问在objective C中用户自定义裁剪
EN

Stack Overflow用户

提问于 2014-11-05 10:24:56

回答 3查看 1K关注 0票数 2

我使用UIImagePickerController获取imageView的图像，如下所示

 -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *originalImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
    CGSize destinationSize1 = CGSizeMake(200, 200);
    UIGraphicsBeginImageContext(destinationSize1);
    [originalImage drawInRect:CGRectMake(0,0,destinationSize1.width,destinationSize1.height)];
    UIImage *newImage1 = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    firstimage1.image = newImage1;
    [picker dismissViewControllerAnimated:YES completion:nil];

    NSLog(@"image width is %f",firstimage1.image.size.width);
    NSLog(@"image height is %f",firstimage1.image.size.height);
   if (firstimage1.image.size.width==200 && firstimage1.image.size.height==200) {
    UIAlertView *alertcrp=[[UIAlertView alloc]initWithTitle:@"message!" message:@"you want to crop this image" delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:nil];
       [alertcrp addButtonWithTitle:@"Crop "];
        [alertcrp show];
        }
}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    NSLog(@"Button Index =%ld",(long)buttonIndex);
    if (buttonIndex == 0)
    {
        NSLog(@"You have clicked Cancel");
    }
    else if(buttonIndex == 1)
    {
   UIImagePickerController *controller = [[UIImagePickerController alloc] init];

        controller.allowsEditing = YES; // this will allow you to crop the image first
        controller.delegate = self;

        [self presentViewController:controller animated:YES completion:nil];

    }
}

我们调整图像大小到200*200。现在我需要的是当用户上传图像.If图像上传成功，然后打开alertView“如果你想裁剪图像”。单击裁剪按钮后，我需要打开矩形裁剪视图。

请告诉我关于我的高级problem.Thanks的任何想法。

objective-c

uiimageview

uiimagepickercontroller

crop

ios

回答 3

Stack Overflow用户

发布于 2014-11-05 13:34:37

你需要做的事情很简单。首先创建一个你想要裁剪的裁剪大小的UIScrollView，你可以让它动态，如果你想通过平移手势等，但我已经做了恒定裁剪大小，所以我不会进入细节。接下来，创建一个与原始图像大小相同的UIImageView，并将其image proprety设置为该大小。还要将scorllview's content size属性设置为与图像大小完全相同的值。允许弹跳有一些额外的效果。然后，在按下裁剪时，你只需要将想要裁剪的滚动视图的内容偏移和大小(即滚动视图的大小，即它的宽度和高度)传递给这个函数。

- (UIImage *)crop:(UIImage *)image inRect:(CGRect)cropRect
{
    CGImageRef cropRef = CGImageCreateWithImageInRect(image.CGImage, cropRect);
    UIImage* cropImage = [UIImage imageWithCGImage:cropRef];
    CGImageRelease(cropRef);

    return cropImage;
}

您可以按照上面的描述调用此方法，如下所示

UIImage * img = [[CommonFunctions sharedManager] crop:imgView.image inRect:CGRectMake(scrollView.contentOffset.x , scrollView.contentOffset.y , reqWidth, reqHeight)];

根据您的逻辑使rect用于裁剪可能存在错误。但你应该对做什么有大致的了解。如果有什么事情让你困惑，或者它是否有帮助，请告诉我，这样我也许可以进一步帮助你:)

票数 1

Stack Overflow用户

发布于 2014-11-05 10:32:16

要调整图像的大小，请使用此命令

UIGraphicsBeginImageContext(CGSizeMake(200, 200));
[myImage drawInRect:CGRectMake(0, 0, 200, 200)]; // Size of your ne image
UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

票数 0

Stack Overflow用户

发布于 2014-11-05 10:58:26

UIImagePickerController *controller = [[UIImagePickerController alloc] init];

controller.allowsEditing = YES; // this will allow you to crop the image first
controller.delegate = self;

[self presentViewController:controller animated:YES completion:nil];