1、使用UIBezierPath 绘制图形 http://my.oschina.net/lanrenbar/blog/389379 http://justsee.iteye.com/blog/1972853
2.、使用CGContextRef进行图形绘制 http://blog.csdn.net/rhljiayou/article/details/9919713
3、使用CAGradientLayer可以方便的处理颜色渐变
4、画虚线用CAShapeLayer
图片处理
1、按某个区域对图片进行放大处理
userLine.image = image?.resizableImageWithCapInsets(UIEdgeInsetsMake(0, 150, 10, 10), resizingMode: UIImageResizingMode.Stretch)
2、图片任意角度旋转
//图片旋转任意角度
CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees
{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,20, 20)];
CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, DegreesToRadians(degrees));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-20 / 2, -20 / 2, 20, 20), [UIImage imageNamed:@"1(2)@2x"].CGImage);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
3、图片固定角度旋转
// 2D仿射变换
只能旋转一次(有make)
_aView.transform = CGAffineTransformMakeRotation(M_PI_4);
//可以实现多次旋转.(无make),一般都是成对出现
_aView.transform = CGAffineTransformRotate(_aView.transform, M_PI_4);
//实现动画,平缓过多使用Block语法
[UIViewanimateWithDuration:0.5animations:^{
_aView.transform =CGAffineTransformRotate(_aView.transform,M_PI_4);
}];
//3D放射变换 1.导入QuartzCore框架 2.引入头文件#import <QuartzCore/CATransform3D.h>
_imageView.layer.transform =CATransform3DRotate(_imageView.layer.transform,M_PI_4, 0,0, 1);
4、图片保存到本地相册
-(BOOL)savePhotoAlbum:(UIImage *)image
{
ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];
if (status == ALAuthorizationStatusAuthorized)
{
UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
}
else if(status == ALAuthorizationStatusNotDetermined)
{
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupLibrary usingBlock:nil failureBlock:nil];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
} failureBlock:^(NSError *error) {
[SVProgressHUD showErrorWithStatus:@"未授权杏仁医生访问相册，保存失败"];
}];
//
}
else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"请授权" message:@"请至 设置->隐私->照片 设置允许访问通相册" delegate:self cancelButtonTitle:@"确定" otherButtonTitles: nil];
[alert show];
}
return true;
}
-(void)image:(UIImage *)imaged didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
if(!error) {
[SVProgressHUD showSuccessWithStatus:@"成功保存到相册"];
}
else {
[SVProgressHUD showErrorWithStatus:@"保存失败"];
}
}