[英]How do I handle the actions of a UIAlertController?
How can I link UIAlertController alert action buttons with action handlers using objective-c? 如何使用objective-c将UIAlertController警报操作按钮与操作处理程序链接? I'm using Xcode 7.1. 我正在使用Xcode 7.1。
Here is my code: 这是我的代码:
- (IBAction)selectbtn:(UIButton *)sender {
UIAlertController *alert=[ UIAlertController alertControllerWithTitle:@"NEW" message:@"button pressed" preferredStyle:UIAlertControllerStyleActionSheet];
UIAlertAction *cameraaction=[UIAlertAction actionWithTitle:@"From camera" style:UIAlertActionStyleDefault handler:nil ];
[alert addAction:cameraaction];
UIAlertAction *libraryaction=[UIAlertAction actionWithTitle:@"From photo library" style:UIAlertActionStyleDefault handler:nil ];
[alert addAction:libraryaction];
UIAlertAction *cancelaction=[UIAlertAction actionWithTitle:@"cancel" style:UIAlertActionStyleDestructive handler:nil];
[alert addAction:cancelaction];
[self presentViewController:alert animated:YES
completion:nil];
}
Objective-C Objective-C的
UIAlertController works like this: UIAlertController的工作方式如下:
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Title" message:@"text mssg" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action){
// Ok action example
}];
UIAlertAction *otherAction = [UIAlertAction actionWithTitle:@"Other" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action){
// Other action
}];
[alert addAction:okAction];
[alert addAction:otherAction];
[self presentViewController:alert animated:YES completion:nil];
I think you meant that. 我想你的意思是。
Swift 3.0/4.0 Swift 3.0 / 4.0
let myalert = UIAlertController(title: "Titulo mensaje", message: "Mi mensaje.", preferredStyle: UIAlertControllerStyle.alert)
myalert.addAction(UIAlertAction(title: "Aceptar", style: .default) { (action:UIAlertAction!) in
print("Selected")
})
myalert.addAction(UIAlertAction(title: "Cancelar", style: .cancel) { (action:UIAlertAction!) in
print("Cancel")
})
self.present(myalert, animated: true)
You can add any code you want in the handler of the action method, sample code can be like this: 您可以在action方法的处理程序中添加所需的任何代码,示例代码可以是这样的:
@interface ViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (strong, nonatomic) UIAlertController *alertCtrl;
@property (strong, nonatomic) UIImagePickerController *imagePicker;
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[self setupAlertCtrl];
}
- (void) setupAlertCtrl
{
self.alertCtrl = [UIAlertController alertControllerWithTitle:@"Select Image"
message:nil
preferredStyle:UIAlertControllerStyleActionSheet];
//Create an action
UIAlertAction *camera = [UIAlertAction actionWithTitle:@"From camera"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action)
{
[self handleCamera];
}];
UIAlertAction *imageGallery = [UIAlertAction actionWithTitle:@"From Photo Library"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action)
{
[self handleImageGallery];
}];
UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"Cancel"
style:UIAlertActionStyleCancel
handler:^(UIAlertAction *action)
{
[self dismissViewControllerAnimated:YES completion:nil];
}];
//Add action to alertCtrl
[self.alertCtrl addAction:camera];
[self.alertCtrl addAction:imageGallery];
[self.alertCtrl addAction:cancel];
}
- (IBAction)selectImagePressed:(UIButton *)sender
{
[self presentViewController:self.alertCtrl animated:YES completion:nil];
}
- (void)handleCamera
{
#if TARGET_IPHONE_SIMULATOR
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Error"
message:@"Camera is not available on simulator"
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action)
{
[self dismissViewControllerAnimated:YES completion:nil];
}];
[alert addAction:ok];
[self presentViewController:alert animated:YES completion:nil];
#elif TARGET_OS_IPHONE
//Some code for iPhone
self.imagePicker = [[UIImagePickerController alloc] init];
self.imagePicker.delegate = self;
self.imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:self.imagePicker animated:YES completion:nil];
#endif
}
- (void)handleImageGallery
{
self.imagePicker = [[UIImagePickerController alloc] init];
self.imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
self.imagePicker.delegate = self;
[self presentViewController:self.imagePicker animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSData *dataImage = UIImageJPEGRepresentation([info objectForKey:@"UIImagePickerControllerOriginalImage"],1);
UIImage *img = [[UIImage alloc] initWithData:dataImage];
[self.imageView setImage:img];
[self.imagePicker dismissViewControllerAnimated:YES completion:nil];
}
UIAlertView Controller with multiple textFields. 具有多个textField的UIAlertView控制器。
@IBAction func showAlert(_ sender: UIButton) {
let alert = UIAlertController(title: "Registration", message: "Enter your name!", preferredStyle: .alert)
alert.addTextField { (textField1: UITextField) in
textField1.placeholder = "John"
}
alert.addTextField { (textField2: UITextField) in
textField2.placeholder = "Doe"
}
alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction) in
if let textField1 = alert.textFields?.first {
if textField1.text == "" {
print("you have to enter something first")
}else {
print("Hello \(textField1.text!)")
}
}
if let textField2 = alert.textFields?.first {
if textField2.text == "" {
print("you have to enter something first")
}else {
print("Hello \(textField2.text!)")
}
}
}))
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(alert, animated: true, completion: nil)
}
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