从摄像头或者是从相册中读取图片，需要通过UIImagePickerController类来实现，在使用UIImagePickerController时，需要是实现下面两个协议
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<uinavigationcontrollerdelegate,uiimagepickercontrollerdelegate></uinavigationcontrollerdelegate,uiimagepickercontrollerdelegate> |
1、从相册中读取图片
首先要实例化UIImagePickerController对象imagePicker，设置imagePicker的图片来源为UIImagePickerControllerSourceTypePhotoLibrary，表明当前图片的来源为用户的相册。以及设置图片是否可被编辑allowsEditing。
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#pragma mark - 从用户相册获取图片- (void)pickImageFromAlbum{ imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate =self; imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical; imagePicker.allowsEditing =YES; [self presentModalViewController:imagePicker animated:YES];} |
2、从相册中读取图片
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#pragma mark - 从摄像头获取图片- (void)pickImageFromCamera{ imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate =self; imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera; imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical; imagePicker.allowsEditing =YES; [self presentModalViewController:imagePicker animated:YES];}//打开相机- (IBAction)touch_photo:(id)sender { // for iphone UIImagePickerController *pickerImage = [[UIImagePickerController alloc] init]; if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { pickerImage.sourceType = UIImagePickerControllerSourceTypeCamera; pickerImage.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:pickerImage.sourceType]; } pickerImage.delegate =self; pickerImage.allowsEditing =YES;//自定义照片样式 [self presentViewController:pickerImage animated:YES completion:nil];} |
在用户现则好图片后，会回调选择结束的方法
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-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info{ //初始化imageNew为从相机中获得的-- UIImage *imageNew = [info objectForKey:@UIImagePickerControllerOriginalImage]; //设置image的尺寸 CGSize imagesize = imageNew.size; imageSize.height =626; imageSize.width =413; //对图片大小进行压缩-- imageNew = [self imageWithImage:imageNew scaledToSize:imageSize]; NSData *imageData = UIImageJPEGRepresentation(imageNew,0.00001); if(m_selectImage==nil) { m_selectImage = [UIImage imageWithData:imageData]; NSLog(@m_selectImage:%@,m_selectImage); [self.takePhotoButton setImage:m_selectImage forState:UIControlStateNormal]; [picker dismissModalViewControllerAnimated:YES]; return ; }} |
对图片进行压缩
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-(UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize{ // Create a graphics image context UIGraphicsBeginImageContext(newSize); // Tell the old image to draw in this new context, with the desired // new size [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)]; // Get the new image from the context UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext(); // End the context UIGraphicsEndImageContext(); // Return the new image. return newImage;} |
将图片保存到Documents目录及PNG、JPEG格式相互转换
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- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary*)info { NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType]; if ([mediaType isEqualToString:@public.image]){ image = [info objectForKey:@UIImagePickerControllerOriginalImage]; NSData *data; if (UIImagePNGRepresentation(image) == nil) { data = UIImageJPEGRepresentation(image, 1); } else { data = UIImagePNGRepresentation(image); } NSFileManager *fileManager = [NSFileManager defaultManager]; NSString *filePath = [NSString stringWithString:[self getPath:@image1]]; //将图片存储到本地documents [fileManager createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:nil]; [fileManager createFileAtPath:[filePath stringByAppendingString:@/image.png] contents:dataAttributes:nil]; UIImage *editedImage = [[UIImage alloc] init]; editedImage = image; CGRect rect = CGRectMake(0, 0, 64, 96); UIGraphicsBeginImageContext(rect.size); [editedImage drawInRect:rect]; editedImage = UIGraphicsGetImageFromCurrentImageContext(); UIButton *imageButton = [UIButton buttonWithType:UIButtonTypeCustom]; imageButton.frame = CGRectMake(10, 10, 64, 96); [imageButton setImage:editedImage forState:UIControlStateNormal]; [self.view addSubview:imageButton]; [imageButton addTarget:self action:@selector(imageAction:)forControlEvents:UIControlEventTouchUpInside]; [self dismissModalViewControllerAnimated:YES]; } else { NSLog(@Media); } |
在上面的方法中不能得到图片的名称及格式，所以需要将其转换成NSData二进制存储
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image = [info objectForKey:@UIImagePickerControllerOriginalImage];NSData *data; if (UIImagePNGRepresentation(image) == nil) { data = UIImageJPEGRepresentation(image, 1); } else { data = UIImagePNGRepresentation(image); } |
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[fileManager createFileAtPath:[filePath stringByAppendingString:@/image.png] contents:data attributes:nil]; //将图片保存为PNG格式 [fileManager createFileAtPath:[filePath stringByAppendingString:@/image.jpg |
原文：http://www.cnblogs.com/LiLihongqiang/p/5597371.html