如何突出显示图像中的文字“手机”？
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我想在页面上搜索文本，如果找到，文本应该以我在附图中显示的方式突出显示。
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输出
这个正则表达式教程详细介绍了如何使用正则表达式搜索所需的文本UITextview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突出显示从正则表达式匹配的结果中得到的匹配：
- (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
}
于 2013-05-30T05:30:39.500 回答
5
使用NSMutableAttributedString它可能对您有用。
NSString *myString = @"Hello";
NSMutableAttributedString *aString = [[NSMutableAttributedString alloc] initWithString:myString];
NSRange theRange = NSMakeRange(0,[aString length]);
//这里我们为文本设置前景色和背景色以突出显示它。
[aString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"MyriadPro-Bold" size:17.5f] range:theRange];
[aString addAttribute:NSForegroundColorAttributeName value:[UIColor purpleColor] range:theRange];
[aString addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:theRange];
//您可以根据要突出显示的文本部分来更改范围。
于 2013-05-30T05:42:37.723 回答
2
为此，您必须使用core Text& 来突出显示您必须在方法中绘制文本，drawRect即将背景颜色更改为黄色并增加文本的字体大小
于 2013-05-30T05:20:04.913 回答
2
于 2013-06-12T02:49:52.770 回答