爲相交的UIViews（ObjectiveC）繪製一個共同的輪廓？

Question

我有一個UIView。在這個UIView裏面，我有兩個相交的子視圖。我想在這兩個子UIViews之間畫一個共同的概要。我如何解決這個問題？

要清楚：

[mainView addSubview:subView1]; 
[mainView addSubview:subView2]; 

我要畫一個輪廓爲這兩個交叉UIView秒。

Answer 1

您可以組合兩個矩形的形狀並從最終形狀創建新的子圖層。此圖層將充當您的輪廓。

見我的代碼，它完全註釋：

// Create shape of merged rectangles 
UIBezierPath *outlinePath = [UIBezierPath bezierPathWithRect:subView1.frame]; 
[outlinePath appendPath:[UIBezierPath bezierPathWithRect:subView2.frame]]; 

// Configure the outline 
UIColor *outlineColor = [UIColor redColor]; 
CGFloat outlineWidth = 1.0f * [[UIScreen mainScreen] scale]; 

// Create shape layer representing the outline shape 
CAShapeLayer *outlineLayer = [CAShapeLayer layer]; 
outlineLayer.frame = mainView.bounds; 
outlineLayer.fillColor = outlineColor.CGColor; 
outlineLayer.strokeColor = outlineColor.CGColor; 
outlineLayer.lineWidth = outlineWidth; 

// Set the path to the layer 
outlineLayer.path = outlinePath.CGPath; 

// Add sublayer at index 0 - below everything already in the view 
// so it looks like the border 
// "outlineLayer" is in fact the shape of the combined rectangles 
// outset by layer border 
// Moving it at the bottom of layer hierarchy imitates the border 
[mainView.layer insertSublayer:outlineLayer atIndex:0]; 

輸出看起來是這樣的：

編輯：我誤解了這個問題在第一。下面是我的原始答案，其中概述了rects交集。

您可以創建另一個視圖，它將表示交叉點並將其添加到兩個子視圖的上方。它的框架是交叉的subView1和subView2frame s。只需使用其layer財產

您的代碼看起來是這樣給它明確的背景顏色和邊框：

// Calculate intersection of 2 views 
CGRect intersectionRect = CGRectIntersection(subView1.frame, subView2.frame); 

// Create intersection view 
UIView *intersectionView = [[UIView alloc] initWithFrame:intersectionRect]; 
[mainView addSubview:intersectionView]; 

// Configure intersection view (no background color, only border) 
intersectionView.backgroundColor = [UIColor clearColor]; 
intersectionView.layer.borderColor = [UIColor redColor].CGColor; 
intersectionView.layer.borderWidth = 1.0f;