Question

我在.xib文件中设计了一个UIViewController。它使用Autolayout。

我有一个UISlider，它在值改变时更改了UILabel的文本：我已将发送的事件“Value changed”链接到我的头文件，然后在我的控制器的.m文件中实现该功能。此方法仅更改标签的文本，具体取决于滑块的值。

当视图出现时，滑块不显示（设置在屏幕外）。我使用动画在视图上呈现它。问题是当我更改滑块的值时，它会自动调用

 -(void)viewDidLayoutSubviews
{
}

不幸的是，它将控制器视图的所有子视图重置为原始位置。

如何呈现滑块以“破坏”实际布局。

修改

界面构建器中我的滑块连接： enter image description here

和相关函数的代码：

- (IBAction)sliderDureeValueChanged:(id)sender {
    dureeMois = (int) sliderDuree.value;
    if (sliderDuree.maximumValue == sliderDuree.value)
    {
        [lblDuree setText:@"Max"];
    }
    else if (sliderDuree.minimumValue == sliderDuree.value)
    {
        [lblDuree setText:@"Min"];
    }
    else
    {
        [lblDuree setText:[NSString stringWithFormat:@"%d month",dureeMois]
    }
}

EDIT2

以下是使用滑块调用[NSThread callStackSymbols]时viewDidLayoutSubviews获得的堆栈。

2013-07-16 16:39:47.420 MyApp[2363:907] Stack trace : (
    0   MyApp                               0x0003cd5f -[GraphiqueFVViewController viewDidLayoutSubviews] + 50
    1   UIKit                               0x34f938c9 <redacted> + 456
    2   QuartzCore                          0x34d3dd8b <redacted> + 214
    3   QuartzCore                          0x34d3d929 <redacted> + 460
    4   QuartzCore                          0x34d3e85d <redacted> + 16
    5   QuartzCore                          0x34d3e243 <redacted> + 238
    6   QuartzCore                          0x34d3e051 <redacted> + 316
    7   QuartzCore                          0x34d3deb1 <redacted> + 60
    8   CoreFoundation                      0x3315d6cd <redacted> + 20
    9   CoreFoundation                      0x3315b9c1 <redacted> + 276
    10  CoreFoundation                      0x3315bd17 <redacted> + 742
    11  CoreFoundation                      0x330ceebd CFRunLoopRunSpecific + 356
    12  CoreFoundation                      0x330ced49 CFRunLoopRunInMode + 104

    13  GraphicsServices                    0x36c922eb GSEventRunModal + 74
    14  UIKit                               0x34fe4301 UIApplicationMain + 1120
    15  MyApp                               0x00021add main + 116
    16  libdyld.dylib                       0x3b264b20 <redacted> + 0

并在调试区域中回溯所有内容：

* thread #1: tid = 0x2503, 0x00101d46 MyApp`-[GraphiqueFVViewController viewDidLayoutSubviews](self=0x1ed972f0, _cmd=0x3541247c) + 42 at GraphiqueFVViewController.m:386, stop reason = breakpoint 2.1
    frame #0: 0x00101d46 MyApp`-[GraphiqueFVViewController viewDidLayoutSubviews](self=0x1ed972f0, _cmd=0x3541247c) + 42 at GraphiqueFVViewController.m:386
    frame #1: 0x34f938c8 UIKit`-[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 456
    frame #2: 0x34d3dd8a QuartzCore`-[CALayer layoutSublayers] + 214
    frame #3: 0x34d3d928 QuartzCore`CA::Layer::layout_if_needed(CA::Transaction*) + 460
    frame #4: 0x34d3e85c QuartzCore`CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 16
    frame #5: 0x34d3e242 QuartzCore`CA::Context::commit_transaction(CA::Transaction*) + 238
    frame #6: 0x34d3e050 QuartzCore`CA::Transaction::commit() + 316
    frame #7: 0x34d3deb0 QuartzCore`CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 60
    frame #8: 0x3315d6cc CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 20
    frame #9: 0x3315b9c0 CoreFoundation`__CFRunLoopDoObservers + 276
    frame #10: 0x3315bd16 CoreFoundation`__CFRunLoopRun + 742
    frame #11: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
    frame #12: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
    frame #13: 0x36c922ea GraphicsServices`GSEventRunModal + 74
    frame #14: 0x34fe4300 UIKit`UIApplicationMain + 1120
    frame #15: 0x000e6a84 MyApp`main(argc=1, argv=0x2fd1bd18) + 116 at main.m:16
    frame #16: 0x3b264b20 libdyld.dylib`start + 4

