After drawing a path you can render it to an image. That way each path is concatenated into a single image that will be far more efficient for drawing. Please see this question for code snippets.
Keep previous UIBezierPath strokes on successive calls to drawRect
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16-07-2023 - |
質問
I would like to mention that this post is similar to Continuous drawing in CGContext with drawRect but it didn't have any code snippet solution so asking again.
I am learning iOS development application. I am trying to make a drawing application using UIBezierPath. For the moment to whenever I have a new touch and a new UIBezierPath
I do the following to show my previous UIBezierPath
. Please let me know if there is better/recommended way. I have color array to keep track of color used to draw each beizer path as I have option of changing color for each path.
- (void)drawRect:(CGRect)rect // (4)
{
UIBezierPath *currentPath;
UIColor *currentColor;
for (int index=0;index<[self.pathArray count]; index++)
{
currentPath = [self.pathArray objectAtIndex:index];
currentColor = [self.strokeArray objectAtIndex:index];
[currentColor setStroke];
[currentPath stroke];
}
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint p = [touch locationInView:self];
UIColor *currentStrokeColor;
currentStrokeColor = [self copyColor:self.strokeColor];
self.path = [UIBezierPath bezierPath];
[self.path setLineWidth:2.0];
[self.pathArray addObject:self.path];
[self.strokeArray addObject:currentStrokeColor];
[self.path moveToPoint:p];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint p = [touch locationInView:self];
[self.path addLineToPoint:p]; // (4)
[self setNeedsDisplay];
}
解決
所属していません StackOverflow