Ios 如何将CGContextRef保存为.PNG文件?
我创建了一个绘图iOS应用程序,我想在其中创建一个“保存图像”方法。 绘图在touchesMoved:方法中进行Ios 如何将CGContextRef保存为.PNG文件?,ios,cocoa-touch,cgcontextref,Ios,Cocoa Touch,Cgcontextref,我创建了一个绘图iOS应用程序,我想在其中创建一个“保存图像”方法。 绘图在touchesMoved:方法中进行 - (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; [self drawToCache:touch]; [self setNeedsDisplay]; } - (void) drawToCache:(
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
[self drawToCache:touch];
[self setNeedsDisplay];
}
- (void) drawToCache:(UITouch*)touch {
hue += 0.005;
if(hue > 1.0) hue = 0.0;
UIColor *color = [UIColor colorWithHue:hue saturation:0.7 brightness:1.0 alpha:1.0];
CGContextSetStrokeColorWithColor(cacheContext, [color CGColor]);
CGContextSetLineCap(cacheContext, kCGLineCapRound);
CGContextSetLineWidth(cacheContext, 15);
CGPoint lastPoint = [touch previousLocationInView:self];
CGPoint newPoint = [touch locationInView:self];
CGContextMoveToPoint(cacheContext, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(cacheContext, newPoint.x, newPoint.y);
CGContextStrokePath(cacheContext);
CGRect dirtyPoint1 = CGRectMake(lastPoint.x-10, lastPoint.y-10, 20, 20);
CGRect dirtyPoint2 = CGRectMake(newPoint.x-10, newPoint.y-10, 20, 20);
[self setNeedsDisplayInRect:CGRectUnion(dirtyPoint1, dirtyPoint2)];
}
我想把我画的东西保存到一个.PNG文件中
有解决方案吗?非常简单:
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:@"myImage.png"];
问题很简单:
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:@"myImage.png"];
您需要实际设置路径位置。扩展CrimsonDiego的代码,这将把图像放在应用程序的/Documents目录中
NSString*docsDirectory=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)objectAtIndex:0];
NSString*path=[docsdirectorystringbyappendingpathcomponent:@“myImage.png”];
UIImage*image=UIGraphicsGetImageFromCurrentImageContext();
NSData*imageData=UIImagePNGRepresentation(图像);
[imageData WriteFile:原子路径:是];
您需要实际设置路径位置。扩展CrimsonDiego的代码,这将把图像放在应用程序的/Documents目录中
NSString*docsDirectory=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)objectAtIndex:0];
NSString*path=[docsdirectorystringbyappendingpathcomponent:@“myImage.png”];
UIImage*image=UIGraphicsGetImageFromCurrentImageContext();
NSData*imageData=UIImagePNGRepresentation(图像);
[imageData WriteFile:原子路径:是];
此解决方案对我不起作用。文件未出现在我的应用程序文件夹中(~/Library/application Support/iPhone Simulator/5.1/Applications/CCAA9512-D2D6-4312-83D6-A4A9F74906C3/*)。我应该在哪里写这段代码?这个解决方案不适合我。文件未出现在我的应用程序文件夹中(~/Library/application Support/iPhone Simulator/5.1/Applications/CCAA9512-D2D6-4312-83D6-A4A9F74906C3/*)。我应该在哪里写这段代码?我在第“[imageData writeToFile:path];”行得到一个错误。错误:“NSData”没有可见的@interface声明选择器“writeToFile:”使用正确的方法编辑了我的答案,writeToFile:原子性:如果此答案对您有帮助,请接受它。我在“[imageData writeToFile:path];”行遇到错误。错误:“NSData”没有可见的@interface声明选择器“writeToFile:”使用正确的方法编辑了我的答案,writeToFile:原子性:如果此答案对您有帮助,请接受它。可能重复的可能重复的