将__bridge之后的object-c指针类型nsoutputstream *强制转换为c指针类型cfwritestreamref异常

Question

i am working on a project that t¨sends a photo with smtp . In the beginning automatic reference counting was disabled and the project was running without problems . When i enabled automatic reference counting i got many compilation errors. One of the most common was Cast of Objective-C pointer type 'NSOutputStream*' to C pointer type CFWriteStreamRef (aka 'struct_CFWriteStream*' requires a bridged cast) at the lines

if (CFWriteStreamWriteFully(( CFWriteStreamRef)outputStream, (const uint8_t *)[ehlo  
UTF8String], [ehlo lengthOfBytesUsingEncoding:NSUTF8StringEncoding]) < 0)                       

When i write if (CFWriteStreamWriteFully((__bridge CFWriteStreamRef)outputStream, (const uint8_t *)
[ehlo UTF8String], [ehlo lengthOfBytesUsingEncoding:NSUTF8StringEncoding]) < 0)

it compiles but i get a runtime exception when i press the send button to send an email with smtp. I was wondering if you could help me with this problem. I would appreciate any help. Thank you in advance, Best regards

Answer 1

How can you be sure it's a wrong typeCast? Try to keep the ownership of [ehlo UTF8String] as long as the stream is writing, maybe that can help

const UInt8 *buffer = (const UInt8 *)[ehlo UTF8String];
if (CFWriteStreamWriteFully(( CFWriteStreamRef)outputStream, buffer, [ehlo lengthOfBytesUsingEncoding:NSUTF8StringEncoding]) < 0) 

By the way i haven't fount CFWriteStreamWriteFully() declaration anywhere. Only CFIndex

CFWriteStreamWrite (
   CFWriteStreamRef stream,
   const UInt8 *buffer,
   CFIndex bufferLength
);

Are there related? UInt8 and uint8_t are both unsigned char.