  thread #3: tid = 0x2903, 0x3b31b648 libsystem_kernel.dylib`kevent64 + 24
    frame #0: 0x3b31b648 libsystem_kernel.dylib`kevent64 + 24
    frame #1: 0x3b2544f0 libdispatch.dylib`_dispatch_mgr_invoke + 796
    frame #2: 0x3b246df8 libdispatch.dylib`_dispatch_mgr_thread$VARIANT$up + 36

  thread #5: tid = 0x2b03, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
    frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
    frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
    frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
    frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
    frame #6: 0x390cd504 WebCore`RunWebThread(void*) + 444
    frame #7: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #7: tid = 0x241f, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
    frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
    frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
    frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
    frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
    frame #6: 0x33a1b3d4 Foundation`+[NSURLConnection(Loader) _resourceLoadLoop:] + 308
    frame #7: 0x33a9ee84 Foundation`__NSThread__main__ + 972
    frame #8: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #8: tid = 0x2d03, 0x3b32b594 libsystem_kernel.dylib`select$DARWIN_EXTSN + 20
    frame #0: 0x3b32b594 libsystem_kernel.dylib`select$DARWIN_EXTSN + 20
    frame #1: 0x331611f6 CoreFoundation`__CFSocketManager + 678
    frame #2: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #11: tid = 0x3003, 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
    frame #0: 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
    frame #1: 0x3b27cd2e libsystem_c.dylib`_pthread_cond_wait + 646
    frame #2: 0x3b27caa4 libsystem_c.dylib`pthread_cond_timedwait + 44
    frame #3: 0x37088c74 JavaScriptCore`WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 108
    frame #4: 0x3719a556 JavaScriptCore`JSC::BlockAllocator::blockFreeingThreadMain() + 82
    frame #5: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
    frame #6: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #12: tid = 0x3103, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
    frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
    frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
    frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
    frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
    frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
    frame #6: 0x39167d06 WebCore`WebCore::runLoaderThread(void*) + 142
    frame #7: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
    frame #8: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #15: tid = 0x3403, 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
    frame #0: 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
    frame #1: 0x3b27cd2e libsystem_c.dylib`_pthread_cond_wait + 646
    frame #2: 0x3b286f18 libsystem_c.dylib`pthread_cond_wait + 40
    frame #3: 0x37088c46 JavaScriptCore`WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 62
    frame #4: 0x392e1e8c WebCore`WTF::PassOwnPtr<WebCore::StorageTask> WTF::MessageQueue<WebCore::StorageTask>::waitForMessageFilteredWithTimeout<bool (WebCore::StorageTask*)>(WTF::MessageQueueWaitResult&, bool (&)(WebCore::StorageTask*), double) + 56
    frame #5: 0x392e1e40 WebCore`WebCore::StorageThread::threadEntryPoint() + 124
    frame #6: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
    frame #7: 0x3b284310 libsystem_c.dylib`_pthread_start + 308

  thread #17: tid = 0x3903, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
    frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366

  thread #18: tid = 0x3b03, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
    frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366

  thread #19: tid = 0x3707, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
    frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
    frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366

Answer 1

嘿嘿来到这里的派对已经很晚了，但我们遇到了相同的问题，我想对此有所了解。

我们的主视图中包含3个视图：标签，包含登录字段的视图以及包含facebook按钮的视图。当您按下按钮时，它将在2个登录视图之间切换，当它遇到错误时，标签将缩放为0，切换文本，然后缩小到1.我们发现当标签动画并更改大小时，将重新应用约束，并将第一个视图切换回位置。

我们发现“didLayoutSubviews”的文档说当视图更改边界时，它会在视图的父级上调用。我们假设在修改视图的变换时它也会被视为更改边界。

所以问题是如果一个视图动画化，它将导致它的所有兄弟视图重新定位到它们的原始状态。

我们通过将标签放在自己的视图中来解决这个问题。当它动画时，它会在其父级上调用“layoutSubviews”，它只会自行布局。

阻止视图布局子视图

1 个答案: