iOS学习：调用相机，选择图片上传，带预览功能

一、新建工程





二、拖控件，创建映射





三、在.h中加入delegate

@interface ViewController : UIViewController

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四、实现按钮事件

-(IBAction)chooseImage:(id)sender {

UIActionSheet *sheet;

// 判断是否支持相机

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])

{

sheet = [[UIActionSheet alloc] initWithTitle:@"选择" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"拍照",@"从相册选择", nil];

}

else {

sheet = [[UIActionSheet alloc] initWithTitle:@"选择" delegate:self cancelButtonTitle:nil destructiveButtonTitle:@"取消" otherButtonTitles:@"从相册选择", nil];

}

sheet.tag = 255;

[sheet showInView:self.view];

}

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五、实现actionSheet delegate事件

-(void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex

{

if (actionSheet.tag == 255) {

NSUInteger sourceType = 0;

// 判断是否支持相机

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

switch (buttonIndex) {

case 0:

// 取消

return;

case 1:

// 相机

sourceType = UIImagePickerControllerSourceTypeCamera;

break;

case 2:

// 相册

sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

break;

}

}

else {

if (buttonIndex == 0) {

return;

} else {

sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

}

}

// 跳转到相机或相册页面

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、实现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];

/* 此处info 有六个值

* UIImagePickerControllerMediaType; // an NSString UTTypeImage)

* UIImagePickerControllerOriginalImage; // a UIImage 原始图片

* UIImagePickerControllerEditedImage; // a UIImage 裁剪后图片

* 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

*/

// 保存图片至本地，方法见下文

[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、保存图片

高保真压缩图片方法

NSData * UIImageJPEGRepresentation ( UIImage *image, CGFloat compressionQuality

)

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此方法可将图片压缩，但是图片质量基本不变，第二个参数即图片质量参数。

#pragma mark - 保存图片至沙盒

- (void) saveImage:(UIImage *)currentImage withName:(NSString *)imageName

{

NSData *imageData = UIImageJPEGRepresentation(currentImage, 0.5);

// 获取沙盒目录

NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:imageName];

// 将图片写入文件

[imageData writeToFile:fullPath atomically:NO];

}

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八、实现点击图片预览功能，滑动放大缩小，带动画

-(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 就是触点的坐标

// 触点在imageView内，点击imageView时 放大,再次点击时缩小

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)

{

// 设置图片放大动画

[UIView beginAnimations:nil context:nil];

// 动画时间

[UIView setAnimationDuration:1];

if (isFullScreen) {

// 放大尺寸

self.imageView.frame = CGRectMake(0, 0, 320, 480);

}

else {

// 缩小尺寸

self.imageView.frame = CGRectMake(50, 65, 90, 115);

}

// commit动画

[UIView commitAnimations];

}

}

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九、上传图片，使用ASIhttpRequest类库实现，由于本文重点不是网络请求，故不对ASIHttpRequest详细讲述，只贴出部分代码

ASIFormDataRequest *requestReport = [[ASIFormDataRequest alloc] initWithURL:服务器地址];

NSString *Path = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImage.png"];

[requestReport setFile:Path forKey:@"picturepath"];

[requestReport buildPostBody];

requestReport.delegate = self;

[requestReport startAsynchronous];

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效果图如下：





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ps：

1.模拟器无法调用相机；

2.模拟器添加图片方法：将图片拖至模拟器主屏，会由模拟器safari打开，长按可保存至模拟器相册，即可进行模拟器调试了。

3.关于调用相机，是系统自带的，不知道如何修改英文标题为中文，如cancel换为取消等，望知道的大虾们不吝告知，万分感谢

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