UIImageView圖像根本不顯示

Question

我正在使用followng方法，以便在檢測到時間戳時顯示圖像，正在使用dispatch_async（dispatch_get_main_queue（）來執行UIImageView，它從不工作，應該打開一個新的全尺寸圖像，

        dispatch_async(dispatch_get_main_queue(), ^{



            UIImage *myImage = [UIImage imageNamed:@"img.jpg"];

            UIImageView *myImageView = [[UIImageView alloc] initWithImage:myImage];

            [myImageView setFrame:CGRectMake(0, 0, 100, 200)];

            [myImageView release];
       ;
       });

我的完整代碼

 - (void) onPayload:(PayloadEvent *) event

{

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

NSString *header = @"[OnPayload] ";

if (event.payloadType == TYPE_IDENTIFIED)

{


    if ((event.contentID != -1) && (event.timeStamp == -1))

    {

        [mUI performSelectorOnMainThread: @selector(Trace:) withObject:[NSString stringWithFormat:@"%@ StaticID detected: %x\t\tConfidence: %f\n", header,(int)event.contentID, event.confidence]  waitUntilDone:NO];

    }

    if ((event.timeStamp != -1) && (event.contentID == -1))



    {

        [mUI performSelectorOnMainThread: @selector(Trace:) withObject:[NSString stringWithFormat:@"%@ Timestamp detected: %f\t\tConfidence: %f\n", header, event.timeStamp, event.confidence]  waitUntilDone:NO];
 dispatch_async(dispatch_get_main_queue(),  ^{

            UIImage *myImage = [UIImage imageNamed:@"img.jpg"];

            UIImageView *myImageView = [[UIImageView alloc] initWithImage:myImage];

            [myImageView setFrame:CGRectMake(0, 0, 100, 200)];

            [myImageView release];



;  });

Answer 1

您永遠不會將myImageView作為子視圖添加到任何視圖。

Answer 2

嘗試在您的代碼中使用此代碼。

[self.view addSubview:myImageView];

Answer 3

您正在創建一個ImageView，為其分配一個Image並釋放該ImageView。 換句話說，您不會在任何地方顯示ImageView。

如果您無法執行[self.view addSubview:imageView] ，則意味着您沒有在UIViewController子類上運行此代碼。

基本上，您需要在釋放它之前將要創建的此ImageView添加為當前視圖的子視圖。

您在哪個類中運行此代碼？ 您知道當前正在顯示哪個View Controller嗎？