我有一组标签,它们放置在UIViews
单个UIScrollView
. 他们没有被分配一个出口。我对它们都使用了 Avenir Next Ultralight 字体,它们有不同的大小。
主视图有一个嵌套在导航控制器中的视图控制器。
我刚刚检查了分配情况,并注意到加载时使用这个单一视图会消耗大约 10MB 的内存,其中 8MB 是这些标签,当我转到下一个视图时,该分配仍然有效。
这可能是什么原因造成的?
这是记录分配的快照。
Snapshot Timestamp Growth # Persistent
VM: UILabel (CALayer) 7.90 MB 10
0x5417000 00:02.950.428 1.23 MB
0x5553000 00:02.967.675 1.23 MB
0x568f000 00:02.978.283 1.23 MB
0x591d000 00:03.013.095 832.00 KB
0x57cb000 00:03.004.334 832.00 KB
0x50a7000 00:02.919.040 832.00 KB
0x5177000 00:02.937.076 832.00 KB
0x5347000 00:02.940.969 832.00 KB
0x52d3000 00:02.998.823 120.00 KB
0x52f1000 00:03.023.068 16.00 KB
这是第一个的堆栈跟踪,其余相同:
0 libsystem_kernel.dylib mach_vm_allocate
1 libsystem_kernel.dylib vm_allocate
2 QuartzCore CA::Render::Shmem::new_shmem(unsigned long)
3 QuartzCore CA::Render::Shmem::new_bitmap(unsigned int, unsigned int, unsigned int, unsigned int)
4 QuartzCore CABackingStoreUpdate_
5 QuartzCore ___ZN2CA5Layer8display_Ev_block_invoke
6 QuartzCore x_blame_allocations
7 QuartzCore CA::Layer::display_()
8 QuartzCore CA::Layer::display_if_needed(CA::Transaction*)
9 QuartzCore CA::Layer::layout_and_display_if_needed(CA::Transaction*)
10 QuartzCore CA::Context::commit_transaction(CA::Transaction*)
11 QuartzCore CA::Transaction::commit()
12 UIKit -[UIApplication _reportAppLaunchFinished]
13 UIKit -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:]
14 UIKit -[UIApplication handleEvent:withNewEvent:]
15 UIKit -[UIApplication sendEvent:]
16 UIKit _UIApplicationHandleEvent
17 GraphicsServices _PurpleEventCallback
18 GraphicsServices PurpleEventCallback
19 CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__
20 CoreFoundation __CFRunLoopDoSource1
21 CoreFoundation __CFRunLoopRun
22 CoreFoundation CFRunLoopRunSpecific
23 CoreFoundation CFRunLoopRunInMode
24 UIKit -[UIApplication _run]
25 UIKit UIApplicationMain
26 main
27 libdyld.dylib start
解决方案
我想我会分享我是如何设法减少这种情况的。事实证明,如果您有自动换行的标签,并且在两侧、顶部和底部周围有大量空白空间,这会增加显示它们所需的内存。因此,解决方案是将空间减少到绝对最小值。
这是生成的快照:
Snapshot Timestamp Growth # Persistent
VM: UILabel (CALayer) 2.37 MB 9
0x5321000 00:02.503.255 208.00 KB
0x5248000 00:02.474.045 392.00 KB
0x5087000 00:02.432.317 208.00 KB
0x50bb000 00:02.445.927 64.00 KB
0x5303000 00:02.498.137 120.00 KB
0x52aa000 00:02.481.354 292.00 KB
0x50cb000 00:02.449.625 180.00 KB
0x5355000 00:02.505.638 112.00 KB
0x50f9000 00:02.455.350 848.00 KB