DataGrid中的复杂对象标题绑定问题

Question

听起来很像其他关于绑定标题的问题 - 但通常它们是关于简单的标题，如 TextBoxes....

我的标题需要使用一个对象实例化，其中包含多个图像和文本组件，称为 EMSPlanViewDeviceNew。这有一个名为 TheDeviceProperty 的 DP，它保存设备的所有数据。

这就是我设置列标题的方式

DataGridTemplateColumn  TextColumn2 = new DataGridTemplateColumn();
FrameworkElementFactory TextBorder2 = new FrameworkElementFactory(typeof(EMSTextCell));
FrameworkElementFactory TextBlock2  = new FrameworkElementFactory(typeof(TextBlock));

ImageTemplate              = new DataTemplate();
TextColumn2.CellTemplate   = ImageTemplate;

// Setup a Header Template to use for the backup paths column
System.Windows.DataTemplate BackupHeaderTemplate  = new System.Windows.DataTemplate();
Binding HeaderBinding        = new Binding("BackupPaths[" + index.ToString() + "].BackupDevice");

FrameworkElementFactory MVDeviceColumnHeader = new FrameworkElementFactory(typeof(EMSPlanViewDeviceNew));
MVDeviceColumnHeader.SetValue(EMSPlanViewDeviceNew.HeightProperty, (double)60);
MVDeviceColumnHeader.SetValue(EMSPlanViewDeviceNew.WidthProperty, (double)85);
MVDeviceColumnHeader.SetValue(EMSPlanViewDeviceNew.TheDeviceProperty, HeaderBinding);

BackupHeaderTemplate.VisualTree = MVDeviceColumnHeader;

TextColumn2.HeaderTemplate = BackupHeaderTemplate;

Dataset 包含具有 BackupDevice、BackupStatus 和 BackupLevel 属性的 BackupPaths 列表。在运行时，填充了网格并绘制了标题对象，但是标题对象没有显示正确的数据，只是默认值，所以这告诉我绑定没有正确连接到数据集，或者它只是在这样就不会调用对象中的“UpdateVisuals”方法，因此不会用正确的数据重绘标题。 我在这里看到的解决方案建议使用 HeaderTemplate，但我认为我正在这样做，所以我不确定还有什么可以尝试让它触发绑定。

这是它在运行时的样子

标题行对象应与第一列图像相同。

谁能建议我还需要做什么来纠正我的错误。谢谢。

public class BackupDataSet

{ 私人字符串_TheAddress； 公共字符串 TheAddress { 得到 { 返回 _TheAddress; } 设置 { _TheAddress = 值； } }

private EMSDevices.EMSBasicDevice _TheDevice;
public EMSDevices.EMSBasicDevice TheDevice
{
    get { return _TheDevice; }
    set { _TheDevice = value; }
}

private BitmapImage _DeviceIcon;
public BitmapImage  DeviceIcon
{
    get { return _DeviceIcon; }
    set { _DeviceIcon = value; }
}

private string _TheIdent;
public string  TheIdent
{
    get { return _TheIdent; }
    set { _TheIdent = value; }
}

private string _TheMainSignalPath;
public string  TheMainSignalPath
{
    get { return _TheMainSignalPath; }
    set { _TheMainSignalPath = value; }
}

public string BackupPathsCount
{
    get
    {
        if (CountGoodBackupPaths() > 0)
            return CountGoodBackupPaths().ToString();
        else if (CountLowBackupPaths() > 0)
            return (-1 * CountLowBackupPaths()).ToString();
        else
            return "--";
    }
}

private List<EMSDevices.EMSBackupPath> _BackupPaths;
public List<EMSDevices.EMSBackupPath>  BackupPaths
{
    get { return _BackupPaths; }
    set { _BackupPaths = value; }
}

public void AddBackupPath(EMSDevices.EMSBasicDevice backupDevice, EMSDevices.SignalSetting backupStatus, int backupLevel)
{
    EMSDevices.EMSBackupPath NewBackupPath = new EMSDevices.EMSBackupPath(backupDevice, backupStatus, backupLevel);

    _BackupPaths.Add(NewBackupPath);
}

public BackupDataSet(string address, BitmapImage icon, string ident, string mainsignalpath)
{
    _TheAddress        = address;
    _DeviceIcon        = icon;
    _TheIdent          = ident;
    _TheMainSignalPath = mainsignalpath;

    _BackupPaths       = new List<EMSDevices.EMSBackupPath>();
}

public BackupDataSet(EMSDevices.EMSBasicDevice device)
{
    _TheAddress        = device.TheAddress;
    _TheDevice         = device.Clone();
    _TheMainSignalPath = device.TheMainSignalPath;

    _BackupPaths       = new List<EMSDevices.EMSBackupPath>();
}

public int CountGoodBackupPaths()
{
    List<EMSDevices.EMSBackupPath> Paths = new List<EMSDevices.EMSBackupPath>();

    Paths = (from BackupPath in _BackupPaths
                where BackupPath.BackupStatus == EMSDevices.SignalSetting.GoodSignal
                select BackupPath).ToList();

    return Paths.Count;
}

public int CountLowBackupPaths()
{
    List<EMSDevices.EMSBackupPath> Paths = new List<EMSDevices.EMSBackupPath>();

    Paths = (from BackupPath in _BackupPaths
                where BackupPath.BackupStatus == EMSDevices.SignalSetting.LowSignal
                select BackupPath).ToList();

    return Paths.Count;
}

}

这是数据集的填充方式：

if (AllCIEDevices.Count > 0)

{ CIEDataSet = new List();

foreach(EMSDevices.EMSBasicDevice dev1 in AllCIEDevices)
{
    BackupDataSet dataset = new BackupDataSet(dev1);

    foreach(EMSDevices.EMSBackupPath backup in dev1.BackupPaths)
    {
        dataset.AddBackupPath(backup.BackupDevice, backup.BackupStatus, backup.BackupLevel);
    }
    CIEDataSet.Add(dataset);
}
// Setup the grid for devices that have the CIE as the parent
PanelDeviceView.ItemsSource   = CIEDataSet; 
SetupDataGrid(PanelDeviceView, Headers);

}

所以 DataGrid 已经通过 PanelDeviceView.ItemSource 连接了数据集。

每一行数据都有一个设备、一些其他参数和一个备份路径列表。

Answer 1

将Binding的Source属性设置为定义BackupPaths属性的对象：

Binding HeaderBinding = new Binding("BackupPaths[" + index.ToString() + "].BackupDevice") { Source = this };