iOS学习：调用相机，选择图片上传，带预览功能

2019-11-08 00:26:43

字体：大中小

来源：转载

供稿：网友

一、新建工程

二、拖控件，创建映射

三、在.h中加入delegate

@interface ViewController : UIViewController<UIActionSheetDelegate,UIImagePickerControllerDelegate,UINavigationControllerDelegate>

四、实现按钮事件

-(IBAction)chooseImage:(id)sender { UIActionSheet *sheet;

// 判断是否支持相机

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { sheet = [[UIActionSheet alloc] initWithTitle:@"选择" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"拍照",@"从相册选择", nil]; } else { sheet = [[UIActionSheet alloc] initWithTitle:@"选择" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"从相册选择", nil]; } sheet.tag = 255; [sheet showInView:self.view]; }

五、实现actionSheet delegate事件

判断是否支持相机，跳转到相机或相册界面

-(void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{ if (actionSheet.tag == 255) { NSUInteger sourceType = 0; // 判断是否支持相机 if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { switch (buttonIndex) { case 0: // 取消 return; case 1: // 相机 sourceType = UIImagePickerControllerSourceTypeCamera; break; case 2: // 相册 sourceType = UIImagePickerControllerSourceTypePhotoLibrary; break; } } else { if (buttonIndex == 0) { return; } else { sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; } }

// 跳转到相机或相册页面

UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init]; imagePickerController.delegate = self; imagePickerController.allowsEditing = YES; imagePickerController.sourceType = sourceType; [self PResentViewController:imagePickerController animated:YES completion:^{}]; [imagePickerController release]; }}六、实现ImagePicker delegate 事件#pragma mark - image picker delegte- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ [picker dismissViewControllerAnimated:YES completion:^{}]; UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage]; /* 此处info 有六个值 * UIImagePickerControllerMediaType; // an NSString UTTypeImage) * UIImagePickerControllerOriginalImage; // a UIImage 原始图片 * UIImagePickerControllerEditedImage; // a UIImage 裁剪后图片 * UIImagePickerControllerCropRect; // an NSValue (CGRect) * UIImagePickerControllerMediaURL; // an NSURL * UIImagePickerControllerReferenceURL // an NSURL that references an asset in the AssetsLibrary framework * UIImagePickerControllerMediaMetadata // an NSDictionary containing metadata from a captured photo */ // 保存图片至本地，方法见下文 [self saveImage:image withName:@"currentImage.png"]; NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImage.png"]; UIImage *savedImage = [[UIImage alloc] initWithContentsOfFile:fullPath]; isFullScreen = NO; [self.imageView setImage:savedImage]; self.imageView.tag = 100; }- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{ [self dismissViewControllerAnimated:YES completion:^{}];}

七、保存图片高保真压缩图片方法

NSData * UIImageJPEGRepresentation ( UIImage *image, CGFloat compressionQuality)此方法可将图片压缩，但是图片质量基本不变，第二个参数即图片质量参数。 #pragma mark - 保存图片至沙盒- (void) saveImage:(UIImage *)currentImage withName:(NSString *)imageName{ NSData *imageData = UIImageJPEGRepresentation(currentImage, 0.5); // 获取沙盒目录 NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:imageName]; // 将图片写入文件 [imageData writeToFile:fullPath atomically:NO];}

八、实现点击图片预览功能，滑动放大缩小，带动画

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ isFullScreen = !isFullScreen; UITouch *touch = [touches anyObject]; CGPoint touchPoint = [touch locationInView:self.view]; CGPoint imagePoint = self.imageView.frame.origin; //touchPoint.x ，touchPoint.y 就是触点的坐标 // 触点在imageView内，点击imageView时放大,再次点击时缩小 if(imagePoint.x <= touchPoint.x && imagePoint.x +self.imageView.frame.size.width >=touchPoint.x && imagePoint.y <= touchPoint.y && imagePoint.y+self.imageView.frame.size.height >= touchPoint.y) { // 设置图片放大动画 [UIView beginAnimations:nil context:nil]; // 动画时间 [UIView setAnimationDuration:1]; if (isFullScreen) { // 放大尺寸 self.imageView.frame = CGRectMake(0, 0, 320, 480); } else { // 缩小尺寸 self.imageView.frame = CGRectMake(50, 65, 90, 115); } // commit动画 [UIView commitAnimations]; } }九、上传图片，使用ASIhttpRequest类库实现，由于本文重点不是网络请求，故不对ASIHttpRequest详细讲述，只贴出部分代码ASIFormDataRequest *requestReport = [[ASIFormDataRequest alloc] initWithURL:服务器地址]; NSString *Path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImage.png"]; [requestReport setFile:Path forKey:@"picturepath"];[requestReport buildPostBody];requestReport.delegate = self;[requestReport startAsynchronous];

效果图如下：