相冊
iphone的相冊包含攝像頭膠卷+用戶計算機同步的部分照片。用戶可以通過UIImagePickerController類提供的交互對話框來從相冊中選擇圖像。但是，注意：相冊中的圖片機器路徑無法直接從應用程序訪問，只能通過終端用戶去選擇和使用相冊圖片
應用程序包
應用程序包可能會將圖像與可執行程序、Info.plist文件和其他資源一同存儲。我們可以通過本地文件路徑來讀取這些基於包的圖像並在應用程序中顯示它們。
沙盒
借助沙盒，我們可以把圖片存儲到Documents、Library、tmp文件夾中。這些文件均可有應用程序讀取，且可以通過文件路徑創建圖像。盡管沙盒外的部分從技術上說是可行的，但是apple表明這些部分不在appstore應用程序允許訪問的范圍之內。
Internet
應用程序可以通過圖片的URL來訪問Internet上的資源。
以上為一些小知識，來自《iphone開發秘籍(第二版)》，可以自己去參考此書。
下面開始切入正題，從攝像頭/相冊獲取圖片，壓縮圖片，上傳圖片。
從攝像頭/相冊獲取圖片
剛剛在上面的知識中提到從攝像頭/相冊獲取圖片是面向終端用戶的，由用戶去瀏覽並選擇圖片為程序使用。在這里，我們需要過UIImagePickerController類來和用戶交互。
使用UIImagePickerController和用戶交互，我們需要實現2個協議。
View Code
代碼如下
#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，我們首先要實例化UIImagePickerController對象，然后設置imagePicker對象為當前對象，設置imagePicker的圖片來源為UIImagePickerControllerSourceTypePhotoLibrary，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。
View Code
代碼如下
#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];
}
以上是從攝像頭獲取圖片，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，用戶選擇好圖片后，會回調選擇結束的方法。
View Code
代碼如下
- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
UIImage *image= [info objectForKey:@"UIImagePickerControllerOriginalImage"];
if (picker.sourceType == UIImagePickerControllerSourceTypeCamera)
{
// UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
}
theImage = [UtilMethod imageWithImageSimple:image scaledToSize:CGSizeMake(120.0, 120.0)];
UIImage *midImage = [UtilMethod imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];
UIImage *bigImage = [UtilMethod imageWithImageSimple:image scaledToSize:CGSizeMake(440.0, 440.0)];
[theImage retain];
[self saveImage:theImage WithName:@"salesImageSmall.jpg"];
[self saveImage:midImage WithName:@"salesImageMid.jpg"];
[self saveImage:bigImage WithName:@"salesImageBig.jpg"];
[self dismissModalViewControllerAnimated:YES];
[self refreshData];
[picker release];
}
在回調結束的方法中，我們對圖片進行了大小的處理，為圖片的上傳做准備。
縮放圖片
縮放圖片比較簡單，就直接放上代碼，讓大家參考一下。
View Code
代碼如下
//壓縮圖片
+ (UIImage*)imageWithImageSimple:(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;
}
存儲圖像
在上面我們獲取到了圖片並對圖片進行了壓縮，通過之前的小知識了解到，將應用需要的一些圖片存入沙盒是個不錯的選擇，而且應用程序可以直接通過路徑去方法沙盒中的圖片，在這里我們將圖片存入沙盒中的Documents目錄下。
View Code
代碼如下
#pragma mark 保存圖片到document
- (void)saveImage:(UIImage *)tempImage WithName:(NSString *)imageName
{
NSData* imageData = UIImagePNGRepresentation(tempImage);
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
// Now we get the full path to the file
NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName];
// and then we write it out
[imageData writeToFile:fullPathToFile atomically:NO];
}
從Documents目錄下獲取圖片
要從Documents下面獲取圖片，我們首先需要獲取Documents目錄的路徑。
View Code
代碼如下
#pragma mark 從文檔目錄下獲取Documents路徑
- (NSString *)documentFolderPath
{
return [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
}
然后，我們便可以通過文件名，去訪問獲取資源了。
View Code
上傳圖片
項目中我們使用了ASIFormHttpRequest的開源框架，http請求的部分代碼如下，http返回以及相關回調方法略去。
View Code
代碼如下
- (void)upLoadSalesBigImage:(NSString *)bigImage MidImage:(NSString *)midImage SmallImage:(NSString *)smallImage
{
NSURL *url = [NSURL URLWithString:UPLOAD_SERVER_URL];
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
[request setPostValue:@"photo" forKey:@"type"];
[request setFile:bigImage forKey:@"file_pic_big"];
[request buildPostBody];
[request setDelegate:self];
[request setTimeOutSeconds:TIME_OUT_SECONDS];
[request startAsynchronous];
}
從UIWebView中調用iOS相冊，並選擇圖片上傳到Linux Web服務器。
(2012-08-09 17:03:29)
//
// ViewController.h
// Xcode_FileUpload
//
// Created by KirSsu Ryu on 12-8-7.
