Question

即时通讯使用followng方法，在使用时间戳检测时显示图像 dispatch_async（dispatch_get_main_queue（），做UIImageView，它永远不会工作它应该打开一个新的屏幕全尺寸图像吧，

        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];
       ;
       });

我的完整代码

 - (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

您永远不会将myImageView作为子视图添加到任何视图。

Answer 2

尝试在代码中使用此代码。

[self.view addSubview:myImageView];

Answer 3

您正在创建ImageView，为其分配图像并释放ImageView。换句话说，您不会在任何地方显示ImageView。

如果您无法执行[self.view addSubview:imageView]之类的操作，则表示您未在UIViewController子类上运行此代码。

您基本上需要在发布之前添加此创建的ImageView作为当前视图的子视图。

您在哪个类中运行此代码？您知道当前正在显示哪个View Controller吗？

UIImageView图像根本没有显示出来

3 个答案: