fix:优化图片上传组件，解决png图片报错问题

lib/upload_image/ossUtil.dart

@@ -37,8 +37,15 @@ class UploadOss {
     required String ossHost,
     bool? isShowLoading,
   }) async {
+    final String normalizedFileType =
+        fileType.toLowerCase() == 'jpeg' ? 'jpg' : fileType.toLowerCase();
+    final bool isVideo = normalizedFileType == 'mp4';
+    final String? imageContentType = isVideo
+        ? null
+        : (normalizedFileType == 'jpg' ? 'jpeg' : normalizedFileType);
     // 生成oss的路径和文件名我这里目前设置的是moment/20201229/test.mp4
-    String pathName = "$rootDir/${getDate()}/app-${getRandom(12)}.$fileType";
+    String pathName =
+        "$rootDir/${getDate()}/app-${getRandom(12)}.$normalizedFileType";
 
     // 请求参数的form对象
     FormData formdata = FormData.fromMap({
@@ -51,8 +58,8 @@ class UploadOss {
       'success_action_status': '200',
       'file': MultipartFile.fromFileSync(
         path,
-        contentType: fileType == 'mp4' ? null : DioMediaType("image", "jpg"),
-        filename: "${getRandom(12)}.$fileType",
+        contentType: isVideo ? null : DioMediaType("image", imageContentType!),
+        filename: "${getRandom(12)}.$normalizedFileType",
       ),
     });
     if (isShowLoading == true) {
@@ -71,13 +78,19 @@ class UploadOss {
         ossHost,
         data: formdata,
         options: Options(
-          contentType: "multipart/form-data;image/jpg",
-          headers: {'Content-Type': 'multipart/form-data;image/jpg'},
+          contentType: isVideo
+              ? "multipart/form-data"
+              : "multipart/form-data;image/$imageContentType",
+          headers: {
+            'Content-Type': isVideo
+                ? "multipart/form-data"
+                : "multipart/form-data;image/$imageContentType",
+          },
         ),
       );
       print("response ===== $response");
       EasyLoading.dismiss();
-      if(fileType == 'jpg'){
+      if (!isVideo && path.contains('compressed_images_')) {
         /// 删除临时文件
         File(path).deleteSync();
       }