Xamarin.iOS内存泄漏排查：如何编程监控iOS内存消耗及警告阈值？

以下是Xamarin.iOS中可直接使用的内存获取方法，返回值是iOS系统统计应用物理内存占用的核心指标phys_footprint，和触发ReceiveMemoryWarning的统计口径完全一致：

using System;
using Foundation;
using ObjCRuntime;
using System.Runtime.InteropServices;

public static long GetCurrentIosMemoryConsumption()
{
    const int TASK_VM_INFO = 22;
    // iOS13+用78，iOS12及以下改为37即可
    const int TASK_VM_INFO_COUNT = 78; 

    var taskInfo = new task_vm_info_data_t();
    uint count = (uint)Marshal.SizeOf(taskInfo) / sizeof(uint);

    int status = task_info(mach_task_self(), TASK_VM_INFO, ref taskInfo, ref count);
    if (status != 0)
    {
        // 调用失败可以返回-1做异常处理
        return -1;
    }
    // 返回值单位为字节，转MB的话除以1024*1024即可
    return (long)taskInfo.phys_footprint;
}

// 原生API绑定和结构体定义
[StructLayout(LayoutKind.Sequential)]
struct task_vm_info_data_t
{
    public nuint virtual_size;
    public nuint resident_size;
    public nuint resident_size_max;
    public nuint free_count;
    public nuint active_count;
    public nuint inactive_count;
    public nuint wire_count;
    public nuint zero_fill_count;
    public nuint reactivations;
    public nuint pageins;
    public nuint pageouts;
    public nuint faults;
    public nuint cow_faults;
    public nuint lookups;
    public nuint hits;
    public nuint purgeable_count;
    public nuint purges;
    public nuint speculative_count;
    public nuint decompressions;
    public nuint compressions;
    public nuint swapins;
    public nuint swapouts;
    public nuint compressor_page_count;
    public nuint throttled_count;
    public nuint external_page_count;
    public nuint internal_page_count;
    public nuint phys_footprint;
}

[DllImport(ObjCRuntime.Constants.libSystemLibrary)]
extern static int task_info(uint target_task, int flavor, ref task_vm_info_data_t task_info_out, ref uint task_info_out_count);

[DllImport(ObjCRuntime.Constants.libSystemLibrary)]
extern static uint mach_task_self();

你可以直接在定位/渲染的循环里调用：

Console.WriteLine($"Current mem: {GetCurrentIosMemoryConsumption() / 1024 / 1024} MB");

• 每次打印内存前先手动调用GC.Collect(2); GC.WaitForPendingFinalizers(); 回收所有可释放的托管对象，剩下的内存增长就是非托管资源泄漏导致的
• 高频渲染场景重点检查CGImage、CGBitmapContext、UIImage、CGPath这类CoreGraphics对象，每次使用后必须主动调用Dispose()，Xamarin不会自动回收高频创建的非托管对象
• 检查CLLocationManager的回调事件、自定义渲染视图的事件订阅，避免循环引用导致页面/组件无法释放

你提到Instruments里累计分配释放的7GiB是临时内存，属于正常现象，只要phys_footprint数值持续上涨，就说明确实存在未释放的持久化内存，和触发内存崩溃的统计逻辑完全匹配。

内容的提问来源于stack exchange，提问作者Tom