Bézier curves & cashapelayer & Stroke Animations

Reprinted from: http://46aae4d1e2371e4aa769798941cef698.devproxy.yunshipei.com/qiaoqiaoqiao2014/article/details/46928787

1.CAShapeLayer Introduction

1.1CAShapeLayer inherits from Calayer and can use all the property values of Calayer;

1.2CAShapeLayer requires Bézier curves to be used in order to make sense (that is, to have effects)

1.3 Using Cashapelayer (belonging to coreanimation) and Bezier curves can be implemented in the DrawRect of the view (inherited from the Coregraphics walk is the CPU, the performance of a large consumption) method to draw some desired graphics

1.4CAShapeLayer animation rendering is submitted directly to the GPU of the phone, which is highly efficient compared to the DrawRect method of view, and can greatly optimize memory usage

2.CAShapeLayer use

2.1 Code Show

1. The relationship between Bezier curves and Cashapelayer

1.1CAShapeLayer requires a shape to take effect, a Bezier curve can create a vector-based path, which in turn provides a path to Cashapelayer, and the path is closed-loop.

The 1.2 Bezier curve is the path of the Cashapelayer, whose path is a closed-loop, end-to-end curve.

2. Practical Application

2.2 Draw Ellipse

2.2 Draw a rectangle, the method of drawing a circle is consistent with the top, but the method called when drawing is inconsistent.

3. Note: Bezier curves and Cashapelayer frame values do not interfere, Bezier is only to be placed on the Cashapelayer layer, So the frame.size of Cashapelayer cannot be less than the frame.size of the Bezier curve,Maskstobounds is a property of Cashapelayer, The path that prohibits Bezier curves extends beyond the frame range of Cashapelayer.

4.StrokeStart and the use of strokeend

4.1 Usage steps:

4.1.1 Set the FillColor of shapelayer into a transparent color

4.1.2 Set the width of the edge line

4.1.3 Set the color of the edge line

4.1.4 Set the Strokestart value to 0 to change the value of strokeend, triggering an implicit animation

4.1.5 uses a timer to make it change

4.2 Case Application

, this is the gradient sliding, similar to the buckle landing of the waiting rotation view, you can go to my blog resources to download the demo Oh.

Bézier curves & cashapelayer & Stroke Animations