxxxxxxxx", app_label_name:"xxxxxxx"]
                buildConfigField 'String', 'BASE_URL', '"xxxxxxxxxx"'
                resValue "string", "base_url", "xxxxxxxxxx"
            }
            prod {
                applicationId "xxxxxxxxxxx"
                manifestPlaceholders = [ google_map_key:"xxxxxxxxxx", app_label_name:"xxxxxxx"]
                buildConfigField 'String', 'BASE_URL', '"xxxxxxxxxx"'
                resValue "string", "base_url", "xxxxxxxxxx"
            }
        }

您可以轻松地设置/更改多个manifestPlaceholders值。您可以一次定义所有值（如您的答案中所示），也可以逐个定义。

defaultConfig {
    // initialize more values
    manifestPlaceholders = [ google_map_key:"xxxxxxxxxx", app_label_name:"xxxxxxx"]
    // or this way
    manifestPlaceholders.google_map_key = "xxxxxxxxxx"
    manifestPlaceholders.app_label_name = "xxxxxxxxxx"
}

productFlavors {
    staging {
    }
    prod {
        // use some different value for prod
        manifestPlaceholders.google_map_key = "yyyyyyyyyy"
    }
}

我已经提到了构建类型和风格

buildTypes {
    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        resValue "string", "google_maps_key", "release google map key"
    }
    debug {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        resValue "string", "google_maps_key", "debug google map key"
    }
}
productFlavors {
    alpha {
        applicationId = "com.example.alpha"
        resValue 'string', 'app_name', 'alphaapp'
        resValue "string", "maps_api_key", "XXXXXXXXXXXXXXXXXXXXX"
    }
    beta {
        applicationId = "com.example.beta"
        resValue 'string', 'app_name', 'betaapp'
        resValue "string", "maps_api_key", "XXXXXXXXXXXXXXXXXXXXXX"
    }
}

我不能在其他答案中使用建议的方法，因为Gradle似乎在最近的一个版本中将manifestPlaceholders的类型更改为瓦尔mutablemap。
这是唯一对我有效的解决方法：

manifestPlaceholders["key"] = "value0"
manifestPlaceholders["key"] = "value1"

我们可以使用以下方法设置manifestPlaceholders键值，
1.选择文件〉项目结构
1.添加环境

• 2-1.选择“风味”选项卡
• 2-2.添加flavor维度和维度名称，例如“env”
• 2-3.添加产品风味和名称产品，例如“prod”

1.添加清单占位符键

• 3-1.选择上述产品
• 3-2.在清单占位符列表中添加键

1.按下确定
build.gradle文件在按下按钮后自动更新