根據按下哪個按鈕，使用UIImagePickerController更改正確按鈕的圖像

Question

這是問題： 我希望用戶點擊按鈕並選擇按鈕所代表的圖像。有不止一個按鈕，用戶可以選擇不同的圖像，或者他/她點擊的每個按鈕都選擇相同的圖像。 如何在void方法中添加一個if結構來檢查哪個按鈕被按下？

@implementation ViewController 
@synthesize tegelEen,tegelTwee; //tegelEen is a button an so is tegelTwee 

-(IBAction)Buttonclicked:(id)sender { 
    picController = [[UIImagePickerController alloc]init]; 
    picController.delegate = self; 
    picController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 

    [self presentViewController:picController animated:YES completion:nil]; 

} 



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

    UIImage *btnImage = [info objectForKey:UIImagePickerControllerOriginalImage]; 

     //Now it changes both buttons but I want it to change only the one that was clicked. 
     [tegelEen setImage:btnImage forState:UIControlStateNormal]; 
     [tegelTwee setImage:btnImage forState:UIControlStateNormal]; 

    [self dismissViewControllerAnimated:YES completion:nil]; 


} 

在此先感謝，是的，我對這種語言很新。

Answer 1

在-(IBAction)Buttonclicked:(id)sender，按鈕點擊是sender。所以現在你知道按鈕被點擊了。

所以現在唯一的問題是如何從不同的方法中引用sender。

這就是爲什麼有實例變量。你必須準備一個UIButton實例變量或屬性。我們稱之爲theButton。然後在Buttonclicked:你會集theButton（到sender）。在任何其他方法中，您可以得到theButton並做任何你喜歡的事情。

Answer 2

只需按住按鈕的標籤即可。例如，;

@implementation ViewController 
@synthesize tegelEen,tegelTwee; //tegelEen is a button an so is tegelTwee 
int lastClickedButtonTag; 

- (void)viewDidLoad 
{ 
    tegelEen.tag = 1; 
    tegelTwee.tag = 2; 
} 

-(IBAction)Buttonclicked:(UIButton *)sender 
{ 
    lastClickedButtonTag = sender.tag; 

    picController = [[UIImagePickerController alloc]init]; 
    picController.delegate = self; 
    picController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 

    [self presentViewController:picController animated:YES completion:nil]; 
} 

-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{ 
    UIImage *btnImage = [info objectForKey:UIImagePickerControllerOriginalImage]; 

    //Now it changes the button that was clicked. 

    if (lastClickedButtonTag == 1) [tegelEen setImage:btnImage forState:UIControlStateNormal]; 
    else if (lastClickedButtonTag == 2) [tegelTwee setImage:btnImage forState:UIControlStateNormal]; 

    [self dismissViewControllerAnimated:YES completion:nil]; 
}