前言：开发flutter原生插件时可能需要加载图片；图片资源放在本地插件中感觉不是很好，可以放在flutter 层代码里面，在原生插件中加载flutter里面的图片。

实现代码如下FFileManager.h 文件

#import <Flutter/Flutter.h>

NS_ASSUME_NONNULL_BEGIN

@interface FFileManager : NSObject

/// registar
@property (nonatomic, strong) NSObject<FlutterPluginRegistrar> *registar;

/// FFileManagerCenter
+ (instancetype)defaultCenter;

/// 获取flutter端图片资源路径
- (nullable NSString *)pathForFlutterImageName:(nullable NSString *)imageName;

/// 获取flutter端文件资源路径
- (nullable NSString *)pathForFlutterFileName:(nullable NSString *)fileName;


@end

FFileManager.m文件

#import "FFileManager.h"

@implementation FFileManager

static FFileManager *_instance = nil;
+ (instancetype)defaultCenter {
    return [[FFileManager alloc] init];
}

+ (instancetype)allocWithZone:(struct _NSZone *)zone {
     @synchronized(self) { // 同步
        if (!_instance) {
            _instance = [super allocWithZone:zone];
        }
    }
    return _instance;
}
 
- (instancetype)copyWithZone:(struct _NSZone *)zone {
    return _instance;
}

- (instancetype)mutableCopyWithZone:(nullable NSZone *)zone {
    return _instance;
}

/// 获取flutter端图片资源路径
- (nullable NSString *)pathForFlutterImageName:(nullable NSString *)imageName {
    if (!_registar || !imageName) return nil;
    return [[NSBundle mainBundle] pathForResource:[_registar lookupKeyForAsset:imageName] ofType:nil];
}
/// 获取flutter端文件资源路径
- (nullable NSString *)pathForFlutterFileName:(nullable NSString *)fileName {
    if (!_registar || !fileName) return nil;
    return [[NSBundle mainBundle] pathForResource:[_registar lookupKeyForAsset:fileName] ofType:nil];
}

@end

使用方法：images/map/title_icon.png 为flutter 图片路径

[UIImage imageWithContentsOfFile:[[FFileManager defaultCenter] pathForFlutterImageName:@"images/map/title_icon.png"]]