Question

我想拍摄具有固定分辨率的图像。需要强制用户裁剪图像。我需要一个方形图像。

我正在使用下一个代码，它只是通过宽屏分辨率裁剪。

self.imagepicker = [[UIImagePickerController alloc]init];
self.imagepicker.delegate = self;
self.imagepicker.allowsEditing=YES;
self.imagepicker.preferredContentSize = CGSizeMake(200, 200);

self.imagepicker.sourceType=UIImagePickerControllerSourceTypePhotoLibrary;

[self presentViewController:self.imagepicker animated:YES completion:nil];

Answer 1

preferredContentSize不是UIImagePickerController本身的属性，而是任何UIViewController的属性，因为它嵌入在UIPopoverController中。

您需要自己展示裁剪界面。

Answer 2

如果您想在选择图像后完成，请尝试使用此代码作为中心裁剪图像

- (UIImage *)squareImageFromImage:(UIImage *)image scaledToSize:(CGFloat)newSize1
{
    CGAffineTransform scaleTransform;
    CGPoint origin;
    CGFloat newSize;

    if (image.size.width > image.size.height)
    {
        newSize=image.size.height;
        CGFloat scaleRatio = newSize / image.size.height;
        scaleTransform = CGAffineTransformMakeScale(scaleRatio, scaleRatio);
        origin = CGPointMake(-(image.size.width - image.size.height) / 2.0f, 0);
    }
    else
    {
        newSize=image.size.width;
        CGFloat scaleRatio = newSize / image.size.width;
        scaleTransform = CGAffineTransformMakeScale(scaleRatio, scaleRatio);
        origin = CGPointMake(0, -(image.size.height - image.size.width) / 2.0f);
    }

    CGSize size = CGSizeMake(newSize, newSize);
    if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
        UIGraphicsBeginImageContextWithOptions(size, YES, 0);
    } else {
        UIGraphicsBeginImageContext(size);
    }

    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextConcatCTM(context, scaleTransform);

    [image drawAtPoint:origin];

    image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;
}

对你有帮助。感谢

为PickerController设置最大图像分辨率？

2 个答案: