在目标c中调用c ++类 [英] call c++ class within objective c one
问题描述
我写了c ++类返回uiimage（我确保它不返回null），我试图从目标c obe（基于uiview的类）调用如下代码，问题是没有图像显示任何建议要解决的，也是当把c ++类的代码放在目标c类时，图像出现
images imaging = new images（）; // c ++ class .mm文件
NSArray * paths = NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，
NSUserDomainMask，
是）;
NSString * fullPath = [[paths lastObject] stringByAppendingPathComponent：ImageFileName];
NSLog（fullPath）;
@try {
UIView * holderView = [[UIView alloc] initWithFrame：CGRectMake（0,0，self.view.bounds.size.width，self.view。 bounds.size.height）];
viewer = [[UIImageView alloc] initWithFrame：[holderView frame]];
[viewer setImage：imaging-> LoadImage（fullPath）];
viewer.contentMode = UIViewContentModeScaleAspectFit;
//holderView.contentMode = UIViewContentModeScaleAspectFit;
[holderView addSubview：viewer];
[self.view addSubview：holderView];
}
@catch（NSException * e）{
NSLog（@这是发生了什么：％a，e）;
}
这是loadimage的一部分， / p>
试试{
...............
CGDataProviderRef provider = CGDataProviderCreateWithData（NULL，MyFilter-> GetOutput（） - > GetBufferPointer（），bufferLength，NULL）;
if（colorSpaceRef == NULL）
{
NSLog（@分配颜色空间错误）;
CGDataProviderRelease（provider）;
}
CGImageRef iref = CGImageCreate（Width，Height，bitsPerComponent，bitsPerPixel，bytesPerRow，colorSpaceRef，bitmapInfo， NULL，YES，renderIntent）;
CGContextRef context = NULL;
if（（Comptype == itk :: ImageIOBase :: SHORT）||（Comptype == itk :: ImageIOBase :: USHORT））
{
context = CGBitmapContextCreate MyFilter-> GetOutput（） - > GetBufferPointer（），
Width，
Height，
bitsPerComponent，
bytesPerRow，
colorSpaceRef，
bitmapInfo） ;
}
else
{
context = CGBitmapContextCreate（myimg-> GetBufferPointer（），
Width，
Height，
bitsPerComponent，
bytesPerRow，
colorSpaceRef，
bitmapInfo）;
}
if（context == NULL）
{
NSLog（@错误上下文未创建）;
}
//创建要显示的UIImage
UIImage * uiimage = nil;
if（context）
{
CGContextDrawImage（context，CGRectMake（0.0f，0.0f，Width，Height），iref）;
CGImageRef imageRef = CGBitmapContextCreateImage（context）;
// if（[UIImage respondingToSelector：@selector（imageWithCGImage：scale：orientation :)]）{
// float scale = [[UIScreen mainScreen] scale];
// uiimage = [UIImage imageWithCGImage：imageRef scale：scale orientation：UIImageOrientationUp];
//} else {
uiimage = [UIImage imageWithCGImage：imageRef];
//}
CGImageRelease（imageRef）;
CGContextRelease（context）;
}
CGColorSpaceRelease（colorSpaceRef）;
CGImageRelease（iref）;
CGDataProviderRelease（provider）;
return uiimage;
// return uiimage;
}
catch（itk :: ExceptionObject& e）
{
throw
}
在Cocoa中由类函数创建的Obj-C对象被自动释放。您可能需要：
uiimage = [UIImage imageWithCGImage：imageRef];
[uiimage retain];
因为这是在iOS上我相信这是必需的，因为iOS没有垃圾收集像OS X可可。
I wrote c++ class that return uiimage (I made sure that it doesn't return null) and I am trying to call it from objective c obe (uiview based classs) as below code, the problem is that no image be displayed any suggestion to solve that , also when put the code of c++ class at the objective c class the image appear
images imaging = new images(); // the c++ class .mm file
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,
YES);
NSString *fullPath = [[paths lastObject] stringByAppendingPathComponent:ImageFileName];
NSLog(fullPath);
@try {
UIView* holderView = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.bounds.size.width,self.view.bounds.size.height)];
viewer = [[UIImageView alloc] initWithFrame:[holderView frame]];
[viewer setImage:imaging->LoadImage(fullPath)];
viewer.contentMode = UIViewContentModeScaleAspectFit;
//holderView.contentMode = UIViewContentModeScaleAspectFit ;
[holderView addSubview:viewer];
[self.view addSubview:holderView];
}
@catch (NSException * e) {
NSLog(@"this was what happened: %a ",e);
}
this is a part of the loadimage, which create image from the buffer data
try{ ...............
CGDataProviderRef provider = CGDataProviderCreateWithData(NULL,MyFilter->GetOutput()->GetBufferPointer(), bufferLength, NULL); if(colorSpaceRef == NULL) { NSLog(@"Error allocating color space"); CGDataProviderRelease(provider); }
CGImageRef iref = CGImageCreate(Width,Height,bitsPerComponent,bitsPerPixel,bytesPerRow, colorSpaceRef,bitmapInfo,provider,NULL,YES,renderingIntent);
CGContextRef context = NULL;
if ((Comptype==itk::ImageIOBase::SHORT)||(Comptype==itk::ImageIOBase::USHORT))
{
context = CGBitmapContextCreate(MyFilter->GetOutput()->GetBufferPointer(),
Width,
Height,
bitsPerComponent,
bytesPerRow,
colorSpaceRef,
bitmapInfo);
}
else
{
context = CGBitmapContextCreate(myimg->GetBufferPointer(),
Width,
Height,
bitsPerComponent,
bytesPerRow,
colorSpaceRef,
bitmapInfo);
}
if(context == NULL)
{
NSLog(@"Error context not created");
}
//Create the UIImage to be displayed
UIImage * uiimage = nil;
if (context)
{
CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, Width, Height), iref);
CGImageRef imageRef = CGBitmapContextCreateImage(context);
//if([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)]) {
//float scale = [[UIScreen mainScreen] scale];
//uiimage = [UIImage imageWithCGImage:imageRef scale:scale orientation:UIImageOrientationUp];
//} else {
uiimage = [UIImage imageWithCGImage:imageRef];
//}
CGImageRelease(imageRef);
CGContextRelease(context);
}
CGColorSpaceRelease(colorSpaceRef);
CGImageRelease(iref);
CGDataProviderRelease(provider);
return uiimage;
//return uiimage;
}
catch (itk::ExceptionObject & e)
{
throw(e);
}
Sometimes the Obj-C objects created by class functions in Cocoa are autoreleased. You may need to do:
uiimage = [UIImage imageWithCGImage:imageRef];
[uiimage retain];
Since this is on iOS I believe this is required, since iOS does not have garbage collection like OS X Cocoa.
这篇关于在目标c中调用c ++类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
