开发笔记

---

获取当前控制器(UIView)

• 代码：

- (UIViewController *)currentViewController {
    UIWindow * window = [[UIApplication sharedApplication] keyWindow];
    if (window.windowLevel != UIWindowLevelNormal){
        NSArray *windows = [[UIApplication sharedApplication] windows];
        for(UIWindow * tmpWin in windows){
            if (tmpWin.windowLevel == UIWindowLevelNormal){
                window = tmpWin;
                break;
            }
        }
    }
    UIViewController *result = window.rootViewController;
    while (result.presentedViewController) {
        result = result.presentedViewController;
    }
    if ([result isKindOfClass:[UITabBarController class]]) {
        result = [(UITabBarController *)result selectedViewController];
    }
    if ([result isKindOfClass:[UINavigationController class]]) {
        result = [(UINavigationController *)result topViewController];
    }
    return result;
}

---

获取当前控制器(NSObj)

• 代码：

#pragma 获取当前控制器
- (UIViewController *)currentViewController {
    UIViewController* viewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    return [self findBestViewController:viewController];
}

- (UIViewController*)findBestViewController:(UIViewController*)vc {
    if (vc.presentedViewController) {
        return [self findBestViewController:vc.presentedViewController];
    } else if ([vc isKindOfClass:[UISplitViewController class]]) {
        UISplitViewController* svc = (UISplitViewController*)vc;
        if (svc.viewControllers.count > 0) {
            return [self findBestViewController:svc.viewControllers.lastObject];
        } else {
            return vc;
        }
    } else if ([vc isKindOfClass:[UINavigationController class]]) {
        UINavigationController* nvc = (UINavigationController*)vc;
        if (nvc.viewControllers.count > 0) {
            return [self findBestViewController:nvc.topViewController];
        } else {
            return vc;
        }
    } else if ([vc isKindOfClass:[UITabBarController class]]) {
        UITabBarController* tvc = (UITabBarController*)vc;
        if (tvc.viewControllers.count) {
            return [self findBestViewController:tvc.selectedViewController];
        } else {
            return vc;
        }
    } else {
        return vc;
    }
}

---

画一个虚线图(UIImage分类方法)

• 使用方法：

  • self.textView.layer.contents = (id)[UIImage imageWithSize:self.textView.bounds.size borderColor:RGBA(0xB8C1CE, 0.7) borderWidth:1.0f].CGImage;

• 代码：

+ (UIImage*)imageWithSize:(CGSize)size borderColor:(UIColor *)color borderWidth:(CGFloat)borderWidth {
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0);
    [[UIColor clearColor] set];
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextBeginPath(context);
    CGContextSetLineWidth(context, borderWidth);
    CGContextSetStrokeColorWithColor(context, color.CGColor);
    CGFloat lengths[] = { 3, 1 };
    CGContextSetLineDash(context, 0, lengths, 1);
    CGContextMoveToPoint(context, 0.0, 0.0);
    CGContextAddLineToPoint(context, size.width, 0.0);
    CGContextAddLineToPoint(context, size.width, size.height);
    CGContextAddLineToPoint(context, 0, size.height);
    CGContextAddLineToPoint(context, 0.0, 0.0);
    CGContextStrokePath(context);
    UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image; 
}

---

圆角图(UIImage分类方法)

• 使用方法：

  • UIImage *placeHolder = [UIImage imageNamed:@"defaultUserIcon"].roundImage;

• 代码：

- (UIImage *)roundImage {
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0.0);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGRect rect = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height);
    CGContextAddEllipseInRect(ctx, rect);
    CGContextClip(ctx);
    [self drawRect:rect];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

