结构初始化

lib/core/build_mode.dart

@@ -0,0 +1,25 @@
+/// See: https://github.com/flutter/flutter/issues/11392
+///
+enum _BuildMode {
+  release,
+  debug,
+  profile,
+}
+
+_BuildMode _buildMode = (() {
+  if (const bool.fromEnvironment('dart.vm.product')) {
+    return _BuildMode.release;
+  }
+  var result = _BuildMode.profile;
+  assert(() {
+    result = _BuildMode.debug;
+    return true;
+  }());
+  return result;
+}());
+
+class BuildMode {
+  static bool isDebug = (_buildMode == _BuildMode.debug);
+  static bool isProfile = (_buildMode == _BuildMode.profile);
+  static bool isRelease = (_buildMode == _BuildMode.release);
+}