iOS UIPickerController 调用相机，选择图片上传，带预览功能

在.h中加入delegate

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

//实现按钮事件

-(IBAction)chooseImage:(id)sender {
     
    UIActionSheet *sheet;
<p>
// 判断是否支持相机
</p>
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];
     
}

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;
            }
        }
<p>
// 跳转到相机或相册页面
</p>
UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
         
        imagePickerController.delegate = self;
         
        imagePickerController.allowsEditing = YES;
         
        imagePickerController.sourceType = sourceType;
         
        [self presentViewController:imagePickerController animated:YES completion:^{}];
         
        [imagePickerController release];
    }
}

实现ImagePicker] delegate 事件

- (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:^{}];
}

 保存图片方法

	
#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];
}

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];
         
    }
     
}