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我正在使用CGlayers用於繪圖，正如文檔所述，它是在畫布上繪製繪圖的更高效的方法。CGlayer繪圖性能低下
我基本上拉入CGlayers和繪製層成使用CGContextDrawLayerInRect
這裏圖形上下文是我的drawRect方法
- (void)drawRect:(CGRect)rect
{
switch (m_drawStep)
{
case DRAW:
{
CGContextRef context = UIGraphicsGetCurrentContext();//Get a reference to current context(The context to draw)
if(self.currentDrawingLayer == nil)//Potential leak of memory- static analyzer
{
CGFloat scale = self.contentScaleFactor;
CGRect bounds = CGRectMake(0, 0, self.bounds.size.width * scale, self.bounds.size.height * scale);
CGLayerRef layer = CGLayerCreateWithContext(context, bounds.size, NULL);
CGContextRef layerContext = CGLayerGetContext(layer);
CGContextScaleCTM(layerContext, scale, scale);
self.currentDrawingLayer = layer;
}
CGContextRef layerContext = CGLayerGetContext(self.currentDrawingLayer);//Potential leak of memory- static analyzer
CGContextBeginPath(layerContext);
CGContextAddPath(layerContext, mutablePath);
CGContextSetLineWidth(layerContext, self.lineWidth);
CGContextSetStrokeColorWithColor(layerContext, self.lineColor.CGColor);
CGContextSetFillColorWithColor(layerContext, self.lineColor.CGColor);
CGContextSetBlendMode(layerContext,kCGBlendModeNormal);
CGContextStrokePath(layerContext);
CGPathRelease(mutablePath);
CGContextDrawLayerInRect(context, self.bounds, self.currentDrawingLayer);//Potential leak of memory- static analyzer
}
break;
case UNDO:
{
CGContextRef context = UIGraphicsGetCurrentContext();
if(self.currentDrawingLayer == nil)//Potential leak of memory- static analyzer
{
CGFloat scale = self.contentScaleFactor;
CGRect bounds = CGRectMake(0, 0, self.bounds.size.width * scale, self.bounds.size.height * scale);
CGLayerRef layer = CGLayerCreateWithContext(context, bounds.size, NULL);
CGContextRef layerContext = CGLayerGetContext(layer);
CGContextScaleCTM(layerContext, scale, scale);
self.currentDrawingLayer = layer;
}
CGContextRef layerContext1 = CGLayerGetContext(self.currentDrawingLayer);//Potential leak of memory- static analyzer
CGContextClearRect(layerContext1, self.bounds);
for(NSArray *undoArray in m_parentUndoArray)
{
for(int i =0; i<[undoArray count];i++)
{
DrawingPath *drawPath = [undoArray objectAtIndex:i];
CGPathRef path = drawPath.path.CGPath;
mutablePath = CGPathCreateMutableCopy(path);
CGContextBeginPath(layerContext1);
CGContextAddPath(layerContext1, mutablePath);
CGContextSetLineWidth(layerContext1, drawPath.pathWidth.floatValue);
CGContextSetStrokeColorWithColor(layerContext1, drawPath.pathColor.CGColor);
if([drawPath.pathColor isEqual:[UIColor clearColor]])
{
CGContextSetBlendMode(layerContext1,kCGBlendModeClear);
}
else
{
CGContextSetBlendMode(layerContext1,kCGBlendModeNormal);
}
CGContextStrokePath(layerContext1);
CGPathRelease(mutablePath);
}
}
CGContextDrawLayerInRect(context, self.bounds, self.currentDrawingLayer);//Potential leak of memory- static analyzer
}
}
break;
[super drawRect:rect];
}
以我的觸摸已移至函數功能，我創建UIBezeirPath和將其轉換爲CGPath。
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
self.currentPath = [[DrawingPath alloc] init];
if(m_eraseButtonClicked)
{
[self.currentPath setPathColor:[UIColor clearColor]];
}
else
{
[self.currentPath setPathColor:self.lineColor];
}
CGPathRef cgPath = self.currentPath.path.CGPath;
mutablePath = CGPathCreateMutableCopy(cgPath);
[m_undoArray addObject:self.currentPath];
[self setNeedsDisplay];
}
在觸摸結束
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[m_parentUndoArray addObject:[NSArray arrayWithArray:m_undoArray]];
}
其中，我所面臨的問題是以下
1）I與時間探查測試，CGContextDrawLayerInRect，需要90％的時間，同時繪製，所以我想知道如何減少這種方法所花費的時間並優化drawRect方法。 2）如果我畫幾條冗長的線並開始不斷地撤消/重做，那麼你也可以看到CGContextDrawLayerInRect這需要很多時間。 3）如果我刪除了一些畫線並重復進行撤消/重做，更糟糕的是，我的應用程序崩潰了內存警告，我不知道擦除出了什麼問題，它花費了太多內存。
編輯：代碼，更新，以顯示在靜態分析說，他們是內存問題
Is Instruments是否報告泄漏儀器存在任何內存泄漏？你有殭屍啓用（這將導致釋放內存永遠不會被釋放）？您是否在代碼中使用Xcode中的靜態分析器來查看它是否報告了有關內存管理的任何問題？ – Gavin
你好@Gavin，它報告與CoreGraphics功能的內存泄漏，我不知道殭屍，我沒有運行任何靜態分析器 – Ranjit
我運行靜態分析器，其報告的問題在上面的代碼行，我已更新。 – Ranjit