提到從攝像頭/相冊獲取圖片是面向終端用戶的形导，由用戶去瀏覽并選擇圖片為程序使用。在這里丝格，我們需要過UIImagePickerController類來和用戶交互算芯。使用UIImagePickerController和用戶交互，我們需要實現(xiàn)2個協(xié)議侥啤。
View Code
代碼如下復制代碼
#pragma mark 從用戶相冊獲取活動圖片
- (void)pickImageFromAlbum
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate =self;
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
imagePicker.allowsEditing =YES;
[self presentModalViewController:imagePicker animated:YES];
}
我們來看看上面的從相冊獲取圖片当叭，我們首先要實例化UIImagePickerController對象，然后設置imagePicker對象為當前對象盖灸，設置imagePicker的圖片來源為UIImagePickerControllerSourceTypePhotoLibrary蚁鳖，表明當前圖片的來源為相冊，除此之外還可以設置用戶對圖片是否可編輯赁炎。
View Code
代碼如下復制代碼
#pragma mark 從攝像頭獲取活動圖片
- (void)pickImageFromCamera
{
imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate =self;
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
imagePicker.allowsEditing =YES;
[self presentModalViewController:imagePicker animated:YES];
}
//打開相機
- (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;//自定義照片樣式
[self presentViewController:pickerImage animated:YES completion:nil];
}
以上是從攝像頭獲取圖片才睹，和從相冊獲取圖片只是圖片來源的設置不一樣，攝像頭圖片的來源為UIImagePickerControllerSourceTypeCamera。
在和用戶交互之后琅攘，用戶選擇好圖片后，會回調選擇結束的方法松邪。
-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{
//初始化imageNew為從相機中獲得的--
UIImage *imageNew = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
//設置image的尺寸
CGSize imagesize = imageNew.size;
imagesize.height =626;
imagesize.width =413;
//對圖片大小進行壓縮--
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];
}
//對圖片尺寸進行壓縮--
-(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;
}
圖片保存到本地document里面--以及圖片格式的轉換
IOS開發(fā)之保存圖片到Documents目錄及PNG坞琴，JPEG格式相互轉換
- (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"]];? ? ? ? //將圖片存儲到本地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");
}
上面的代碼是當從相冊里面選取圖片之后保存到本地程序沙盒，在上面我們得到的圖片中不能夠得到圖片名字逗抑，
以及不清楚圖片格式剧辐，所以這個時候我們需要將其轉換成NSdata二進制存儲，
image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data;
if (UIImagePNGRepresentation(image) == nil) {
data = UIImageJPEGRepresentation(image, 1);
} else {
data = UIImagePNGRepresentation(image);
}
UIImagePNGRepresentation轉換PNG格式的圖片為二進制，如果圖片的格式為JPEG則返回nil；
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.png"] contents:data attributes:nil];? ? 將圖片保存為PNG格式
[fileManager createFileAtPath:[filePath stringByAppendingString:@"/image.jpg"] contents:data attributes:nil];? 將圖片保存為JPEG格式
我們也可以寫成下面的格式存儲圖片
NSString *pngImage = [filePath stringByAppendingPathComponent:@"Documents/image.png"];
NSString *jpgImage = [filePath stringByAppendingPathComponent:@"Documents/image.jpg"];
[data writeToFile:pngImage atomically:YES];
[data writeToFile:jpgImage atomically:YES];