---

1.获取富文本字典（2和3都基于这个富文本）

• 代码：

- (NSDictionary *)getAttributesDict {
    NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paraStyle.alignment = NSTextAlignmentLeft;
    paraStyle.lineSpacing = 1.0f; //设置行间距
    paraStyle.hyphenationFactor = 0.5;
    paraStyle.firstLineHeadIndent = 0.0;
    paraStyle.paragraphSpacingBefore = 0.0;
    paraStyle.headIndent = 0;
    paraStyle.tailIndent = 0;
    //设置字间距 NSKernAttributeName:@0.5f
    NSDictionary *dict = @{NSFontAttributeName:[UIFont systemFontOfSize:14.0f], NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@0.5f };
    return dict;
}

2.传入一个lable,并设置行间距和字间距

• 代码：

- (void)setLabelFont:(UILabel *)label {
    NSAttributedString *attributeStr = [[NSAttributedString alloc] initWithString:label.text attributes:[self getAttributesDict]];
    label.attributedText = attributeStr;
}

3.计算由“2”设置的Label高度

• 代码：

- (CGFloat)getSpaceLabelHeight: (NSString *)string LabelWidth: (CGFloat)labelWidth {
    CGSize size = [string boundingRectWithSize:CGSizeMake(labelWidth, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:[self getAttributesDict] context:nil].size;
    return size.height;
}

获取单行label宽度

• 代码：

- (CGFloat)sigleLineLabelWidth:(UILabel *)label {
    CGSize size =[self.timeLabel.text sizeWithAttributes:@{NSFontAttributeName:label.font}];
    return size.width;
}

---

获取 UITextView 的光标位置

• 代码：

CGFloat cursorPosition = [textView caretRectForPosition:textView.selectedTextRange.start].origin.y;

---

超出父控件接受点击

• 代码：

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    if (!self.isUserInteractionEnabled || self.isHidden || self.alpha <= 0.01) {
        return nil;
    }
    /**
     *  此注释掉的方法用来判断点击是否在父View Bounds内，
     *  如果不在父view内，就会直接不会去其子View中寻找HitTestView，return 返回
     */
    //    if ([self pointInside:point withEvent:event]) {
    for (UIView *subview in self.subviews) {
        CGPoint convertedPoint = [subview convertPoint:point fromView:self];
        UIView *hitTestView = [subview hitTest:convertedPoint withEvent:event];
        if (hitTestView) {
            return hitTestView;
        }
    }
    return [super hitTest:point withEvent:event];
    //    }
    return nil;
}

---

扩大点击热区

• 代码：

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
    return    CGRectContainsPoint(HitTestingBounds(self.bounds, 200, 300), point);
    }

    CGRect HitTestingBounds(CGRect bounds, CGFloat minimumHitTestWidth, CGFloat minimumHitTestHeight) {
    CGRect hitTestingBounds = bounds;
    if (minimumHitTestWidth > bounds.size.width) {
        hitTestingBounds.size.width = minimumHitTestWidth;
        hitTestingBounds.origin.x -= (hitTestingBounds.size.width - bounds.size.width)/2;
    }
    if (minimumHitTestHeight > bounds.size.height) {
        hitTestingBounds.size.height = minimumHitTestHeight;
        hitTestingBounds.origin.y -= (hitTestingBounds.size.height - bounds.size.height)/2;
    }
    return hitTestingBounds;
 }

---

转移点击处理

• 代码：

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    UIView *hitTestView = [super hitTest:point withEvent:event];
    if (hitTestView) {
        hitTestView = self.scrollView;
    }
    return hitTestView;
}

---

Enumerator使用

• 代码：

-  (void)objectEnumeratorWithArray: (NSArray *)array {
    NSLog(@"------- 枚举器法---------");
    //ObjectEnumerator        正序
    //reverseObjectEnumerator 逆序
    NSEnumerator *enumerator = [array reverseObjectEnumerator];
    id obj = nil;
    while (obj = [enumerator nextObject]) {
        NSLog(@"%@", obj);
    }
    
    //2.倒序的数组
    NSArray* reversedArray = [[array reverseObjectEnumerator] allObjects];
}

