NSString *allString=@"你家在哪里,需要我送你么";
NSString *subString=@"在哪里";
UILabel *stringLabel=[[UILabel alloc]init];
stringLabel.frame=CGRectMake(0, 100, 300, 30);
stringLabel.font=[UIFont systemFontOfSize:17];
stringLabel.backgroundColor=[UIColor blackColor];
stringLabel.text=allString;
stringLabel.textColor=[UIColor whiteColor];
[self.view addSubview:stringLabel];
NSString *allS=[allString lowercaseString];
NSString *subS=[subString lowercaseString];
NSRange range=[allS rangeOfString:subS];
if (range.location!=NSNotFound) {
NSMutableAttributedString *string=[[NSMutableAttributedString alloc]initWithString:allString];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor yellowColor] range:range];
stringLabel.attributedText=string;
}