没有排版，看的感觉不舒服，重新排版转发一下了（有部分删减掉了）

一、调用代码使APP进入后台，达到点击Home键的效果。（私有API）

[[UIApplication sharedApplication] performSelector:@selector(suspend)];复制代码

suspend的英文意思：悬、挂、暂停

二、获取UIWebView的高度 个人

- (void)webViewDidFinishLoad:(UIWebView *)webView  {     CGFloat height = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];      CGRect frame = webView.frame;      webView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, height);   }复制代码

三、UITableView收起键盘何必这么麻烦 一个属性搞定，效果好（UIScrollView同样可以使用） 以前是不是觉得[self.view endEditing:YES];很屌，这个下面的更屌。

yourTableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeOnDrag;复制代码

四、设置UILable  的行间距  和 计算带行间距的高度

/*UILabel* 展示的控件(NSString*)str  内容withFont:(float)font 字体大小WithSpace:(float)space 行间距*///给UILabel设置行间距和字间距-(void)setLabelSpace:(UILabel*)label withValue:(NSString*)str withFont:(float)font WithSpace:(float)space{NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];paraStyle.lineBreakMode = NSLineBreakByCharWrapping;paraStyle.alignment = NSTextAlignmentLeft;paraStyle.lineSpacing = space; //设置行间距paraStyle.hyphenationFactor = 1.0;paraStyle.firstLineHeadIndent = 0.0;paraStyle.paragraphSpacingBefore = 0.0;paraStyle.headIndent = 0;paraStyle.tailIndent = 0;//设置字间距 NSKernAttributeName:@1.5fUIFont *tfont = [UIFont systemFontOfSize:font];NSDictionary *dic = @{NSFontAttributeName:tfont, 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)(NSString*)str  内容withFont:(float)font 字体大小WithSpace:(float)space 行间距(CGFloat)width  UILable的宽度*///计算UILabel的高度(带有行间距的情况)-(CGFloat)getSpaceLabelHeight:(NSString*)str withFont:(float)font withWidth:(CGFloat)width WithSpace:(float)space{NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];paraStyle.lineBreakMode = NSLineBreakByCharWrapping;paraStyle.alignment = NSTextAlignmentLeft;paraStyle.lineSpacing = space;paraStyle.hyphenationFactor = 1.0;paraStyle.firstLineHeadIndent = 0.0;paraStyle.paragraphSpacingBefore = 0.0;paraStyle.headIndent = 0;paraStyle.tailIndent = 0;UIFont *tfont = [UIFont systemFontOfSize:font];NSDictionary *dic = @{NSFontAttributeName:tfont, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@1.5f};CGSize size = [str boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:dic context:nil].size;return size.height;}复制代码

五、 禁止程序运行时自动锁屏

[[UIApplication sharedApplication] setIdleTimerDisabled:YES];复制代码

六、CocoaPods pod install/pod update更新慢的问题

pod install –verbose –no-repo-update pod update –verbose –no-repo-update 复制代码

如果不加后面的参数，默认会升级CocoaPods的spec仓库，加一个参数可以省略这一步，然后速度就会提升不少。

七、修改textFieldplaceholder字体颜色和大小

textField.placeholder = @"请输入用户名";  [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"]; [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];复制代码

八、禁止textField和textView的复制粘贴菜单

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender{    	if ([UIMenuController sharedMenuController]) {      		[UIMenuController sharedMenuController].menuVisible = NO;   		}     	return NO;  }复制代码

九、级三级页面隐藏系统tabbar 1、单个处理

YourViewController *yourVC = [YourViewController new];yourVC.hidesBottomBarWhenPushed = YES;[self.navigationController pushViewController:yourVC animated:YES];复制代码

十、取消系统的返回手势

self.navigationController.interactivePopGestureRecognizer.enabled = NO;复制代码

十一、添加pch文件的步聚

1：创建新文件 ios->other->PCH file，创建一个pch文件：“工程名-Prefix.pch”：2：将building setting中的precompile header选项的路径添加“$(SRCROOT)/项目名称/pch文件名”（例如：$(SRCROOT)/LotteryFive/LotteryFive-Prefix.pch）3：将Precompile Prefix Header为YES，预编译后的pch文件会被缓存起来，可以提高编译速度复制代码