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;
}
