以前,我使用这种方法以编程方式设置音量：
MPVolumeView *volumeView = [[MPVolumeView alloc] init];
UiSlider *volumeViewSlider = nil;
for (UIView *view in [volumeView subviews])
{
if ([view.class.description isEqualToString:@"MPVolumeSlider"])
{
volumeViewSlider = (UiSlider *)view;
break;
}
}
[volumeViewSlider setValue:0.5 animated:YES];
[volumeViewSlider sendActionsForControlEvents:UIControlEventTouchUpInside];
直到iOS 11.4它运行良好(即使在iOS 11.3上),但在iOS 11.4上却没有.体积值保持不变.有人可以帮助解决这个问题吗？谢谢.
解决方法
在一小段延迟后更改volumeViewSlider.value可以解决问题.
- (IBAction)increase:(id)sender {
MPVolumeView *volumeView = [[MPVolumeView alloc] init];
UiSlider *volumeViewSlider = nil;
for (UIView *view in volumeView.subviews) {
if ([view isKindOfClass:[UiSlider class]]) {
volumeViewSlider = (UiSlider *)view;
break;
}
}
dispatch_after(dispatch_time(disPATCH_TIME_Now,(int64_t)(0.01 * NSEC_PER_SEC)),dispatch_get_main_queue(),^{
volumeViewSlider.value = 0.5f;
});
}
Swift version