如何正确搭配?不显示UIAlertView，仅显示灰屏 [英] How to multithred correctly? UIAlertView is not displayed, only gray screen

问题描述

我在我的项目中实现了textToSpeech，并希望在说文本时显示警报视图.在这里，我正在调用textToSpeech的方法:

i have implemented textToSpeech in my project and want to display an alertview while text is spoken. here i am calling the methods for textToSpeech:

//-----before TTS starts i try to display alertView with Cancelbutton  
//[self performSelectorOnMainThread:@selector(alertWhileTTS) withObject:nil waitUntilDone:YES]; //gray view and no alertview
//[self performSelector:@selector(alertWhileTTS)];  //gray view and no alertview
//[self alertWhileTTS];  //gray view and no alertview

//this part here is blocking, no gray screen, 
//after TTS is ready, the alertView is displayed
dispatch_async(dispatch_get_main_queue(), ^{
        //Update UI if you have to
        [self alertWhileTTS];
    });


[[self view] setNeedsDisplay];
[self synthesizeInBackground];
[queue waitUntilAllOperationsAreFinished];
[self setIsSpeaking: false];
[[self view] setNeedsDisplay];  

这是synthesizeInBackground方法(在方法中为 synthesize 启动TTS ):

Here the synthesizeInBackground method(in method synthesize starts the TTS):

- (void) synthesizeInBackground {
    queue = [[NSOperationQueue alloc] init];
    operation = [[NSInvocationOperation alloc] initWithTarget:self 
    selector:@selector(synthesize) object:nil];

    [queue addOperation: operation];
}  

在TTS中，我想显示带有cancel按钮的alertView.但是在我的情况下，我只有一个没有alertView的灰色屏幕.

While TTS i want to display an alertView with cancel button. But in my case i am only getting a gray screen without the alertView.

如何正确调用alertWhileTTS ，以便显示alertView?

How can i call alertWhileTTS correctly, so the alertView gets displayed?

这是alertWhileTTS的内容:

here is the content of alertWhileTTS:

- (void) alertWhileTTS {
UIAlertView *inboxRead = [[[UIAlertView alloc] initWithTitle:@"Inbox tts..."
                                                    message:nil
                                                   delegate:self
                                          cancelButtonTitle:@"Abbrechen"
                                          otherButtonTitles:nil] autorelease];
inboxRead.tag = 997;

[inboxRead show];
}  

更新，查看有效的解决方案:

UPDATE see my solution, that works:

[self performSelectorOnMainThread:@selector(alertWhileTTS) withObject:nil waitUntilDone:YES];

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, (unsigned long)NULL), ^(void) {
        [[self view] setNeedsDisplay];
        [self synthesizeInBackground];
        [queue waitUntilAllOperationsAreFinished];
        [self setIsSpeaking: false];
        [[self view] setNeedsDisplay];

    }); 

推荐答案

更改alertWithTTsTo

Change the alertWithTTsTo

UIAlertView *inboxRead = [[[UIAlertView alloc] initWithTitle:@"Inbox tts..."
                                                    message:nil
                                                   delegate:self
                                          cancelButtonTitle:@"Abbrechen"
                                          otherButtonTitles:nil] autoRelease];
inboxRead.tag = 997;

[inboxRead show];

也不要忘记从主ui线程调用函数alertWhileTTS 通过做

Also dont forget to call the function alertWhileTTS from the main ui thread By doing

 dispatch_async(dispatch_get_main_queue(), ^{
        //Update UI if you have to
        [self alertWhileTTS];
    });

这篇关于如何正确搭配?不显示UIAlertView，仅显示灰屏的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！