UIImage 图片处理

1.等比率缩放

 1 //等比率缩放
 2 - (UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize {
 3     //设置图片的上下文
 4     UIGraphicsBeginImageContext(CGSizeMake(image.size.width*scaleSize, image.size.height*scaleSize));
 5     //绘制图片的大小
 6     [image drawInRect:CGRectMake(0, 0, image.size.width*scaleSize, image.size.height*scaleSize)];
 7     //生成新的图片
 8     UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
 9     //结束上下文的编辑
10     UIGraphicsEndImageContext();
11     //返回图片
12     return scaledImage;
13 }

2.自定义宽高

 1 //自定长宽
 2 - (UIImage *)reSizeImage:(UIImage *)image toSize:(CGSize)reSize {
 3     //设置上下文
 4     UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height));
 5     //重定义大小
 6     [image drawInRect:CGRectMake(0, 0, reSize.width, reSize.height)];
 7     //生成新图片
 8     UIImage *reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
 9     //结束上下文
10     UIGraphicsEndImageContext();
11     //返回图片
12     return reSizeImage;
13 }

3.处理某个特定的view

 1 //处理某个特定的view
 2 - (UIImage *)captureView:(UIView *)theView {
 3     //取得当前view的frame
 4     CGRect rect = theView.frame;
 5     //开始上下文
 6     UIGraphicsBeginImageContext(rect.size);
 7     //
 8     CGContextRef context = UIGraphicsGetCurrentContext();
 9     //
10     [theView.layer renderInContext:context];
11     //将view转换为图片
12     UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
13     //结束上下文
14     UIGraphicsEndImageContext();
15     //返回图片
16     return img;
17 }

其中，在view里面实现

1 UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
2         imageView.image = [UIImage imageNamed:@"1.jpg"];
3         [self addSubview:imageView];

4.存储图片,存到app的文件里

 1 - (void)saveImage:(UIImage *)image image:(int)location{
 2     if (location == 1) {
 3         //存储路径，以及存储的文件名字
 4         NSString *path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"xiaoye.png"];
 5         //将图片写入文件
 6         [UIImagePNGRepresentation(image) writeToFile:path atomically:YES];
 7         //找到Documents文件目录
 8         NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
 9         //输出Documents目录下得文件名字
10         NSLog(@"存储到docments目录下的文件有:%@",[[NSFileManager defaultManager] subpathsAtPath:docPath]);
11     }
12 }

5.在viewdidload里测试

 1  UIImage *image = [UIImage imageNamed:@"1.jpg"];
 2     
 3     //等比率的缩放
 4     UIImage *scaledImage = [self scaleImage:image toScale:0.5f];
 5     NSLog(@"%@",scaledImage);
 6     
 7     //自定长宽
 8     UIImage *reSizeImage = [self reSizeImage:image toSize:CGSizeMake(100.0f, 50.0f)];
 9     NSLog(@"%@",reSizeImage);
10     
11     //处理特定的view，继承自uiview，需要导入QuzrtzCore.framework
12     MyView *view = [[MyView alloc] initWithFrame:CGRectMake(0, 0, 160, 240)];
13     UIImage *img = [self captureView:view];
14     NSLog(@"%@",img);
15     
16     //存储图片到Documents目录下
17     [self saveImage:image image:1];
18     
19     //测试图片，scaledImage，reSizeImage，img
20     self.view.backgroundColor = [UIColor colorWithPatternImage:img];

 

 

 

posted on 2014-04-22 18:42  李园春秋  阅读(235)  评论(0)  编辑  收藏  举报

导航