提到从摄像头/相册获取图片是面向终端用户的，由用户去浏览并选择图片为程序使用。在这里，我们需要过UIImagePickerController类来和用户交互。
使用UIImagePickerController和用户交互，我们需要实现2个协议<UIImagePickerControllerDelegate,UINavigationControllerDelegate>。
View Code
代码如下 复制代码
pragma mark 从用户相册获取活动图片
- (void)pickImageFromAlbum
{ imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate =self; imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical; imagePicker.allowsEditing =YES;
[self presentModalViewController:imagePicker animated:YES];
}
我们来看看上面的从相册获取图片，我们首先要实例化UIImagePickerController对象，然后设置imagePicker对象为当前对象，设置imagePicker的图片来源为UIImagePickerControllerSourceTypePhotoLibrary，表明当前图片的来源为相册，除此之外还可以设置用户对图片是否可编辑。
View Code
代码如下 复制代码
pragma mark 从摄像头获取活动图片
- (void)pickImageFromCamera
{
imagePicker = [[UIImagePickerController alloc] init]; imagePicker.delegate =self; imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera; imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical; imagePicker.allowsEditing =YES;
[self presentModalViewController:imagePicker animated:YES];
}
//打开相机
-
(IBAction)touch_photo:(id)sender {
// for iphone
UIImagePickerController *pickerImage = [[UIImagePickerController alloc] init];
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
pickerImage.sourceType = UIImagePickerControllerSourceTypeCamera;
pickerImage.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:pickerImage.sourceType];}
pickerImage.delegate =self;
pickerImage.allowsEditing =YES;//自定义照片样式
[self presentViewController:pickerImage animated:YES completion:nil];
}
以上是从摄像头获取图片，和从相册获取图片只是图片来源的设置不一样，摄像头图片的来源为UIImagePickerControllerSourceTypeCamera。
在和用户交互之后，用户选择好图片后，会回调选择结束的方法。
-(void)imagePickerController:(UIImagePickerController)picker didFinishPickingMediaWithInfo:(NSDictionary)info
{
//初始化imageNew为从相机中获得的--
UIImage imageNew = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
//设置image的尺寸
CGSize imagesize = imageNew.size;
imagesize.height =626;
imagesize.width =413;
//对图片大小进行压缩--
imageNew = [self imageWithImage:imageNew scaledToSize:imagesize];
NSData imageData = UIImageJPEGRepresentation(imageNew,0.00001);
if(m_selectImage==nil)
{
m_selectImage = [UIImage imageWithData:imageData];
NSLog(@"m_selectImage:%@",m_selectImage);
[self.TakePhotoBtn setImage:m_selectImage forState:UIControlStateNormal];
[picker dismissModalViewControllerAnimated:YES];
return ;
}
[picker release];
}
//对图片尺寸进行压缩--
-(UIImage)imageWithImage:(UIImage)image scaledToSize:(CGSize)newSize
{
// Create a graphics image context
UIGraphicsBeginImageContext(newSize);// Tell the old image to draw in this new context, with the desired
// new size
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];// Get the new image from the context
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();// End the context
UIGraphicsEndImageContext();// Return the new image.
return newImage;
}
图片保存到本地document里面--以及图片格式的转换
IOS开发之保存图片到Documents目录及PNG，JPEG格式相互转换 -
(void)imagePickerController:(UIImagePickerController )picker didFinishPickingMediaWithInfo:(NSDictionary)info {
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
if ([mediaType isEqualToString:@"public.image"]){
image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data;
if (UIImagePNGRepresentation(image) == nil) {
data = UIImageJPEGRepresentation(image, 1);
} else {
data = UIImagePNGRepresentation(image);
}NSFileManager *fileManager = [NSFileManager defaultManager]; NSString *filePath = [NSString stringWithString:[self getPath:@"image1"]]; //将图片存储到本地documents [fileManager createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:nil]; [fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.png"] contents:dataattributes:nil]; UIImage *editedImage = [[UIImage alloc] init]; editedImage = image; CGRect rect = CGRectMake(0, 0, 64, 96); UIGraphicsBeginImageContext(rect.size); [editedImage drawInRect:rect]; editedImage = UIGraphicsGetImageFromCurrentImageContext(); UIButton *imageButton = [UIButton buttonWithType:UIButtonTypeCustom]; imageButton.frame = CGRectMake(10, 10, 64, 96); [imageButton setImage:editedImage forState:UIControlStateNormal]; [self.view addSubview:imageButton]; [imageButton addTarget:self action:@selector(imageAction:)forControlEvents:UIControlEventTouchUpInside]; [ipc dismissModalViewControllerAnimated:YES];} else {
NSLog(@"MEdia");
}
上面的代码是当从相册里面选取图片之后保存到本地程序沙盒，在上面我们得到的图片中不能够得到图片名字，
以及不清楚图片格式，所以这个时候我们需要将其转换成NSdata二进制存储，
image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data;
if (UIImagePNGRepresentation(image) == nil) {
data = UIImageJPEGRepresentation(image, 1);
} else {
data = UIImagePNGRepresentation(image);
}
UIImagePNGRepresentation转换PNG格式的图片为二进制，如果图片的格式为JPEG则返回nil；
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.png"] contents:data attributes:nil]; 将图片保存为PNG格式
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.jpg"] contents:data attributes:nil]; 将图片保存为JPEG格式
我们也可以写成下面的格式存储图片
NSString *pngImage = [filePath stringByAppendingPathComponent:@"Documents/image.png"];
NSString *jpgImage = [filePath stringByAppendingPathComponent:@"Documents/image.jpg"];
[data writeToFile:pngImage atomically:YES];
