1.去除NSString字符串里面的特殊符号
-(NSString*)deleteSpecificSymbolForString:(NSString*)text{ //先创建NSCharacterSet，把需要去除的字符串放在里面 NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:@"@／:：；;￥「」＂、[]{}#%-*+=_\\|~＜＞$�^?'@#$%^&*()（）_+'\""]; //该方法返回的就是去除特殊符号后的字符串 NSString *trimmedString = [text stringByTrimmingCharactersInSet:set]; return trimmedString; } |
2.判断NSString字符串里面有没有汉字
-(BOOL)estimateStringContainChinese:(NSString*)text{ if(text){ for (int i=0; i<text.length; i++) { NSRange range = NSMakeRange(i,1); NSString *subString = [text substringWithRange:range]; const char *cString = [subString UTF8String]; if (strlen(cString) == 3){ //代表有汉字 return YES; } } } return NO; } |
3.判断NSString字符串里面有没有英文字母
-(BOOL)estimateStringContainEnglish:(NSString*)text{ if(text){ for (int i=0; i<text.length; i++) { NSRange range = NSMakeRange(i,1); NSString *subString = [text substringWithRange:range]; const char *cString = [subString UTF8String]; if (strlen(cString) == 1){ //代表有英文 return YES; } } } return NO; } |
4.在指定控制器里面更改状态栏文字颜色
每一个应用程序，应该都会有统一的导航栏和状态栏风格。但是有时候，也有需要在指定控制器里面修改
状态栏的风格，如：播放视频。
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault animated:YES];
}
-(void)viewWillDisappear:(BOOL)animated{
[super viewWillDisappear:animated];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent animated:YES];
}
5.点击进入搜索控制器时，自动弹出键盘，让搜索框进入编辑状态
当点击搜索时，进入搜索控制器，使用系统自带的搜索框，searchController.searchBar，进入时，自动实现如下图的效果
效果图.png
找了很多方法，下面这个是有效方法：
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self performSelector:@selector(showKeyboard) withObject:nil afterDelay:0];
}
- (void)showKeyboard {
[self.searchController.searchBar becomeFirstResponder];
}
6.修改系统自带搜索框的UI
系统自带的搜索框，使用方便快捷，但是有时候它的外观与要求不符，这时候就需要我们来对系统搜索框
进行一些修改
for (UIView* subview in [[self.searchController.searchBar.subviews lastObject] subviews]) { //相当于UITextField，输入框，可以修改背景颜色等 if ([subview isKindOfClass:NSClassFromString(@"UISearchBarTextField")]) { UITextField *textField = (UITextField*)subview; [textField setBackgroundColor:COLOR_RGB(238, 238, 238)]; } //相当于UIButton，搜索框右侧的Cancle按钮，可以修改默认文字等 if ([subview isKindOfClass:NSClassFromString(@"UINavigationButton")]) { UIButton* cancle = (UIButton*)subview; [cancle setTitle:@"取消" forState:UIControlStateNormal]; [cancle setTitleColor:COLOR_RGB(82, 184, 255) forState:UIControlStateNormal]; } //相当于UIView，搜索框的背景view，一般将它去掉，然后自己添加一层背景view if ([subview isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) { [subview removeFromSuperview]; UIView* back = [[UIView alloc]initWithFrame:self.searchController.searchBar.bounds]; back .backgroundColor = [UIColor whiteColor]; [self.searchController.searchBar insertSubview:back atIndex:0]; } } |
7.在指定控制器中隐藏导航栏
有时候，需要在指定控制器中隐藏导航栏，试过好几个方法，或多或少有些坑，下面这个是我认为比较好的：
首先让该控制器成为导航栏的代理：
self.navigationController.delegate = self;
然后，实现指定的代理方法：
-(void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated{ if ([viewController isKindOfClass:[self class]]) { [self.navigationController setNavigationBarHidden:YES animated:YES]; } //返回时，在指定控制器重新让导航栏显示 if ([viewController isKindOfClass:[ContactVC class]]) { [self.navigationController setNavigationBarHidden:NO animated:YES]; } } |
8.根据指定文本，字体，固定宽度或高度，求尺寸
// 根据指定文本,字体和最大高度计算尺寸 - (CGSize)sizeWithText:(NSString *)text font:(UIFont *)font maxHeight:(CGFloat)height { NSMutableDictionary *attrDict = [NSMutableDictionary dictionary]; attrDict[NSFontAttributeName] = font; CGSize size = [text boundingRectWithSize:CGSizeMake(MAXFLOAT, height) options:NSStringDrawingUsesLineFragmentOrigin attributes:attrDict context:nil].size; return size; } // 根据指定文本,字体和最大宽度计算尺寸 - (CGSize)sizeWithText:(NSString *)text font:(UIFont *)font maxWidth:(CGFloat)width { NSMutableDictionary *attrDict = [NSMutableDictionary dictionary]; attrDict[NSFontAttributeName] = font; CGSize size = [text boundingRectWithSize:CGSizeMake(width, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:attrDict context:nil].size; return size; } |
9.给UILabel设置行间距，字间距等富文本属性，并计算高度
//给UILabel设置行间距和字间距 -(void)setLabelSpace:(UILabel*)label withValue:(NSString*)str withFont:(UIFont*)font { NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init]; paraStyle.lineBreakMode = NSLineBreakByCharWrapping; //结尾部分的文字省略方式 paraStyle.alignment = NSTextAlignmentLeft; //文本对齐方式 paraStyle.lineSpacing = 7; //设置行间距 paraStyle.hyphenationFactor = 1.0; //连字属性 在iOS，唯一支持的值分别为0和1 paraStyle.firstLineHeadIndent = 0.0; //首行缩进 paraStyle.paragraphSpacingBefore = 0.0; //段首行空白空间 paraStyle.headIndent = 0; //整体缩进(首行除外) paraStyle.paragraphSpacing = 15; //段与段之间的间距 //设置字间距 NSKernAttributeName:@1.5f NSDictionary *dic = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@1.5f}; NSAttributedString *attributeStr = [[NSAttributedString alloc] initWithString:str attributes:dic]; label.attributedText = attributeStr; } //计算UILabel的高度(带有行间距的情况) -(CGFloat)getSpaceLabelHeight:(NSString*)str withFont:(UIFont*)font withWidth:(CGFloat)width { NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init]; paraStyle.lineBreakMode = NSLineBreakByCharWrapping; paraStyle.alignment = NSTextAlignmentLeft; paraStyle.lineSpacing = 7; paraStyle.hyphenationFactor = 1.0; paraStyle.firstLineHeadIndent = 0.0; paraStyle.paragraphSpacingBefore = 0.0; paraStyle.headIndent = 0; paraStyle.paragraphSpacing = 15; NSDictionary *dic = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@1.5f}; CGSize size = [str boundingRectWithSize:CGSizeMake(width, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:dic context:nil].size; return size.height; } |
