我想在 UIImagePickerController 上添加一个自定义覆盖视图,这个覆盖视图只支持横向模式。我只希望 UIImagePickerController 在横向模式下拍照。有什么办法可以做到这一点...?
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2 回答
0
我用两种不同的方法创建了两个不同的叠加层,调用与方向匹配的任何一个。
- (IBAction)takePicture:(id)sender {
[[UIDevice currentDevice]beginGeneratingDeviceOrientationNotifications];
if (UIDeviceOrientationIsPortrait([UIDevice currentDevice].orientation)) {
[self portraitDisplayOverlay];
}else{
[self startCameraControllerFromViewController:self usingDelegate:self];
}
}
在肖像覆盖上,我设置 UIImagePickerController 属性以隐藏相机控件
picker.showCameraControls = NO;
此叠加层只是指示用户使用横向模式,当它倾斜到横向时调用正确的叠加层并瞧。
希望这会有所帮助,吉姆。
于 2013-08-02T12:38:38.967 回答
0
请阅读说明 UIImagePickerController 类仅支持纵向模式的 Apple 文档:单击此处
请注意,如果您在横向模式下调用 UIImagePickerController,您的应用可能会被 Apple 拒绝
您必须找到另一种方法,例如使用 AVFoundation 框架创建自定义相机
或者
试试这个方法将你拍摄的图像传递给这样的方法
// Code from: http://discussions.apple.com/thread.jspa?messageID=7949889
- (UIImage *)scaleAndRotateImage:(UIImage *)image {
int kMaxResolution = 640; // Or whatever
CGImageRef imgRef = image.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
if (width > kMaxResolution || height > kMaxResolution) {
CGFloat ratio = width/height;
if (ratio > 1) {
bounds.size.width = kMaxResolution;
bounds.size.height = roundf(bounds.size.width / ratio);
}
else {
bounds.size.height = kMaxResolution;
bounds.size.width = roundf(bounds.size.height * ratio);
}
}
CGFloat scaleRatio = bounds.size.width / width;
CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
CGFloat boundHeight;
UIImageOrientation orient = image.imageOrientation;
switch(orient) {
case UIImageOrientationUp: //EXIF = 1
transform = CGAffineTransformIdentity;
break;
case UIImageOrientationUpMirrored: //EXIF = 2
transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
break;
case UIImageOrientationDown: //EXIF = 3
transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationDownMirrored: //EXIF = 4
transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
break;
case UIImageOrientationLeftMirrored: //EXIF = 5
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeft: //EXIF = 6
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRightMirrored: //EXIF = 7
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
case UIImageOrientationRight: //EXIF = 8
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
default:
[NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];
}
UIGraphicsBeginImageContext(bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
CGContextScaleCTM(context, -scaleRatio, scaleRatio);
CGContextTranslateCTM(context, -height, 0);
}
else {
CGContextScaleCTM(context, scaleRatio, -scaleRatio);
CGContextTranslateCTM(context, 0, -height);
}
CGContextConcatCTM(context, transform);
CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height), imgRef);
UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return imageCopy;
}
于 2013-08-02T12:44:47.193 回答