ios圖片操作

先看UIImagePickerControllerDelegate的協定，主要是利用iOS內建的圖片選取控制器

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

取得照片後的處理，範例

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

{

UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];//

UIImage *cmpImg = [appDelegate scaleImage:image toScale:kImageScaleRate];//縮圖

NSData *blobImage = UIImageJPEGRepresentation(cmpImg, kImageCompressRate);//圖片壓縮為NSData

[self dismissModalViewControllerAnimated:YES];

[self updateImage:blobImage withIndexPath:indexPath_];//更新圖片(自定義函數)

}

叫起圖片選取器

-(void)snapImage:(id)sender

{

UIImagePickerController *ipc = [[UIImagePickerController alloc]init];

ipc.sourceType = UIImagePickerControllerSourceTypeCamera;//圖片來源

ipc.videoQuality = UIImagePickerControllerQualityTypeLow;

ipc.delegate = self;

ipc.allowsEditing = NO;

[self presentModalViewController:ipc animated:YES];

}

縮圖函數(自定義)

- (UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize

{

UIGraphicsBeginImageContext(CGSizeMake(image.size.width*scaleSize,image.size.height*scaleSize));

[image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height *scaleSize)];

UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return scaledImage;

}

儲存至資料庫※圖片傳入時已是NSData

-(void)updateImage:(NSData*)image withIndexPath:(NSIndexPath*)indexPath

{

NSDateFormatter *dateformat = [[NSDateFormatter alloc]init];

[dateformat setDateFormat:@"YYYY-MM-dd HH:mm:ss"];

NSDate* spentDate = [(SpentMoney*)[dailyContent objectAtIndex:indexPath.row] spentDate];

NSString *date = [NSString stringWithString:[dateformat stringFromDate: spentDate]];

//圖片傳入的時候，已經是NSData了，所以只要單純寫入即可

BOOL sucess = [fmdb executeUpdate:@"update spentMoney set contentImage =? where spentDate=?",image, date];

if (!sucess) {

[appDelegate showMessageWith:@"fail to insert image" andMessage:nil];

}

dateformat = nil;

[self fetchData];

}

自資料庫讀取，範例是tableView的Cell資料呈現的內容，看紅色字部份

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

 

if (cell==nil) {

cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];

}

cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;

SpentMoney *spentMoney = [dailyContent objectAtIndex:indexPath.row];

NSDateFormatter *dateformat = [[NSDateFormatter alloc]init];

dateformat.dateFormat = @"HH:mm:ss";

cell.textLabel.text = [dateformat stringFromDate: spentMoney.spentDate];

cell.detailTextLabel.text =  [NSString stringWithFormat:@"$%@",spentMoney.money];

//圖片存至資料庫時是用NSData，讀取也只要用imageWithData把圖片讀取出來

cell.imageView.image = [UIImage imageWithData:spentMoney.contentImage];

return cell;

dateformat = nil;

}

//add another author's passage

使用UIImagePickerController打開圖片庫和相機選擇圖片修改頭像的主要方法如下，

聲明：這個是iphone版本的，ipad版本的使用這個不行，因爲iPad要用UIPopover纔可以。

效果圖：

- (void)viewDidLoad
{
    [super viewDidLoad];
    //獲取Documents文件夾目錄
    NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentPath = [path objectAtIndex:0];
    //指定新建文件夾路徑
    NSString *imageDocPath = [documentPath stringByAppendingPathComponent:@"ImageFile"];
    //創建ImageFile文件夾
    [[NSFileManager defaultManager] createDirectoryAtPath:imageDocPath withIntermediateDirectories:YES attributes:nil error:nil];
    //保存圖片的路徑
    self.imagePath = [imageDocPath stringByAppendingPathComponent:@"image.png"];

}

-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:YES];
    //根據圖片路徑載入圖片
    UIImage *image=[UIImage imageWithContentsOfFile:self.imagePath];
    if (image == nil) {
        //顯示默認
        [changeImg setBackgroundImage:[UIImage imageNamed:@"[email protected]"] forState:UIControlStateNormal];
    }else {
        //顯示保存過的
        [changeImg setBackgroundImage:image forState:UIControlStateNormal];
    }
}

- (void)dealloc {
    [imagePath release];
    [changeImg release];
    [super dealloc];
}
- (IBAction)changeImage:(id)sender {
    UIActionSheet *myActionSheet = [[UIActionSheet alloc]
                                    initWithTitle:nil
                                    delegate:self
                                    cancelButtonTitle:@"取消"
                                    destructiveButtonTitle:nil
                                    otherButtonTitles: @"從相冊選擇", @"拍照",nil];
    [myActionSheet showInView:self.view];
    [myActionSheet release];
}
-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{
    switch (buttonIndex) {
        case 0:
            //從相冊選擇
            [self LocalPhoto];
            break;
        case 1:
            //拍照
            [self takePhoto];
            break;
        default:
            break;
    }
}
//從相冊選擇
-(void)LocalPhoto{
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    //資源類型爲圖片庫
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    picker.delegate = self;
    //設置選擇後的圖片可被編輯
    picker.allowsEditing = YES;
    [self presentModalViewController:picker animated:YES];
    [picker release];
}

//拍照
-(void)takePhoto{
    //資源類型爲照相機
    UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
    //判斷是否有相機
    if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]){
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        //設置拍照後的圖片可被編輯
        picker.allowsEditing = YES;
        //資源類型爲照相機
        picker.sourceType = sourceType;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }else {
        NSLog(@"該設備無攝像頭");
    }
}
#pragma Delegate method UIImagePickerControllerDelegate
//圖像選取器的委託方法，選完圖片後回調該方法
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo{

    //當圖片不爲空時顯示圖片並保存圖片
    if (image != nil) {
        //圖片顯示在界面上
        [changeImg setBackgroundImage:image forState:UIControlStateNormal];

        //以下是保存文件到沙盒路徑下
        //把圖片轉成NSData類型的數據來保存文件
        NSData *data;
        //判斷圖片是不是png格式的文件
        if (UIImagePNGRepresentation(image)) {
            //返回爲png圖像。
            data = UIImagePNGRepresentation(image);
        }else {
            //返回爲JPEG圖像。
            data = UIImageJPEGRepresentation(image, 1.0);
        }
        //保存
        [[NSFileManager defaultManager] createFileAtPath:self.imagePath contents:data attributes:nil];

    }
    //關閉相冊界面
    [picker dismissModalViewControllerAnimated:YES];
}