ios生成圆角图片

////原文出处忘了哪里了，很抱歉

头文件

#import <UIKit/UIKit.h>typedef enum {    UIImageRoundedCornerTopLeft = 1,    UIImageRoundedCornerTopRight = 1 << 1,    UIImageRoundedCornerBottomRight = 1 << 2,    UIImageRoundedCornerBottomLeft = 1 << 3} UIImageRoundedCorner;@interface MainViewController : UIViewController{}-(void)addRoundedRectToPath:(CGContextRef)context withrect:(CGRect)rect radius:(float)radius mask:(UIImageRoundedCorner)cornerMask;- (UIImage *)roundedRectImage:(UIImage *)srcimage withradius:(float)radius cornerMask:(UIImageRoundedCorner)cornerMask;@end

实现文件

#import "MainViewController.h"#import <stdio.h>#import <stdlib.h>#import "FileUtil.h"@implementation MainViewController#pragma mark - View lifecycle// Implement loadView to create a view hierarchy programmatically, without using a nib.- (void)loadView{[super loadView];self.view.backgroundColor = [UIColor blueColor];UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];[button1 setTitle:@"button111" forState:UIControlStateNormal];[button1 setTitle:@"button111" forState:UIControlStateHighlighted];button1.frame = CGRectMake(0, 0, 300, 50);[button1 addTarget:self action:@selector(writetofile) forControlEvents:UIControlEventTouchUpInside];[self.view addSubview:button1];UIButton *button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];[button2 setTitle:@"button2222" forState:UIControlStateNormal];[button2 setTitle:@"button2222" forState:UIControlStateHighlighted];button2.frame = CGRectMake(0, 80, 300, 50);[button2 addTarget:self action:@selector(readfile) forControlEvents:UIControlEventTouchUpInside];[self.view addSubview:button2];UIImage *srcimg = [UIImage imageNamed:@"test.png"];NSLog(@"image width = %f,height = %f",srcimg.size.width,srcimg.size.height);UIImageView *imgview = [[UIImageView alloc] initWithFrame:CGRectMake(10, 150, 300, 220)];imgview.image = [self roundedRectImage:srcimg withradius:10 cornerMask:UIImageRoundedCornerTopLeft|UIImageRoundedCornerTopRight];[self.view addSubview:imgview];}- (UIImage *)roundedRectImage:(UIImage *)srcimage withradius:(float)radius cornerMask:(UIImageRoundedCorner)cornerMask{    UIImageView *bkImageViewTmp = [[[UIImageView alloc] initWithImage:srcimage] autorelease];    int w = srcimage.size.width;    int h = srcimage.size.height;    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();    CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);    CGContextBeginPath(context);[self addRoundedRectToPath:context withrect:bkImageViewTmp.frame radius:radius mask:cornerMask];     CGContextClosePath(context);    CGContextClip(context);    CGContextDrawImage(context, CGRectMake(0, 0, w, h), srcimage.CGImage);    CGImageRef imageMasked = CGBitmapContextCreateImage(context);    CGContextRelease(context);    CGColorSpaceRelease(colorSpace);    UIImage    *newImage = [UIImage imageWithCGImage:imageMasked];    CGImageRelease(imageMasked);    return newImage;}-(void)addRoundedRectToPath:(CGContextRef)context withrect:(CGRect)rect radius:(float)radius mask:(UIImageRoundedCorner)cornerMask{    //原点在左下方，y方向向上。移动到线条2的起点。    CGContextMoveToPoint(context, rect.origin.x, rect.origin.y + radius);        //画出线条2, 目前画线的起始点已经移动到线条2的结束地方了。    CGContextAddLineToPoint(context, rect.origin.x, rect.origin.y + rect.size.height - radius);        //如果左上角需要画圆角，画出一个弧线出来。    if (cornerMask & UIImageRoundedCornerTopLeft) {                //已左上的正方形的右下脚为圆心，半径为radius， 180度到90度画一个弧线，        CGContextAddArc(context, rect.origin.x + radius, rect.origin.y + rect.size.height - radius,                        radius, M_PI, M_PI / 2, 1);    }    else {//如果不需要画左上角的弧度。从线2终点，画到线3的终点，        CGContextAddLineToPoint(context, rect.origin.x, rect.origin.y + rect.size.height);                //线3终点，画到线4的起点        CGContextAddLineToPoint(context, rect.origin.x + radius, rect.origin.y + rect.size.height);    }        //画线4的起始，到线4的终点    CGContextAddLineToPoint(context, rect.origin.x + rect.size.width - radius,                            rect.origin.y + rect.size.height);    //画右上角    if (cornerMask & UIImageRoundedCornerTopRight) {        CGContextAddArc(context, rect.origin.x + rect.size.width - radius,                        rect.origin.y + rect.size.height - radius, radius, M_PI / 2, 0.0f, 1);    }    else {        CGContextAddLineToPoint(context, rect.origin.x + rect.size.width, rect.origin.y + rect.size.height);        CGContextAddLineToPoint(context, rect.origin.x + rect.size.width, rect.origin.y + rect.size.height - radius);    }    CGContextAddLineToPoint(context, rect.origin.x + rect.size.width, rect.origin.y + radius);    //画右下角弧线    if (cornerMask & UIImageRoundedCornerBottomRight) {        CGContextAddArc(context, rect.origin.x + rect.size.width - radius, rect.origin.y + radius,                        radius, 0.0f, -M_PI / 2, 1);    }    else {        CGContextAddLineToPoint(context, rect.origin.x + rect.size.width, rect.origin.y);        CGContextAddLineToPoint(context, rect.origin.x + rect.size.width - radius, rect.origin.y);    }    CGContextAddLineToPoint(context, rect.origin.x + radius, rect.origin.y);    //画左下角弧线    if (cornerMask & UIImageRoundedCornerBottomLeft) {        CGContextAddArc(context, rect.origin.x + radius, rect.origin.y + radius, radius,                        -M_PI / 2, M_PI, 1);    }    else {        CGContextAddLineToPoint(context, rect.origin.x, rect.origin.y);        CGContextAddLineToPoint(context, rect.origin.x, rect.origin.y + radius);    }    CGContextClosePath(context);}-(void)writetofile{NSLog(@"writetofile");}-(void)readfile{NSLog(@"button click");}/*// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.- (void)viewDidLoad{    [super viewDidLoad];}*/- (void)viewDidUnload{    [super viewDidUnload];    // Release any retained subviews of the main view.    // e.g. self.myOutlet = nil;}- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{    // Return YES for supported orientations    return (interfaceOrientation == UIInterfaceOrientationPortrait);}@end