Quartz2D drawing and iosquartz2d drawing developed by IOS

Quartz2D drawing and iosquartz2d drawing developed by IOS

// Customize the drawing and call the drawRect Method

-(Void) drawRect :( CGRect) rect {

// Obtain the context first

CGContextRef context = UIGraphicsGetCurrentContext ();

// [Self drawLine: context];

}

# Pragma mark-draw a line

-(Void) drawLine :( CGContextRef) context

{

// 1. Obtain the context

// Context

// 2. Create the drawn path (path)

// Path

// The CGPathRef variable

// CGMutablePathRef variable path

CGMutablePathRef path = CGPathCreateMutable ();

// Set the start point

CGPathMoveToPoint (path, NULL, 50, 50 );

// Connect to the next point

CGPathAddLineToPoint (path, NULL, 200,200 );

CGPathAddLineToPoint (path, NULL, 50,200 );

// Close the path

CGPathCloseSubpath (path );

// 3. Add the path to the context

CGContextAddPath (context, path );

// 4. Set context attributes

// Line color

CGContextSetRGBStrokeColor (context, 41/255. 0, 110/255. 0, 222/255. 0, 1 );

// Fill color

CGContextSetRGBFillColor (context, 150/255. 0, 50/255. 0, 100/255. 0, 1 );

// Line width

CGContextSetLineWidth (context, 5 );

// Connection point style

CGContextSetLineJoin (context, kCGLineJoinRound );

// 5. Draw the path

/*

KCGPathFill, // only fill

KCGPathEOFill, // unique or

KCGPathStroke, // draw only lines

KCGPathFillStroke, // fill and draw line

KCGPathEOFillStroke

*/

CGContextDrawPath (context, kCGPathFillStroke );

// 6. Release path

CGPathRelease (path );

}

# Pragma mark-draw a rectangle

-(Void) drawShapeRect :( CGContextRef) context

{

// Method 1

/*

// Set the area to be drawn

CGRect rect = CGRectMake (40, 40,100,200 );

// Add the region to the context

CGContextAddRect (context, rect );

// How to set the color of the UIKit package

[[UIColor redColor] setStroke];

[[UIColor blueColor] setFill];

// Draw

CGContextDrawPath (context, kCGPathFillStroke );

*/

// Method 2

// UIKit

CGRect rect = CGRectMake (40, 40,100,200 );

[[UIColor redColor] setStroke];

[[UIColor blueColor] setFill];

// Call to directly start plotting

UIRectFill (rect); // fill

UIRectFrame (rect); // framework

 

}

# Pragma mark-draw a circle

-(Void) drawCircle :( CGContextRef) context

{

// Circle

/*

* X, y center

* Radius

* StartAngle endAngle angle (unit: radian)

* Clockwise 0/counter-clockwise 1

*/

// CGContextAddArc (context, 160,200, 50, 0, M_PI_2, 1 );

// Incircle

CGRect rect = CGRectMake (50, 50,200,100 );

[[UIColor orangeColor] setStroke];

UIRectFrame (rect );

CGContextAddEllipseInRect (context, CGRectMake (50, 50,200,100 ));

[[UIColor redColor] setStroke];

[[UIColor brownColor] setFill];

CGContextDrawPath (context, kCGPathFillStroke );

}

# Pragma mark-besell Curve

-(Void) drawCurve :( CGContextRef) context

{

// Start point

CGContextMoveToPoint (context, 20, 50 );

/*

* 1x, 1y end point of the first tangent

* 2x, 2y start point of the second tangent

* The end point of the second tangent of x and y

*/

// CGContextAddCurveToPoint (context, 100, 20,200,300,300, 50 );

CGContextAddQuadCurveToPoint (context, 160, 20,300,200 );

CGContextDrawPath (context, kCGPathStroke );

}

# Pragma mark-draw text

-(Void) drawText :( CGContextRef) context

{

// 1. Drawn text

NSString * str = @ "wxhl34 ";

// 2. Define the drawn Area

CGRect rect = CGRectMake (50, 50,200, 50 );

UIRectFrame (rect );

// 3. Set the drawn style

// Text paragraph style

NSMutableParagraphStyle * style = [[NSMutableParagraphStyle defaultParagraphStyle] mutableCopy];

Style. lineBreakMode = NSLineBreakByCharWrapping;

Style. alignment = NSTextAlignmentRight;

NSDictionary * attr = @{

NSFontAttributeName: [UIFont systemFontOfSize: 20],

NSParagraphStyleAttributeName: style

};

// 4. Draw

[Str drawInRect: rect withAttributes: attr];

}

# Pragma mark-draw an image

-(Void) drawImage :( CGContextRef) context

{

// Image

UIImage * image = [UIImage imageNamed: @ "baymax.jpg"];

// 1. Draw from the specified point

[Image drawAtPoint: CGPointMake (20,400)];

// 2. drawing in the specified area will automatically stretch

// [Image drawInRect: CGRectMake (0, 0,100,200)];

// Coordinate System Conversion

// CG UIKit

// Save the current context

CGContextSaveGState (context );

// CGContextTranslateCTM (context, 0,200 );

// Returns the inverse of the Y axis.

CGContextScaleCTM (context, 1,-1 );

// Move the Y axis up 200

CGContextTranslateCTM (context, 0,-200 );

/*

CGContextRotateCTM (context, M_PI); // rotate

CGContextScaleCTM (context,-1, 1); // zoom

CGContextTranslateCTM (context, 0,-200); // Translation

*/

// CG

// UIImage --> CGImageRef

// UIKit Core Graphics AppKit

CGContextDrawImage (context, CGRectMake (0, 0,320,200), image. CGImage );

// Restore the saved Context

CGContextRestoreGState (context );

}