[IOS]修复fetch 之后不能正确接解析chatset gbk的blob数据

Author: GAME\zengyanling

Libraries/Blob/RCTBlobManager.mm

@@ -261,12 +261,14 @@ - (id)handleNetworkingResponse:(NSURLResponse *)response data:(NSData *)data
   // An empty body will have nil for data, in this case we need to return
   // an empty blob as per the XMLHttpRequest spec.
   data = data ?: [NSData new];
+  NSString *encodingName = [response textEncodingName];
   return @{
     @"blobId": [self store:data],
     @"offset": @0,
     @"size": @(data.length),
     @"name": RCTNullIfNil([response suggestedFilename]),
     @"type": RCTNullIfNil([response MIMEType]),
+    @"encoding": encodingName == nil ? @"" : encodingName,
   };
 }
 

Libraries/Blob/RCTFileReaderModule.m

@@ -34,10 +34,11 @@ @implementation RCTFileReaderModule
   } else {
     NSStringEncoding stringEncoding;
 
-    if (encoding == nil) {
-      stringEncoding = NSUTF8StringEncoding;
+    NSString *encodingName = [RCTConvert NSString:blob[@"encoding"]];
+    if (!encodingName || [encodingName isKindOfClass:[NSNull class]] || !encodingName.length) {
+        stringEncoding = NSUTF8StringEncoding;
     } else {
-      stringEncoding = CFStringConvertEncodingToNSStringEncoding(CFStringConvertIANACharSetNameToEncoding((CFStringRef) encoding));
+        stringEncoding = CFStringConvertEncodingToNSStringEncoding(CFStringConvertIANACharSetNameToEncoding((CFStringRef) encodingName));
     }
 
     NSString *text = [[NSString alloc] initWithData:data encoding:stringEncoding];