1、使用UIBezierPath 繪製圖形 http://my.oschina.net/lanrenbar/blog/389379 http://justsee.iteye.com/blog/1972853
2.、使用CGContextRef進行圖形繪製 http://blog.csdn.net/rhljiayou/article/details/9919713
3、使用CAGradientLayer可以方便的處理顏色漸變
4、畫虛線用CAShapeLayer
圖片處理
1、按某個區域對圖片進行放大處理
userLine.image = image?.resizableImageWithCapInsets(UIEdgeInsetsMake(0, 150, 10, 10), resizingMode: UIImageResizingMode.Stretch)
2、圖片任意角度旋轉
//圖片旋轉任意角度
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、圖片固定角度旋轉
// 2D仿射變換
只能旋轉一次(有make)
_aView.transform = CGAffineTransformMakeRotation(M_PI_4);
//可以實現多次旋轉.(無make),一般都是成對出現
_aView.transform = CGAffineTransformRotate(_aView.transform, M_PI_4);
//實現動畫,平緩過多使用Block語法
[UIViewanimateWithDuration:0.5animations:^{
_aView.transform =CGAffineTransformRotate(_aView.transform,M_PI_4);
}];
//3D放射變換 1.導入QuartzCore框架 2.引入頭文件#import <QuartzCore/CATransform3D.h>
_imageView.layer.transform =CATransform3DRotate(_imageView.layer.transform,M_PI_4, 0,0, 1);
4、圖片保存到本地相冊
-(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:@"未授權杏仁醫生訪問相冊，保存失敗"];
}];
//
}
else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"請授權" message:@"請至 設置->隱私->照片 設置允許訪問通相冊" delegate:self cancelButtonTitle:@"確定" otherButtonTitles: nil];
[alert show];
}
return true;
}
-(void)image:(UIImage *)imaged didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
if(!error) {
[SVProgressHUD showSuccessWithStatus:@"成功保存到相冊"];
}
else {
[SVProgressHUD showErrorWithStatus:@"保存失敗"];
}
}