# fromAssetImage method

Future <BitmapDescriptor> fromAssetImage (

1. ImageConfiguration configuration,
2. String assetName,
3. {AssetBundle bundle,
4. String package,
5. bool mipmaps: true}

)

从资源图像创建BitmapDescriptor。

Flutter中的assert的资产图像按以下方式存储： https://flutter.dev/docs/development/ui/assets and images声明-分辨率感知图像资源 该方法考虑了各种资产解决方案 并根据dpi将图像缩放到正确的分辨率。 将`mipmaps1设置为false可加载图像的精确dpi版本，默认情况下，`mipmap`为true。

## Implementation

    static Future<BitmapDescriptor> fromAssetImage(
      ImageConfiguration configuration,
      String assetName, {
      AssetBundle bundle,
      String package,
      bool mipmaps = true,
    }) async {
      if (!mipmaps && configuration.devicePixelRatio != null) {
        return BitmapDescriptor._(<dynamic>[
          'fromAssetImage',
          assetName,
          configuration.devicePixelRatio,
        ]);
      }
      final AssetImage assetImage =
          AssetImage(assetName, package: package, bundle: bundle);
      final AssetBundleImageKey assetBundleImageKey =
          await assetImage.obtainKey(configuration);
      return BitmapDescriptor._(<dynamic>[
        'fromAssetImage',
        assetBundleImageKey.name,
        assetBundleImageKey.scale,
        if (kIsWeb && configuration?.size != null)
          [
            configuration.size.width,
            configuration.size.height,
          ],
      ]);
    }