Ios 将UIImage转换为NSData并返回UIImage
我必须从数据库中填充表格单元格,并且图像在设备上。 我必须将该图像存储在Ios 将UIImage转换为NSData并返回UIImage,ios,uiimage,nsdata,Ios,Uiimage,Nsdata,我必须从数据库中填充表格单元格,并且图像在设备上。 我必须将该图像存储在imageDataObject中,如何将UIImage转换为NSData。 请建议,我尝试了许多解决方案,但没有将NSData转换回UIImage cell.textLabel.text = [[offlineImageListArray objectAtIndex:indexPath.row] imageName]; UIImage *thumbnail = [self retrieveImageFromD
imageDataObject
中,如何将UIImage
转换为NSData
。
请建议,我尝试了许多解决方案,但没有将NSData
转换回UIImage
cell.textLabel.text = [[offlineImageListArray objectAtIndex:indexPath.row] imageName];
UIImage *thumbnail = [self retrieveImageFromDevice:[[offlineImageListArray objectAtIndex:indexPath.row] imageName]];
NSData* data = ??????????;
ImageData *imageDataObject = [[ImageData alloc] initWithImageId:[[offlineImageListArray objectAtIndex:indexPath.row]imageId]
imageName:[[offlineImageListArray objectAtIndex:indexPath.row] imageName] imageData:data];
[imagesArray addObject:imageDataObject];
试试这个:
用于将UIImage
转换为NSData
NSData *imagedata = UIImagePNGRepresentation(thumbnail);
尝试将图像数据转换回UIImage
UIImage *image= [UIImage imageWithData:imagedata];
要将
UIImage
转换为NSData
,请使用uiimagejpegresentation(UIImage*image,CGFloat compressionQuality)
或UIImagePNGRepresentation(UIImage*image)
要将NSData
转换为UIImage
,请使用[UIImage-imageWithData:imageData]
因此,您的示例可以如下所示:
cell.textLabel.text = [[offlineImageListArray objectAtIndex:indexPath.row] imageName];
UIImage *thumbnail = [self retrieveImageFromDevice:[[offlineImageListArray objectAtIndex:indexPath.row] imageName]];
NSData* data = UIImagePNGRepresentation(thumbnail);
ImageData *imageDataObject = [[ImageData alloc] initWithImageId:[[offlineImageListArray objectAtIndex:indexPath.row]imageId] imageName:[[offlineImageListArray objectAtIndex:indexPath.row] imageName] imageData:data];
[imagesArray addObject:imageDataObject];
参考资料:
在Swift版本中:
let imageData = UIImagePNGRepresentation(image!)!
let imageFromData = UIImage(data: imageData)
使用if-let阻止数据以防止应用程序崩溃和代码的安全执行,因为函数uiImagePngResentation返回可选值
if let img = UIImage(named: "TestImage.png") {
if let data:Data = UIImagePNGRepresentation(img) {
// Handle operations with data here...
}
}
注:数据为Swift 3级。使用数据而不是NSData
斯威夫特3
通用图像操作(如png和jpg):
通过使用扩展名:
extension UIImage {
var pngRepresentationData: Data? {
return UIImagePNGRepresentation(img)
}
var jpegRepresentationData: Data? {
return UIImageJPEGRepresentation(self, 1.0)
}
}
*******
if let img = UIImage(named: "TestImage.png") { //UIImage(named: "TestImage.jpg")
if let data = img.pngRepresentationData {
handleOperationWithData(data: data)
} else if let data = img.jpegRepresentationData {
handleOperationWithData(data: data)
}
}
*******
func handleOperationWithData(data: Data) {
// Handle operations with data here...
if let image = UIImage(data: data) {
// Use image...
}
}
从图像转换数据:
extension UIImage {
var pngRepresentationData: Data? {
return UIImagePNGRepresentation(img)
}
var jpegRepresentationData: Data? {
return UIImageJPEGRepresentation(self, 1.0)
}
}
let data = myImage.jpegRepresentationData
let data1 = myImage.pngRepresentationData
let image = UIImage(data: data)
根据您的图像格式,尝试使用JPEG或PNG表示法:
UIImageJPEG表示法
以JPEG格式返回指定图像的数据
UIImagePNGRE演示文稿
以PNG格式返回指定图像的数据
示例:
extension UIImage {
var pngRepresentationData: Data? {
return UIImagePNGRepresentation(img)
}
var jpegRepresentationData: Data? {
return UIImageJPEGRepresentation(self, 1.0)
}
}
let data = myImage.jpegRepresentationData
let data1 = myImage.pngRepresentationData
let image = UIImage(data: data)
使用:
extension UIImage {
var pngRepresentationData: Data? {
return UIImagePNGRepresentation(img)
}
var jpegRepresentationData: Data? {
return UIImageJPEGRepresentation(self, 1.0)
}
}
let data = myImage.jpegRepresentationData
let data1 = myImage.pngRepresentationData
let image = UIImage(data: data)
从数据转换图像:
extension UIImage {
var pngRepresentationData: Data? {
return UIImagePNGRepresentation(img)
}
var jpegRepresentationData: Data? {
return UIImageJPEGRepresentation(self, 1.0)
}
}
let data = myImage.jpegRepresentationData
let data1 = myImage.pngRepresentationData
let image = UIImage(data: data)
可能的重复可能的重复如果我不知道图像表示是png还是jpg呢?如果我对jpg也使用
UIImagePNGRepresentation
会有问题吗?@János-这不会造成问题。我怎么知道UIImage是PNG?如果是JPEG呢?UIImage既不是jpg也不是png。这是一个原始位图。PNG和JPG是一种以较小格式传输图像的格式—简单、有效!谢谢