---

生成条形码

• 代码：

- (UIImage *)generateBarCode:(NSString *)code width:(CGFloat)width height:(CGFloat)height {
    //生成条形码图片
    CIImage *barcodeImage;
    NSData *data = [code dataUsingEncoding:NSISOLatin1StringEncoding allowLossyConversion:false];
    CIFilter *filter = [CIFilter filterWithName:@"CICode128BarcodeGenerator"];
    [filter setValue:data forKey:@"inputMessage"];
    barcodeImage = [filter outputImage];
    //消除模糊
    CGFloat scaleX = width / barcodeImage.extent.size.width; 
    CGFloat scaleY = height / barcodeImage.extent.size.height;
    CIImage *transformedImage = [barcodeImage imageByApplyingTransform:CGAffineTransformScale(CGAffineTransformIdentity, scaleX, scaleY)];
    return [UIImage imageWithCIImage:transformedImage];
}

---

RAC使用

• 代码：

- (void)rac_map_function {
    RACSignal *signal = [RACSignal createSignal:^RACDisposable *(id subscriber) {
        [subscriber sendNext:@"A signal"];
        [subscriber sendCompleted];
        return [RACDisposable disposableWithBlock:^{
        }];
    }];
    signal = [signal map:^id(id value) {
        return @"B signal";
    }];
    [signal subscribeNext:^(id x) {
        NSLog(@"%@", x);
    }];
}

---

透明图

• 代码：

- (UIImage *)image {
    //self.navigationController.navigationBar.translucent = YES;
    UIGraphicsBeginImageContext(self.navigationController.navigationBar.frame.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0 green:0 blue:0 alpha:0.4].CGColor);
    CGContextFillRect(context, self.navigationController.navigationBar.frame);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    //[self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
    return image;
}

---

App版本号

• 代码：

//Version
[[[NSBundle mainBundle]infoDictionary]valueForKey:@"CFBundleShortVersionString"];
//Build
[[[NSBundle mainBundle]infoDictionary]valueForKey:@"CFBundleVersion"];

---

调整UIButton上下显示

• 代码：

CGFloat margin = 12.0f;
CGSize imageSize = button.imageView.frame.size;
CGSize titleSize = button.titleLabel.frame.size;
button.titleEdgeInsets = UIEdgeInsetsMake(0, -imageSize.width, -imageSize.height-margin, 0);
 button.imageEdgeInsets = UIEdgeInsetsMake(-titleSize.height-margin, 0, 0, -titleSize.width);

---

二维码的生成

• 代码：

- (UIImage *)createQRCode:(NSString *)code length: (CGFloat)length {
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [filter setDefaults];
    NSData *infoData = [code dataUsingEncoding:NSUTF8StringEncoding];
    [filter setValue:infoData forKeyPath:@"inputMessage"];
    CIImage *outImage = [filter outputImage];
    return [self createNonInterpolatedUIImageFormCIImage:outImage length:length];
}

//根据CIImage生成指定大小的UIImage
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image length:(CGFloat) length {
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(length/CGRectGetWidth(extent), length/CGRectGetHeight(extent));
    
    // 1.创建bitmap;
    size_t width = CGRectGetWidth(extent) * scale;
    size_t height = CGRectGetHeight(extent) * scale;
    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    
    // 2.保存bitmap到图片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

配置隐私权限 保存到相册=============
Privacy - Photo Library Additions Usage Description
UIImageWriteToSavedPhotosAlbum(shareImg, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
并实现代理
-(void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    NSString *msg = nil ;
    if(error){
        msg = @"保存图片失败" ;
    }else{
        msg = @"保存图片成功" ;
    }
}
====================

//生成图片(屏幕截图)
- (UIImage *)creatShareImage {
    UIGraphicsBeginImageContextWithOptions(self.imgView.frame.size, NO, 2.0);
    [self.imgView.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *shareImg = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return shareImg;
}

环境配置

• 代码：

#ifdef DEBUG
//开发环境
#define kUrlApi         @"https://develop.com"

#else
//正式环境
#define kUrlApi         @"https://release.com"
#endif