Question

我需要将数据发送到串口。要发送的内容的定义是：

Chr$(2) = Clear buffer
Chr$(48)&Chr(57) = Any number between 0 to 359

输入2090的尝试失败

int i, c;
char j;
NSString *tmpStr = [self.sendTextField stringValue];
NSString *tmpVal;
for (i = 0 ; i < [tmpStr length]; i++)
{
  NSLog(@"Iteration: %d", i);
  tmpVal = [tmpStr substringWithRange:NSMakeRange(i, 1)];
  c = [tmpVal intValue];
  j = (char)c;
  tmpVal = [NSString stringWithFormat:@"%c", j];
  NSData *dataToSend = [tmpVal.value dataUsingEncoding:NSUTF8StringEncoding]; **<Error here**
  [self.serialPort sendData:dataToSend];
}

我不知道如何纠正控制台报告的错误。

2013-03-08 10:38:12.430 ORSSerialPortCocoaDemo[40656:303] Iteration: 0
2013-03-08 10:38:38.819 ORSSerialPortCocoaDemo[40656:303] -[__NSCFString value]: unrecognized selector sent to instance 0x1001626a0
2013-03-08 10:38:38.819 ORSSerialPortCocoaDemo[40656:303] -[__NSCFString value]:    unrecognized selector sent to instance 0x1001626a0
2013-03-08 10:38:38.821 ORSSerialPortCocoaDemo[40656:303] (
0   CoreFoundation                      0x00007fff858180a6 __exceptionPreprocess + 198
1   libobjc.A.dylib                     0x00007fff835b03f0 objc_exception_throw + 43
2   CoreFoundation                      0x00007fff858ae6ea -[NSObject(NSObject) doesNotRecognizeSelector:] + 186
3   CoreFoundation                      0x00007fff858065ce ___forwarding___ + 414
4   CoreFoundation                      0x00007fff858063b8 _CF_forwarding_prep_0 + 232
5   ORSSerialPortCocoaDemo              0x0000000100008e81 -[ORSSerialPortDemoController send:] + 465
6   AppKit                              0x00007fff868d6a59 -[NSApplication sendAction:to:from:] + 342
7   AppKit                              0x00007fff868d68b7 -[NSControl sendAction:to:] + 85
8   AppKit                              0x00007fff868d67eb -[NSCell _sendActionFrom:] + 138
9   AppKit                              0x00007fff868d4cd3 -[NSCell trackMouse:inRect:ofView:untilMouseUp:] + 1855
10  AppKit                              0x00007fff868d4521 -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:] + 504
11  AppKit                              0x00007fff868d3c9c -[NSControl mouseDown:] + 820
12  AppKit                              0x00007fff868cb60e -[NSWindow sendEvent:] + 6853
13  AppKit                              0x00007fff868c7744 -[NSApplication sendEvent:] + 5761
14  AppKit                              0x00007fff867dd2fa -[NSApplication run] + 636
15  AppKit                              0x00007fff86781cb6 NSApplicationMain + 869
16  ORSSerialPortCocoaDemo              0x0000000100001d62 main + 34
17  ORSSerialPortCocoaDemo

Answer 1

删除对value方法的调用：

NSData *dataToSend = [tmpVal dataUsingEncoding:NSUTF8StringEncoding];

创建数据对象

1 个答案: