iOS 中的一些视图、图片处理

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开发中不可避免的会遇到一些图片和视图的处理，我这里总结的这些只是我遇到的一些，以供下次使用查看。

图片的旋转

是UIImage的扩展类，直接使用UIImage的对象调用即可

#import 
#import 

@implementation UIImage (ImageRotate)
-(UIImage *)imageRotateIndegree:(float)degree{
    //1.image-》context
    size_t width = (size_t)(self.size.width *self.scale);
    size_t height = (size_t)(self.size.height*self.scale);
    
    size_t bytesPerRow = width * 4;//表明每行图片数据字节
    CGImageAlphaInfo alphaInfo = kCGImageAlphaPremultipliedFirst;//alpha
    //配置上下文参数
    CGContextRef bmContext = CGBitmapContextCreate(NULL, width, height, 8, bytesPerRow, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrderDefault | alphaInfo);
    if (!bmContext) {
        return nil;
    }
    CGContextDrawImage(bmContext, CGRectMake(0, 0, width, height), self.CGImage);
    //2旋转
    UInt8 *data = (UInt8*)CGBitmapContextGetData(bmContext);
    vImage_Buffer src = {data,height,width,bytesPerRow};
    vImage_Buffer dest = {data,height,width,bytesPerRow};
    Pixel_8888 bgColor = {0,0,0,0};
    vImageRotate_ARGB8888(&src, &dest, NULL, degree, bgColor, kvImageBackgroundColorFill);
    //3context-》UIImage
    CGImageRef rotateImageref = CGBitmapContextCreateImage(bmContext);
    UIImage *rotateImage = [UIImage imageWithCGImage:rotateImageref scale:self.scale orientation:self.imageOrientation];
    return rotateImage;
}
@end

图片的裁剪

依然是UIImage的扩展类，直接使用UIImage的对象调用即可

@implementation UIImage (ImageCut)

-(UIImage *)ImageCutSize:(CGRect)rect{
    CGImageRef subImageref = CGImageCreateWithImageInRect(self.CGImage, rect);
    CGRect smallRef = CGRectMake(0, 0, CGImageGetWidth(subImageref), CGImageGetHeight(subImageref));
    
    UIGraphicsBeginImageContext(smallRef.size);
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextDrawImage(context, smallRef, subImageref);
    UIImage *image = [UIImage imageWithCGImage:subImageref];
    
    UIGraphicsEndImageContext();
    return image;
}
@end

获取截屏

截屏是UIView的扩展类

@implementation UIView (imageScreenShot)
- (UIImage *)imageScreenShot
{
    UIGraphicsBeginImageContext(self.frame.size);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *imageNew = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return imageNew;
}
@end

使用方法

- (void)imageScreen{
    UIImage *imageNew = [self.view imageScreenShot];
    UIImageWriteToSavedPhotosAlbum(imageNew, nil, nil, nil);  //直接保存在相册里，要获取相册权限
}

图片比例处理

依然是UIImage的扩展类

@implementation UIImage (imageScaleSize)

- (UIImage *) scaleImage:(UIImage *)image toScale:(float)scaleSize{
    UIGraphicsBeginImageContext(CGSizeMake(image.size.width * scaleSize, image.size.height * scaleSize));
    [image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height * scaleSize)];
    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
     return scaledImage;
}
@end

view添加圆角

这里是UIView的扩展类，适用于所有的View，可以设置添加的位置

@implementation UIView (LSCore)

/**
 设置部分圆角 绝对布局

 @param corners 需要设置为圆角的角 UIRectCornerTopLeft|UIRectCornerTopRight
 @param radii 需要设置的圆角大小 CGSizeMake(5.0, 5.0)
 */
- (void)addRoundedCorners:(UIRectCorner)corners withRadii:(CGSize)radii{
    UIBezierPath *rounded = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:radii];
    CAShapeLayer *shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    self.layer.mask = shape;
}


/**
 设置部分圆角 相对布局

 @param corners 需要设置为圆角的角 UIRectCornerTopLeft|UIRectCornerTopRight

 @param radii 需要设置的圆角大小 CGSizeMake(5.0, 5.0)
 @param rect 需要设置的圆角view的rect
 */
- (void)addRoundedCorners:(UIRectCorner)corners withRadii:(CGSize)radii viewRect:(CGRect)rect{
    UIBezierPath *rounded = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:radii];
    CAShapeLayer *shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    self.layer.mask = shape;
}
@end

使用方法以UIImageView为例

[image addRoundedCorners:UIRectCornerTopLeft|UIRectCornerTopRight withRadii:CGSizeMake(20.0, 20.0)];

将颜色转为图片

-(UIImage *)ImageForColor:(UIColor *)color{
    CGRect rect = CGRectMake(0.0f, 0.0f, 10, 10);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

图片添加系统滤镜

-(UIImage *)blurryImage:(UIImage *)image
          withBlurLevel:(CGFloat)blur {
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"
                                  keysAndValues:kCIInputImageKey, inputImage,
                        @"inputRadius", @(blur),
                        nil];
    
    CIImage *outputImage = filter.outputImage;
    CGImageRef outImage = [context createCGImage:outputImage
                                        fromRect:[outputImage extent]];
    
    return [UIImage imageWithCGImage:outImage];
}

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