ios硬件开发 照相机-图像选取器(UIImagePickerController)的用法
Posted on 2012-11-22 14:30 gavin.han 阅读(10683) 评论(1) 编辑 收藏 举报1.新建Empty Application,添加一个视图,设计xib如下:
2.使用 UIImagePickerController ,必须指定几个非常重要的属性:指定源的类型(指定之前要判断是否可用)、指定委托、指定图片是否可以编辑,设置完之后,就可以启动了,将其“推”出来即可。
- (IBAction)takeNewPhoto:(id)sender
{
//创建图片选择器
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
//指定源类型前,检查图片源是否可用
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
//指定源的类型
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
//在选定图片之前,用户可以简单编辑要选的图片。包括上下移动改变图片的选取范围,用手捏合动作改变图片的大小等。
imagePicker.allowsEditing = YES;
//实现委托,委托必须实现UIImagePickerControllerDelegate协议,来对用户在图片选取器中的动作
imagePicker.delegate = self;
//设置完iamgePicker后,就可以启动了。用以下方法将图像选取器的视图“推”出来
[self presentModalViewController:imagePicker animated:YES];
[imagePicker release];
}
else
{
UIAlertView *alert =[[UIAlertView alloc] initWithTitle:nil message:@"相机不能用" delegate:nil cancelButtonTitle:@"关闭" otherButtonTitles:nil];
[alert show];
[alert release];
}
}
//创建图片选择器
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
//指定源类型前,检查图片源是否可用
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
//指定源的类型
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
//在选定图片之前,用户可以简单编辑要选的图片。包括上下移动改变图片的选取范围,用手捏合动作改变图片的大小等。
imagePicker.allowsEditing = YES;
//实现委托,委托必须实现UIImagePickerControllerDelegate协议,来对用户在图片选取器中的动作
imagePicker.delegate = self;
//设置完iamgePicker后,就可以启动了。用以下方法将图像选取器的视图“推”出来
[self presentModalViewController:imagePicker animated:YES];
[imagePicker release];
}
else
{
UIAlertView *alert =[[UIAlertView alloc] initWithTitle:nil message:@"相机不能用" delegate:nil cancelButtonTitle:@"关闭" otherButtonTitles:nil];
[alert show];
[alert release];
}
}
3. UIImagePickerControllerDelegate协议的方法来实现对用户的操作
#pragma mark -
#pragma mark UIImagePickerControllerDelegate协议的方法
//用户点击图像选取器中的“cancel”按钮时被调用,这说明用户想要中止选取图像的操作
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[picker dismissModalViewControllerAnimated:YES];
}
//用户点击选取器中的“choose”按钮时被调用,告知委托对象,选取操作已经完成,同时将返回选取图片的实例
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
noticeLabel.hidden = YES;
[imageView setImage:image];
[picker dismissModalViewControllerAnimated:YES];
#pragma mark UIImagePickerControllerDelegate协议的方法
//用户点击图像选取器中的“cancel”按钮时被调用,这说明用户想要中止选取图像的操作
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[picker dismissModalViewControllerAnimated:YES];
}
//用户点击选取器中的“choose”按钮时被调用,告知委托对象,选取操作已经完成,同时将返回选取图片的实例
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
noticeLabel.hidden = YES;
[imageView setImage:image];
[picker dismissModalViewControllerAnimated:YES];
}
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