Gradle中buildConfigField的使用

buildConfigField可以定义我们需要的变量，并在代码中引用。

gradle配置如下：

applicationId "com.flyscale.gradleflavor.b"  //applicationId是Gradle定义好的变量
versionName "version-b-1.0"  //versionName是Gradle定义好的变量
buildConfigField("String", "PRODUCT_NAME", "\"b\"");  //新定义String类型变量PRODUCT_NAME，值为"b"
buildConfigField("boolean", "LOG_DEBUG", "false"); //新定义boolean类型变量LOG_DEBUG,值为false

执行sync后会生成如下代码：

public final class BuildConfig {
  public static final boolean DEBUG = Boolean.parseBoolean("true");
  public static final String APPLICATION_ID = "com.flyscale.gradleflavor.b";
  public static final String BUILD_TYPE = "debug";
  public static final String FLAVOR = "productB";
  public static final int VERSION_CODE = 1;
  public static final String VERSION_NAME = "version-b-1.0";
  // Fields from product flavor: productB
  public static final boolean LOG_DEBUG = false;
  public static final String PRODUCT_NAME = "b";
}

这时我们就可以在代码中调用了：

Log.d(TAG, "APPLICATION_ID=" + BuildConfig.APPLICATION_ID);
Log.d(TAG, "LOG_DEBUG=" + BuildConfig.LOG_DEBUG);
Log.d(TAG, "PRODUCT_NAME=" + BuildConfig.PRODUCT_NAME);