// Copyright (c) 2012年 __JModule__. All rights reserved.
//
#import
//UIWebViewDelegate 代理類：跟javascript相互傳值。
//UINavigationControllerDelegate,UIImagePickerControllerDelegate 代理類：打開相冊等一系列操作。
@interface ViewController : UIViewController<</SPAN>UIWebViewDelegate,UINavigationControllerDelegate,UIImagePickerControllerDelegate>{
UIWebView *myWebView;
UIImagePickerController *picker_library_;
}
//我的WebView控件
@property (nonatomic, retain) IBOutlet UIWebView *myWebView;
//相冊類的變量
@property (nonatomic, retain) IBOutlet UIImagePickerController *picker_library_;
@end
//
// ViewController.h
// Xcode_FileUpload
//
// Created by KirSsu Ryu on 12-8-7.
// Copyright (c) 2012年 __JModule__. All rights reserved.
//
#import "ViewController.h"
@interface ViewController()
@end
@implementation ViewController
@synthesize myWebView;
@synthesize picker_library_;
- (void)viewDidLoad
{
[super viewDidLoad];
//代理UIWebViewDelegate
myWebView.delegate = self;
//設置要載入的鏈接
NSURL *url = [NSURL URLWithString:@"http://＊＊＊＊＊/test/index.php"];
//創建一個請求對象
NSURLRequest *request = [NSURLRequest requestWithURL:url];
//把請求發送到webView里，實現顯示內容
[myWebView loadRequest:request];
}
- (void)viewDidUnload
{
[self setMyWebView:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
//獲得從網站得到的值
#pragma mark --
#pragma mark UIWebViewDelegate
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
//獲得請求的URL,第一次是路徑，當在web上點擊按鈕后獲得的是web穿過來的路徑。
NSString *requestString = [[request URL] absoluteString];
//根據":"拆分字符串，返回數組。
NSArray *components = [requestString componentsSeparatedByString:@":"];
//如果數組內的元素大於1並且第一個元素的值相等
if ([components count] > 1 && [(NSString *)[components objectAtIndex:0] isEqualToString:@"gallery"]) {
if([(NSString *)[components objectAtIndex:1] isEqualToString:@"open"])
{
[self openGallery];
}
return NO;
}
return YES;
}
//打開相冊
-(void)openGallery{
//初始化類
picker_library_ = [[UIImagePickerController alloc] init];
//指定幾總圖片來源
//UIImagePickerControllerSourceTypePhotoLibrary：表示顯示所有的照片。
//UIImagePickerControllerSourceTypeCamera：表示從攝像頭選取照片。
//UIImagePickerControllerSourceTypeSavedPhotosAlbum：表示僅僅從相冊中選取照片。
picker_library_.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
//表示用戶可編輯圖片。
picker_library_.allowsEditing = YES;
//代理
picker_library_.delegate = self;
[self presentModalViewController: picker_library_
animated: YES];
}
//3.x 用戶選中圖片后的回調
- (void)imagePickerController: (UIImagePickerController *)picker
didFinishPickingMediaWithInfo: (NSDictionary *)info
{
NSLog(@"3.x");
//獲得編輯過的圖片
UIImage* image = [info objectForKey: @"UIImagePickerControllerEditedImage"];
[self dismissModalViewControllerAnimated:YES];
[self imageUpload:image];
}
//2.x 用戶選中圖片之后的回調
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
NSLog(@"2.x");
NSMutableDictionary * dict= [NSMutableDictionary dictionaryWithDictionary:editingInfo];
[dict setObject:image forKey:@"UIImagePickerControllerEditedImage"];
//直接調用3.x的處理函數
[self imagePickerController:picker didFinishPickingMediaWithInfo:dict];
}
// 用戶選擇取消
- (void) imagePickerControllerDidCancel: (UIImagePickerController *)picker
{
[self dismissModalViewControllerAnimated:YES];
}
//上傳圖片方法
- (void) imageUpload:(UIImage *) image{
//把圖片轉換成imageDate格式
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
//傳送路徑
NSString *urlString = @"http://＊＊＊＊＊/test/upload.php";
//建立請求對象
NSMutableURLRequest * request = [[NSMutableURLRequest alloc] init];
//設置請求路徑
[request setURL:[NSURL URLWithString:urlString]];
//請求方式
[request setHTTPMethod:@"POST"];
//一連串上傳頭標簽
NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];
NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary]dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name="userfile"; filename="vim_go.jpg"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"]dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:imageData]];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary]dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];
//上傳文件開始
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
//獲得返回值
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
NSLog(@"%@",returnString);
}
@end