如何将 WMI 集合显示到 WPF DataGrid

Question

我刚开始 WPF，有点迷茫。

XAML 代码：

<DataGrid  Name="dgResults" AutoGenerateColumns="True" ItemsSource="{Binding}">
</DataGrid>

C#代码：

private void GetServices(string strComputer)
{
     ManagementScope scope = new ManagementScope(@"\\" + strComputer + @"\root\cimv2");
     SelectQuery query = new SelectQuery("Select * From Win32_Service");
     ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query);
     ManagementObjectCollection services = searcher.Get();
     dgResults.ItemsSource = services;
}

我期待 WMI Win32_Service 查询将 WMI 属性显示为标题，并且返回集合中的每个对象将显示为一行。但它显示了 ManagementObjectCollection 属性。有没有办法转换它并仍然允许访问所有属性？

任何帮助将不胜感激。

Answer 1

这有点棘手。

首先，由于您不想显示 ManagementBaseObject 实例的 CLR 属性，因此您必须使用类型描述符概念来告诉绑定引擎，您有自定义属性。以下是您需要的 CustomTypeDescriptor 和 PropertyDescriptor 的后代：

internal sealed class ManagementObjectPropertDescriptor : PropertyDescriptor
{
    private readonly PropertyData propertyData;

    public ManagementObjectPropertDescriptor(PropertyData propertyData)
        : base(propertyData.Name, null)
    {
        this.propertyData = propertyData;
    }

    public override bool CanResetValue(object component)
    {
        return false;
    }

    public override Type ComponentType
    {
        get { return typeof(ManagementObjectTypeDescriptor); }
    }

    public override object GetValue(object component)
    {
        return propertyData.Value;
    }

    public override bool IsReadOnly
    {
        get { return true; }
    }

    public override Type PropertyType
    {
        get { return propertyData.Value != null ? propertyData.Value.GetType() : typeof(object); }
    }

    public override void ResetValue(object component)
    {
    }

    public override void SetValue(object component, object value)
    {
    }

    public override bool ShouldSerializeValue(object component)
    {
        return false;
    }
}

public sealed class ManagementObjectTypeDescriptor : CustomTypeDescriptor
{
    private PropertyData[] managementObjectProperties;

    public ManagementObjectTypeDescriptor(ManagementBaseObject source)
    {
        this.managementObjectProperties = source
            .Properties
            .Cast<PropertyData>()
            .ToArray();
    }

    public override PropertyDescriptorCollection GetProperties()
    {
        return new PropertyDescriptorCollection(managementObjectProperties
            .Select(p => new ManagementObjectPropertDescriptor(p))
            .ToArray());
    }
}

为简单起见，属性设为只读。
接下来，您需要将ManagementObjectCollection 变成ManagementObjectTypeDescriptor 的集合：

        ManagementScope scope = new ManagementScope(@"\\" + strComputer + @"\root\cimv2");
        SelectQuery query = new SelectQuery("Select * From Win32_Service");

        var typeDescriptors = new ObservableCollection<ManagementObjectTypeDescriptor>();

        using (var searcher = new ManagementObjectSearcher(scope, query))
        {
            using (var managementObjects = searcher.Get())
            {
                foreach (ManagementBaseObject managementObject in managementObjects)
                {
                    using (managementObject)
                    {
                        typeDescriptors.Add(new ManagementObjectTypeDescriptor(managementObject));
                    }
                }
            }
        }

        dgResults.ItemsSource = new ArrayList(typeDescriptors);

请注意，ItemsSource 是 IList 的非泛型实现。 DataGrid 有一个错误，从我的观点来看，这里的行为：如果你将一个通用的IList<ManagementObjectTypeDescriptor> 设置为项目源，DG 将忽略从CustomTypeDescriptor 继承的事实，你会看到网格中根本没有列。同时，非泛型 IList 按预期工作。