压缩图片尺寸 UIGraphicsBeginImageContext(size);[image drawInRect:CGRectMake(0, 0, size.width, size.height)]...// Use NSUInteger to prevent white blank UIGraphicsBeginImageContext(size); // Use image to draw (drawInRect...compression time // Use result image to draw, image is smaller but less compression time [resultImage drawInRect...UIGraphicsEndImageContext(); data = UIImageJPEGRepresentation(resultImage, 1); } return resultImage;} [resultImage drawInRect...ratio))); // Use NSUInteger to prevent white blank UIGraphicsBeginImageContext(size); [resultImage drawInRect
UIKit中封装了一些最常用的绘图方法 1.1 矩形 填充 UIRectFill(rect) 画线 UIRectFrame(rect) 1.2 字符串 绘制 [str drawInRect:rect...withAttributes:attr]; 1.3 图像 拉伸 [image drawInRect:rect] 绘制 [image drawAtPoint:CGPointZero]; 平铺 [image...NSStrokeWidthAttributeName:@10 }; // 绘制方式一：在限定的rect范围内进行绘制，文字会自动换行 [str drawInRect...[str drawAtPoint:CGPointMake(0, 45) withAttributes:attriStr]; } 2.7 绘制图片 使用drawInrect进行绘制 图片比区域小...drawRect:(CGRect)rect { UIImage *image = [UIImage imageNamed:@"image"]; // 方式一： [image drawInRect
floatValue] >= 4.0) { UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0); } //原图 [image drawInRect...:self.bounds]; //水印图 [mark drawInRect:rect]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext
sourceImage:(UIImage*)sourceImage { // UIGraphicsBeginImageContext(targetSize); // [sourceImage drawInRect...thumbnailRect.size.width = scaledWidth; thumbnailRect.size.height = scaledHeight; [sourceImage drawInRect...(0,0,140,182)); UIGraphicsBeginImageContext(rect.size); [[UIImage imageWithCGImage:imageRef]drawInRect...:rect]; //如果不裁剪图片可以直接画 //[image drawInRect:CGRectMake(0, 0,theSize.width, theSize.height)];...: CGRectMake(0, 0, imageWidth /heightScale , height)]; } else { [image drawInRect: CGRectMake
UIImageOrientationUp) return self; UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale); [self drawInRect...UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return normalizedImage; } 这里是利用了UIImage中的drawInRect...方法，它会将图像绘制到画布上，并且已经考虑好了图像的方向，开发文档这样解释： -drawInRect: Draws the entire image in the specified rectangle
; CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height); [icon drawInRect
:(UIImage*)sourceImage { 2 3 UIGraphicsBeginImageContext(targetSize); 4 [sourceImage drawInRect...ratio); 27 28 UIGraphicsBeginImageContext(rect.size); 29 [[UIImage imageWithCGImage:imageRef]drawInRect...CGRectMake(0,0,140,182)); UIGraphicsBeginImageContext(rect.size); [[UIImage imageWithCGImage:imageRef]drawInRect...:rect]; //如果不裁剪图片可以直接画 //[image drawInRect:CGRectMake(0, 0, theSize.width, theSize.height)]; UIImage.../ 创建一个bitmap的context//并把它设置成为当前正在使用的context UIGraphicsBeginImageContext(size); // 绘制改变大小的图片 [self drawInRect
Quartz2D知识点聚合 基本 //画图片 UIImage *image = [UIImage imageNamed:@"阿狸头像"]; [image drawInRect:...systemFontOfSize:15]; // atr[NSForegroundœColorAttributeName] = [UIColor greenColor]; [title drawInRect
/ Tell the old image to draw in this newcontext, with the desired // new size [image drawInRect
size.width, size.height)); //剪切可视范围 CGContextClip(context); //绘制边框图片 [borderImg drawInRect...CGRectMake(iconX, iconY, iconW, iconH)); //剪切可视范围 CGContextClip(context); //绘制头像 [image drawInRect
CGSizeMake(100, 100); UIGraphicsBeginImageContext( newSize );// a CGSize that has the size you want [image drawInRect
//Attributes:给文字添加一些属性,富文本 [str drawAtPoint:CGPointZero withAttributes:dict]; } 6、drawAtPoint:和drawInRect...drawAtPoint:不能够自动换行 drawInRect:能够自动换行 7、如何利用UIKit绘制一张图片？ ...drawInRect:(CGRect *)rect：在指定的rect区域内绘制整张图片，图片会按照指定区域的宽高进行缩放，所以这种方式一定可以显示完整的图片，但是会进行一些缩放。
以下代码具有内存泄露问题： // 原始方案 UIGraphicsBeginImageContextWithOptions(imageSize,YES, 0); [image drawInRect...UIGraphicsGetCurrentContext(); // CGContextDrawImage(context, imageRect, imgRef); // // [image drawInRect...asthe overlay of the new image // UIImage *imgData = [selfverticallyFlipImage:image]; // [imgData drawInRect...UIGraphicsBeginImageContext(CGSizeMake(width, height)); if (widthScale> heightScale) { [image drawInRect...: CGRectMake(0, 0, imageWidth / heightScale , height)]; } else { [image drawInRect: CGRectMake
CGRectMake(0.0, 0.0, actualWidth, actualHeight); UIGraphicsBeginImageContext(rect.size); [image drawInRect
:87.0f/255.0f blue:29.0f/255.0f alpha:1.0f]; UIImage *img = [UIImage imageNamed: @"bg.png"]; [img drawInRect
//合成新图片 UIGraphicsBeginImageContext(CGSizeMake(100, 100)); [self.image1 drawInRect...:CGRectMake(0, 0, 50, 100)]; [self.image2 drawInRect:CGRectMake(50, 0, 50, 100)]; UIImage
UIGraphicsBeginImageContext(CGSizeMake(image.size.width * scaleSize, image.size.height * scaleSize); [image drawInRect...toSize:(CGSize)reSize { UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height)); [image drawInRect
blockOperationWithBlock:^{ UIGraphicsBeginImageContext(CGSizeMake(200, 200)); [image1 drawInRect...:CGRectMake(0, 0, 100, 200)]; [image2 drawInRect:CGRectMake(100, 0, 100, 200)]; UIImage
(CGSize)reSize{ UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height)); [image drawInRect
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