void drawLine(){
NSLog(@"--------------------------------画线段--------------------------------");
//获取图形上下文对象
CGContextRef context = UIGraphicsGetCurrentContext();
//将当前上下文对象copy一份，放到图形上下文栈的栈顶
CGContextSaveGState(context);
//设置起点
CGContextMoveToPoint(context, 10, 10);
//添加线段至某一点
CGContextAddLineToPoint(context, 100, 100);
//设置颜色
[[UIColor redColor] setStroke];
//设置线的粗细
CGContextSetLineWidth(context, 10);
//设置线的端点形状
CGContextSetLineCap(context, kCGLineCapRound);
//渲染显示到view上
CGContextStrokePath(context);
//将上面存储到上下文栈里面的上下文对象取出来，用它t去替换上面设置属性的上下文
CGContextRestoreGState(context);
//这里的上下文是从栈里新取出来的，上面设置的属性对这里无效
CGContextMoveToPoint(context, 15, 5);
CGContextAddLineToPoint(context, 120, 40);
CGFloat lengths[] = {5,10}; //分别是点的长度，空白的长度
//第二个参数phase参数表示在第一个虚线绘制的时候跳过多少个点；第三个参数lengths表示点和空白的长度；第四个参数count，是lengths数组的长度
CGContextSetLineDash(context, 0, lengths,2);
CGContextStrokePath(context);
}
void drawTriangle(){
NSLog(@"--------------------------------画三角--------------------------------");
//获取图形上下文对象
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
//设置起点
CGContextMoveToPoint(context, 10, 10);
//添加线段至某一点
CGContextAddLineToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 50);
//
[[UIColor redColor] setFill];
//封闭路径
CGContextClosePath(context);
//渲染显示到view上
CGContextFillPath(context);
CGContextRestoreGState(context);
//平移
CGContextTranslateCTM(context, 0, 50);
//缩放
CGContextScaleCTM(context, 1.5, 0.5);
// 旋转
CGContextRotateCTM(context, M_PI * 0.2);
//设置起点
CGContextMoveToPoint(context, 10, 10);
//添加线段至某一点
CGContextAddLineToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 50);
//阴影，offset：x轴和y轴偏移的距离，blue模糊程度
CGContextSetShadow(context, CGSizeMake(100, 5), 5);
[[UIColor blueColor] setFill];
//封闭路径
CGContextClosePath(context);
//渲染显示到view上
CGContextFillPath(context);
}
void drar4Rect()
{
NSLog(@"--------------------------------画四边形--------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddRect(context, CGRectMake(10, 10, 30, 100));
// CGContextSetLineJoin(context, kCGLineJoinRound);
CGContextSetLineWidth(context, 10);
[[UIColor blueColor] setStroke];
CGContextStrokePath(context);
// CGContextAddRect(context, CGRectMake(10, 10, 30, 100));
// [[UIColor redColor] setFill];
// CGContextFillPath(context);
}
void drawArc()
{
NSLog(@"--------------------------------画圆弧--------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
/**
上下文
x坐标
y坐标
半径
起始角度
结束角度
0顺时针 1逆时针
x轴正向为0度，y轴x向下为90度，x轴反向为180度，y轴向上为270度
*/
CGContextAddArc(context, 100, 100, 20, 0, M_PI_2, 0);
CGContextStrokePath(context);
}
void drawCircle()
{
NSLog(@"--------------------------------画圆--------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddEllipseInRect(context, CGRectMake(100, 100, 60, 60));
CGContextStrokePath(context);
}
void drawsquCircle(){
NSLog(@"--------------------------------画1/4圆--------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 100, 130);
CGContextAddArc(context, 100, 100, 30, M_PI_2, 0, 1);
CGContextClosePath(context);
//画边
CGContextStrokePath(context);
//画内部
// CGContextFillPath(context);
}
void drawText(){
NSLog(@"--------------------------------画文本-------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(20, 20, 100, 100);
CGContextAddRect(context, rect);
CGContextFillPath(context);
NSString * str = @"画出来点文本";
NSMutableDictionary * dic = [NSMutableDictionary dictionary];
//设置文本字体大小
dic[NSFontAttributeName] = [UIFont systemFontOfSize:14];
//设置文本颜色
dic[NSForegroundColorAttributeName] = [UIColor redColor];
//在矩形范围内画文本
[str drawInRect:rect withAttributes:dic];
}
void drawImage(){
NSLog(@"--------------------------------画图片-------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(0, 0, 240, 240);
[[UIColor redColor] set];
CGContextAddRect(context, rect);
CGContextFillPath(context);
UIImage * image = [UIImage imageNamed:@"me"];
// 绘制一次,按矩形大小去绘制图片
// [image drawInRect:rect];
//重复绘制
[image drawAsPatternInRect:rect];
}
void drawTextAndImage(){
NSLog(@"--------------------------------画图片和文本-------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(5, 5, 200, 200);
CGContextAddRect(context, rect);
CGContextFillPath(context);
//画图片
UIImage * image = [UIImage imageNamed:@"me"];
[image drawInRect:rect];
//画文本
NSString * str = @"画出来点文本";
NSMutableDictionary * dic = [NSMutableDictionary dictionary];
//设置文本字体大小
dic[NSFontAttributeName] = [UIFont systemFontOfSize:14];
//设置文本颜色
dic[NSForegroundColorAttributeName] = [UIColor redColor];
//在矩形范围内画文本
// [str drawInRect:rect withAttributes:dic];
[str drawInRect:CGRectMake(150 , 150, 200, 200) withAttributes:dic];
}
void drawQuadCurve(CGContextRef context ,CGRect rect){
NSLog(@"--------------------------------画贝塞尔曲线-------------------------------");
//控制点
CGFloat controlX = rect.size.width * 0.5;
CGFloat controlY = rect.size.height * 0.4;
//开始点
CGFloat leftMargin = 30;
CGFloat startX = controlX - leftMargin;
CGFloat startY = controlY - 20;
CGContextMoveToPoint(context, startX, startY);
//结束点
CGFloat endX = controlX + leftMargin;
CGFloat endY = startY;
//画贝塞尔曲线
CGContextAddQuadCurveToPoint(context, controlX, controlY, endX, endY);
//
CGContextStrokePath(context);
}
void drawClip(){
NSLog(@"--------------------------------裁剪-------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(10, 10, 50, 50);
CGContextAddEllipseInRect(context, rect);
//设置裁剪
CGContextClip(context);
CGContextFillPath(context);
UIImage * image = [UIImage imageNamed:@"me"];
[image drawAtPoint:CGPointMake(10, 10)];
}
void drawWithPath(){
NSLog(@"--------------------------------使用path画图形-------------------------------");
CGContextRef context = UIGraphicsGetCurrentContext();
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, 10, 10);
CGPathAddLineToPoint(path, NULL, 150, 100);
CGContextAddPath(context, path);
CGContextStrokePath(context);
//释放
CGPathRelease(path);
}
