如何高亮图片中的“手机”字样?
已更新
我想在页面上搜索文本,如果找到,文本应该按照我在附图中显示的方式突出显示。
最佳答案
输出
这Regular Expressions tutorial详细介绍了如何在 UITextview
上使用正则表达式搜索所需的文本以及如何突出显示它。
要使用的基本代码:
- (void)viewDidLoad
{
[super viewDidLoad];
[self searchData];
}
1) 以下代码从数据中搜索所需的模式,即 TextView:
- (void) searchData
{
NSError *error = NULL;
NSString *pattern = @"Hello"; // pattern to search thee data either regular expression or word.
NSString *string = self.textView.text;
NSRange range = NSMakeRange(0, string.length);
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *matches = [regex matchesInString:string options:NSMatchingProgress ran ge:range];
[self highlightMatches:matches];
}
2)这里我们使用CALayer和label高亮正则表达式匹配结果中得到的匹配:
- (void)highlightMatches:(NSArray *)matches
{
__block NSMutableAttributedString *mutableAttributedString = self.textView.attributedText.mutableCopy;
[matches enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop)
{
if ([obj isKindOfClass:[NSTextCheckingResult class]])
{
NSTextCheckingResult *match = (NSTextCheckingResult *)obj;
CGRect rect = [self frameOfTextRange:match.range inTextView:self.textView];
/** Shadow */
CALayer *shadowLayer = [CALayer new];
shadowLayer.frame = CGRectMake(rect.origin.x, rect.origin.y-4, rect.size.width, rect.size.height);
shadowLayer.cornerRadius = 5;
shadowLayer.backgroundColor = [UIColor yellowColor].CGColor;
shadowLayer.shadowColor = [UIColor blackColor].CGColor;
shadowLayer.shadowOpacity = 0.6;
shadowLayer.shadowOffset = CGSizeMake(1,1);
shadowLayer.shadowRadius = 3;
/** Label */
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(rect.origin.x, rect.origin.y-4, rect.size.width, rect.size.height)];
lbl.font = [UIFont fontWithName:@"Helvetica" size:12];
lbl.textColor = [UIColor blackColor];
[lbl setText:[[mutableAttributedString attributedSubstringFromRange:match.range] string]];
lbl.backgroundColor = [UIColor clearColor];
lbl.textAlignment = NSTextAlignmentCenter;
lbl.layer.cornerRadius = 10;
/** Add Label and layer*/
[self.view.layer addSublayer:shadowLayer];
[self.view addSubview:lbl];
}
}];
}
用于获取textView中匹配文本的frame的函数:
- (CGRect)frameOfTextRange:(NSRange)range inTextView:(UITextView *)textView
{
UITextPosition *beginning = textView.beginningOfDocument; //Error=: request for member 'beginningOfDocument' in something not a structure or union
UITextPosition *start = [textView positionFromPosition:beginning offset:range.location];
UITextPosition *end = [textView positionFromPosition:start offset:range.length];
UITextRange *textRange = [textView textRangeFromPosition:start toPosition:end];
CGRect rect = [textView firstRectForRange:textRange]; //Error: Invalid Intializer
return [textView convertRect:rect fromView:textView.textInputView]; // Error: request for member 'textInputView' in something not a structure or union
}
关于iphone - 如何突出显示图像中的文字?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16828425/