我尝试将Objective-C框架用于我的项目,并在将Objective-C代码转换为Swift时遇到一些问题。将Objective-C代码转换为Swift时EXC_BAD_ACCESS
其中的API:
- (void)ioFrameChannel:(PTChannel*)channel didReceiveFrameOfType:(uint32_t)type tag:(uint32_t)tag payload:(PTData*)payload
payload.data是这样的结构:
typedef struct _PTExampleTextFrame {
uint32_t length;
uint8_t utftext[0];
} PTExampleTextFrame;
我想PTExampleTextFrame.utftext
这是一个消息从框架发送
所以我创建了一个本地的struct
:
struct CPTExampleTextFrame {
var length: UInt32
var utf8text: UnsafePointer<UInt8>
}
而且这样写:
var textFrame = UnsafePointer<CPTExampleTextFrame>(payload.data).memory
textFrame.length = CFSwapInt32(textFrame.length)
print(textFrame.length) // textFrame.length is correct!
let message = NSString(bytes: textFrame.utf8text, length: Int(textFrame.length), encoding: NSUTF8StringEncoding) // error
print(message)
But I get an error: EXC_BAD_ACCESS(code=1,address=0x31)
谁能告诉我是什么问题?
而且也是我给你的框架的例子是在Objective-C:
- (void)ioFrameChannel:(PTChannel*)channel didReceiveFrameOfType:(uint32_t)type tag:(uint32_t)tag payload:(PTData*)payload {
if (type == PTExampleFrameTypeTextMessage) {
PTExampleTextFrame *textFrame = (PTExampleTextFrame*)payload.data;
textFrame->length = ntohl(textFrame->length);
NSString *message = [[NSString alloc] initWithBytes:textFrame->utf8text length:textFrame->length encoding:NSUTF8StringEncoding];
[self appendOutputMessage:[NSString stringWithFormat:@"[%@]: %@", channel.userInfo, message]];
} else if (type == PTExampleFrameTypePing && peerChannel_) {
[peerChannel_ sendFrameOfType:PTExampleFrameTypePong tag:tag withPayload:nil callback:nil];
}
}
感谢您的咨询!最后,我使用了Objective-C方法来构建我需要的信息,并且只需要我一分钟......所以,我认为,在某些情况下,Swift并不总是Swift项目中的最佳选择。 – Duelsol