[data writeToFile:jpgImage atomically:YES];提到从摄像头/相册获取图片是面向终端用户的，由用户去浏览并选择图片为程序使用。在这里，我们需要过UIImagePickerController类来和用户交互。
使用UIImagePickerController和用户交互，我们需要实现2个协议<UIImagePickerControllerDelegate,UINavigationControllerDelegate>。
View Code
代码如下 复制代码
pragma mark 从用户相册获取活动图片
-
(void)pickImageFromAlbum
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate =self;
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
imagePicker.allowsEditing =YES;[self presentModalViewController:imagePicker animated:YES];
}
我们来看看上面的从相册获取图片，我们首先要实例化UIImagePickerController对象，然后设置imagePicker对象为当前对象，设置imagePicker的图片来源为UIImagePickerControllerSourceTypePhotoLibrary，表明当前图片的来源为相册，除此之外还可以设置用户对图片是否可编辑。
View Code
代码如下 复制代码
pragma mark 从摄像头获取活动图片
-
(void)pickImageFromCamera
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate =self;
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
imagePicker.allowsEditing =YES;[self presentModalViewController:imagePicker animated:YES];
}
//打开相机 -
(IBAction)touch_photo:(id)sender {
// for iphone
UIImagePickerController *pickerImage = [[UIImagePickerController alloc] init];
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
pickerImage.sourceType = UIImagePickerControllerSourceTypeCamera;
pickerImage.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:pickerImage.sourceType];}
pickerImage.delegate =self;
pickerImage.allowsEditing =YES;//自定义照片样式
[self presentViewController:pickerImage animated:YES completion:nil];
}
以上是从摄像头获取图片，和从相册获取图片只是图片来源的设置不一样，摄像头图片的来源为UIImagePickerControllerSourceTypeCamera。
在和用户交互之后，用户选择好图片后，会回调选择结束的方法。
-(void)imagePickerController:(UIImagePickerController)picker didFinishPickingMediaWithInfo:(NSDictionary)info
{
//初始化imageNew为从相机中获得的--
UIImage imageNew = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
//设置image的尺寸
CGSize imagesize = imageNew.size;
imagesize.height =626;
imagesize.width =413;
//对图片大小进行压缩--
imageNew = [self imageWithImage:imageNew scaledToSize:imagesize];
NSData imageData = UIImageJPEGRepresentation(imageNew,0.00001);
if(m_selectImage==nil)
{
m_selectImage = [UIImage imageWithData:imageData];
NSLog(@"m_selectImage:%@",m_selectImage);
[self.TakePhotoBtn setImage:m_selectImage forState:UIControlStateNormal];
[picker dismissModalViewControllerAnimated:YES];
return ;
}
[picker release];
}
//对图片尺寸进行压缩--
-(UIImage)imageWithImage:(UIImage)image scaledToSize:(CGSize)newSize
{
// Create a graphics image context
UIGraphicsBeginImageContext(newSize);// Tell the old image to draw in this new context, with the desired
// new size
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];// Get the new image from the context
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();// End the context
UIGraphicsEndImageContext();// Return the new image.
return newImage;
}
图片保存到本地document里面--以及图片格式的转换
IOS开发之保存图片到Documents目录及PNG，JPEG格式相互转换 -
(void)imagePickerController:(UIImagePickerController )picker didFinishPickingMediaWithInfo:(NSDictionary)info {
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
if ([mediaType isEqualToString:@"public.image"]){
image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data;
if (UIImagePNGRepresentation(image) == nil) {
data = UIImageJPEGRepresentation(image, 1);
} else {
data = UIImagePNGRepresentation(image);
}NSFileManager *fileManager = [NSFileManager defaultManager]; NSString *filePath = [NSString stringWithString:[self getPath:@"image1"]]; //将图片存储到本地documents [fileManager createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:nil]; [fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.png"] contents:dataattributes:nil]; UIImage *editedImage = [[UIImage alloc] init]; editedImage = image; CGRect rect = CGRectMake(0, 0, 64, 96); UIGraphicsBeginImageContext(rect.size); [editedImage drawInRect:rect]; editedImage = UIGraphicsGetImageFromCurrentImageContext(); UIButton *imageButton = [UIButton buttonWithType:UIButtonTypeCustom]; imageButton.frame = CGRectMake(10, 10, 64, 96); [imageButton setImage:editedImage forState:UIControlStateNormal]; [self.view addSubview:imageButton]; [imageButton addTarget:self action:@selector(imageAction:)forControlEvents:UIControlEventTouchUpInside]; [ipc dismissModalViewControllerAnimated:YES];} else {
NSLog(@"MEdia");
}
上面的代码是当从相册里面选取图片之后保存到本地程序沙盒，在上面我们得到的图片中不能够得到图片名字，
以及不清楚图片格式，所以这个时候我们需要将其转换成NSdata二进制存储，
image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data;
if (UIImagePNGRepresentation(image) == nil) {
data = UIImageJPEGRepresentation(image, 1);
} else {
data = UIImagePNGRepresentation(image);
}
UIImagePNGRepresentation转换PNG格式的图片为二进制，如果图片的格式为JPEG则返回nil；
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.png"] contents:data attributes:nil]; 将图片保存为PNG格式
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.jpg"] contents:data attributes:nil]; 将图片保存为JPEG格式
我们也可以写成下面的格式存储图片
NSString *pngImage = [filePath stringByAppendingPathComponent:@"Documents/image.png"];
NSString *jpgImage = [filePath stringByAppendingPathComponent:@"Documents/image.jpg"];
[data writeToFile:pngImage atomically:YES];
[data writeToFile:jpgImage atomically:YES];
