我有一个关于使用目标C解析字符串的快速问题。目前，我有一个输出* A_1_2_3_4_~的格式。该字符串具有消息开头（*），标题（A），值（1）和消息结束（〜）。我已经为arduino编写了这段代码，但似乎无法让它在目标c中正常工作。该函数的作用是将每个值分开并对其进行分类。非常高效和坚固。如果我发送* A_1_1_1_~，则会识别出A代表的是某个值，值为1,1,1。无论如何，这里代码为：
//protocol for parsing
-(void)protocol:(NSString*)input type:(Boolean*)comType
{
Byte place = 0, index, ID, average, setGet; //any value < 256
int probeType, tempType;
char Header;
NSString *output; //used for parsing
double probeValue, tempValue;
// if(comType){}
// //wire = ""; //reset wire
// else
// analog.text = @"";//serial = ""; //reset serial
//if error in message example: A_1_1_A_1_A_A_A*A_1_1_8.27_1_15.67_3_~
//use '*' as start of message character and grab from *A_1_1_8.27_1_15.67_3_~
probeType = input.length; //get length of string
index = [input rangeOfString:@"*" options:NSBackwardsSearch].location; //index = input.lastIndexOf("*"); //index contains start of message
if(index < 0) //not available or incorrect format
return;
input = [input substringFromIndex:index]; //remove incorrect stuff
average = [input rangeOfString:@"~"].location; //input.indexOf("~", index); //grab end of message
input = [input substringWithRange:NSMakeRange(index+1, average+index)]; //input = input.substring(index + 1, average + 1); //grab valid string only, lower bandwidth
// [self alert: input];
for(Byte i = 0; i < 8; i++) //limit the message length as well
{
// index = [input rangeOfString:@"_"].location; //grab location of
index = [input rangeOfString:@"_" options:Nil range:NSMakeRange(place, input.length)].location;//index = input.indexOf("_", place); //gets first update
// [self alert:index];
if(index < 0 || [input characterAtIndex:index+1] == '~')//input.substring(place, index + 1) == "~") //no '_' found or EOM
break; //two birds one stone
output = [input substringWithRange:NSMakeRange(place, index)];//output = input.substring(place, index); //grab in between
//input = [input stringByReplacingCharactersInRange:NSMakeRange(0, index) withString:@""];//remove already read
switch(i)
{
case 0: //header
Header = [output characterAtIndex:0]; //fast conversion from String to char
break;
case 1: //ID
ID = [output intValue]; //toInt() returns long...not int; perfect for conductivity
break;
case 2: //Probe Type
probeType = [output intValue];
break;
case 3: //Probe Value
probeValue = [output doubleValue];
break;
case 4: //Temperature Type
tempType = [output intValue];
break;
case 5: //Temperature Value
tempValue = [output doubleValue];
break;
case 6: //Average
average = [output intValue];
break;
case 7:
setGet = [output intValue];
break;
}
place = index + 1;
[self alert: output];
}
}
答案 0 :(得分：1)
目前尚不清楚所有参数对于格式的外观是什么，但我会这样做以从字符串中提取数字。就像你的问题一样，我在字符串中查找第一个“*”，从末尾向后搜索。
- (void)viewDidLoad {
[super viewDidLoad];
NSCharacterSet *nonNumbers = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789."] invertedSet];
NSString *s = @"A_1_1_A_1_A_A_A*A_1_1_8.27_1_15.67_3_~"; // test string
NSInteger locationOfAsterisk = [s rangeOfString:@"*" options:NSBackwardsSearch].location;
if (locationOfAsterisk != NSNotFound) {
NSString *validString = [s substringFromIndex:locationOfAsterisk + 1];
NSMutableArray *parsedArray = [[s componentsSeparatedByString:@"_"] mutableCopy];
NSIndexSet *indxs = [parsedArray indexesOfObjectsPassingTest:^BOOL(NSString *obj, NSUInteger idx, BOOL *stop) {
return [obj rangeOfCharacterFromSet:nonNumbers].location != NSNotFound ;
}];
[parsedArray removeObjectsAtIndexes:indxs];
[parsedArray insertObject:[validString substringToIndex:1] atIndex:0];
NSLog(@"%@",parsedArray);
}else{
NSLog(@"Not a valid format");
}
}
这将返回一个数组，第一个元素是星号后面的字母，后跟所有数字，直到代字号。
答案 1 :(得分：0)
//protocol for parsing
-(void)protocol:(NSString*)inputString type:(Boolean*)comType
{
int probeType, tempType, index, ID, average, setGet;
NSMutableString *Header;
// NSString *output; //used for parsing
double probeValue, tempValue;
//if error in message example: A_1_1_A_1_A_A_A*A_1_1_8.27_1_15.67_3_~
//use '*' as start of message character and grab from *A_1_1_8.27_1_15.67_3_~
probeType = inputString.length; //steal probeType for now, probeType contains length of string
index = [inputString rangeOfString:@"*" options:NSBackwardsSearch].location; //index contains SoM, index
if(index < 0) //not available
return;
inputString = [inputString substringFromIndex:index]; //remove incorrect stuff before SoM
average = [inputString rangeOfString:@"~"].location; //grab end of message
inputString = [inputString substringWithRange:NSMakeRange(index+1, average)]; //grab valid string from SoM with length
inputString = [inputString stringByReplacingOccurrencesOfString:@"*" withString:@""]; //need to remove *
inputString = [inputString stringByReplacingOccurrencesOfString:@"~" withString:@""]; //need to remove ~
NSMutableArray *arrayOfNumbers = [[inputString componentsSeparatedByString:@"_"] mutableCopy]; //
int objects = [arrayOfNumbers count]; //no need for ~ sign
for(int i = 0; i < objects; i++) //limit the message length as well
{
switch(i)
{
case 0: //header
Header = [arrayOfNumbers objectAtIndex:i]; //[output characterAtIndex:0]; //fast conversion from String to char
break;
case 1: //ID
ID = [[arrayOfNumbers objectAtIndex:i] intValue]; //[output intValue]; //toInt() returns long...not int; perfect for conductivity
break;
case 2: //Probe Type
probeType = [[arrayOfNumbers objectAtIndex:i] intValue];
break;
case 3: //Probe Value
probeValue = [[arrayOfNumbers objectAtIndex:i] doubleValue];
break;
case 4: //Temperature Type
tempType = [[arrayOfNumbers objectAtIndex:i] intValue];
break;
case 5: //Temperature Value
tempValue = [[arrayOfNumbers objectAtIndex:i] doubleValue];
break;
case 6: //Average
average = [[arrayOfNumbers objectAtIndex:i] intValue];
break;
case 7:
setGet = [[arrayOfNumbers objectAtIndex:i] intValue];
break;
}
[self alert: [arrayOfNumbers objectAtIndex:i]];
}
}