iOS學習：調用相機，選擇圖片上傳，帶預覽功能

一、新建工程

二、拖控件，創建映射

三、在.h中加入delegate

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四、實現按鈕事件

-(IBAction)chooseImage:(id)sender {
UIActionSheet *sheet;
// 判斷是否支持相機
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
sheet = [[UIActionSheet alloc] initWithTitle:@"選擇" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"拍照",@"從相冊選擇", nil];
}
else {
sheet = [[UIActionSheet alloc] initWithTitle:@"選擇" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"從相冊選擇", nil];
}
sheet.tag = 255;
[sheet showInView:self.view];
}

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五、實現actionSheet delegate事件

-(void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (actionSheet.tag == 255) {
NSUInteger sourceType = 0;
// 判斷是否支持相機
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
switch (buttonIndex) {
case 0:
// 取消
return;
case 1:
// 相機
sourceType = UIImagePickerControllerSourceTypeCamera;
break;
case 2:
// 相冊
sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
break;
}
}
else {
if (buttonIndex == 0) {
return;
} else {
sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
}
}
// 跳轉到相機或相冊頁面
UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.delegate = self;
imagePickerController.allowsEditing = YES;
imagePickerController.sourceType = sourceType;
[self presentViewController:imagePickerController animated:YES completion:^{}];
[imagePickerController release];
}
}

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六、實現ImagePicker delegate 事件

#pragma mark - image picker delegte
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[picker dismissViewControllerAnimated:YES completion:^{}];
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
/* 此處info 有六個值
* UIImagePickerControllerMediaType; // an NSString UTTypeImage)
* UIImagePickerControllerOriginalImage; // a UIImage 原始圖片
* UIImagePickerControllerEditedImage; // a UIImage 裁剪後圖片
* UIImagePickerControllerCropRect; // an NSValue (CGRect)
* UIImagePickerControllerMediaURL; // an NSURL
* UIImagePickerControllerReferenceURL // an NSURL that references an asset in the AssetsLibrary framework
* UIImagePickerControllerMediaMetadata // an NSDictionary containing metadata from a captured photo
*/
// 保存圖片至本地，方法見下文
[self saveImage:image withName:@"currentImage.png"];
NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImage.png"];
UIImage *savedImage = [[UIImage alloc] initWithContentsOfFile:fullPath];
isFullScreen = NO;
[self.imageView setImage:savedImage];
self.imageView.tag = 100;
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[self dismissViewControllerAnimated:YES completion:^{}];
}

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七、保存圖片
高保真壓縮圖片方法

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此方法可將圖片壓縮，但是圖片質量基本不變，第二個參數即圖片質量參數。

#pragma mark - 保存圖片至沙盒
- (void) saveImage:(UIImage *)currentImage withName:(NSString *)imageName
{
NSData *imageData = UIImageJPEGRepresentation(currentImage, 0.5);
// 獲取沙盒目錄
NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:imageName];
// 將圖片寫入文件
[imageData writeToFile:fullPath atomically:NO];
}

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八、實現點擊圖片預覽功能，滑動放大縮小，帶動畫

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
isFullScreen = !isFullScreen;
UITouch *touch = [touches anyObject];
CGPoint touchPoint = [touch locationInView:self.view];
CGPoint imagePoint = self.imageView.frame.origin;
//touchPoint.x ，touchPoint.y 就是觸點的座標
// 觸點在imageView內，點擊imageView時放大,再次點擊時縮小
if(imagePoint.x <= touchPoint.x && imagePoint.x +self.imageView.frame.size.width >=touchPoint.x && imagePoint.y <= touchPoint.y && imagePoint.y+self.imageView.frame.size.height >= touchPoint.y)
{
// 設置圖片放大動畫
[UIView beginAnimations:nil context:nil];
// 動畫時間
[UIView setAnimationDuration:1];
if (isFullScreen) {
// 放大尺寸
self.imageView.frame = CGRectMake(0, 0, 320, 480);
}
else {
// 縮小尺寸
self.imageView.frame = CGRectMake(50, 65, 90, 115);
}
// commit動畫
[UIView commitAnimations];
}
}

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九、上傳圖片，使用ASIhttpRequest類庫實現，由於本文重點不是網絡請求，故不對ASIHttpRequest詳細講述，只貼出部分代碼

ASIFormDataRequest *requestReport = [[ASIFormDataRequest alloc] initWithURL:服務器地址];
NSString *Path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImage.png"];
[requestReport setFile:Path forKey:@"picturepath"];
[requestReport buildPostBody];
requestReport.delegate = self;
[requestReport startAsynchronous];

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效果圖如下：

ps：
1.模擬器無法調用相機；
2.模擬器添加圖片方法：將圖片拖至模擬器主屏，會由模擬器safari打開，長按可保存至模擬器相冊，即可進行模擬器調試了。
3.關於調用相機，是系統自帶的，不知道如何修改英文標題爲中文，如cancel換爲取消等，望知道的大蝦們不吝告知，萬分感謝