使用的iOS绘图方法

最新推荐文章于 2025-03-18 11:11:14 发布

原创最新推荐文章于 2025-03-18 11:11:14 发布 · 343 阅读

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#iOS #图片操作 #UI

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给图片添加水印图片

+ (instancetype)waterImageWithBg:(NSString *)bg logo:(NSString *)logo
{
    
    UIImage * bgImage = [UIImage imageNamed:bg];
    
    UIGraphicsBeginImageContextWithOptions(bgImage.size, NO, 0.0);
    
    [bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)];
    
    UIImage * waterimage = [UIImage imageNamed:logo];
    CGFloat scale = 0.2;
    CGFloat waterW = waterimage.size.width * scale;
    CGFloat waterH = waterimage.size.height * scale;
    CGFloat waterX =bgImage.size.width-waterimage.size.width-10;
    CGFloat waterY = bgImage.size.height - waterimage.size.height-10;
    [waterimage drawInRect:CGRectMake(waterX, waterY, waterW, waterH)];
    
    UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    return newImage;
}

2.裁剪图片

+ (instancetype)circleImageWithName:(NSString *)name borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor
{
   
     //1.加载原图
    UIImage *oldImage = [UIImage imageNamed:name];
    
    // 2.开启上下文
    CGFloat imageW = oldImage.size.width + 2 * borderWidth;
    CGFloat imageH = oldImage.size.height + 2 * borderWidth;
    CGSize imageSize = CGSizeMake(imageW, imageH);
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);
    
    // 3.取得当前的上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    // 4.画边框(大圆)
    [borderColor set];
    CGFloat bigRadius = imageW * 0.5; // 大圆半径
    CGFloat centerX = bigRadius; // 圆心
    CGFloat centerY = bigRadius;
    CGContextAddArc(ctx, centerX, centerY, bigRadius, 0, M_PI * 2, 0);
//
    CGContextFillPath(ctx); // 画圆
//    
//    // 5.小圆
//    CGFloat smallRadius = bigRadius - borderWidth;
//    CGContextAddArc(ctx, centerX, centerY, smallRadius, 0, M_PI * 2, 0);
//    /**
//     *
//     */
//    // 裁剪(后面画的东西才会受裁剪的影响)
    CGContextClip(ctx);
//    // 6.画图
//    [oldImage drawInRect:CGRectMake(borderWidth, borderWidth, oldImage.size.width, oldImage.size.height)];
//    // 7.取图
   UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
//    // 8.结束上下文
//    UIGraphicsEndImageContext();
    return newImage;
}

截屏

+ (instancetype)captureWithView:(UIView *)view
{
    // 1.开启上下文
    UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
    
    // 2.将控制器view的layer渲染到上下文
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    
    // 3.取出图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    // 4.结束上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}