wpf - 如何从DataGridColumn获取DataGridColumnHeader？

Question

我的代码如下:

 void mainDataContextObj_CutSelectedColumnEvent(string columnId)
    {
        IList<DataGridColumn> columns = dg.Columns;

        for(int i=2; i<dg.Columns.Count; i++)
        {
            DataGridColumnHeader headerObj = dg.Columns[i].Header as DataGridColumnHeader;

             //This always returns headerObj as null!!!

        }
    }

我需要列中的DataGridColumnHeader。我哪里出错了？

Answer 1

DataGridColumn 的 Header 对象实际上是该列的可见标题，无论您将其设置为什么。 DataGridColumn 不是可视化树的一部分，因此没有直接的方法来访问它的 DataGridColumnHeader(我们甚至无法确定它是否存在)。但您可以执行类似的操作来尝试访问它

DataGridColumnHeader headerObj = GetColumnHeaderFromColumn(column);

private DataGridColumnHeader GetColumnHeaderFromColumn(DataGridColumn column)
{
    // dataGrid is the name of your DataGrid. In this case Name="dataGrid"
    List<DataGridColumnHeader> columnHeaders = GetVisualChildCollection<DataGridColumnHeader>(dataGrid);
    foreach (DataGridColumnHeader columnHeader in columnHeaders)
    {
        if (columnHeader.Column == column)
        {
            return columnHeader;
        }
    }
    return null;
}

public List<T> GetVisualChildCollection<T>(object parent) where T : Visual
{
    List<T> visualCollection = new List<T>();
    GetVisualChildCollection(parent as DependencyObject, visualCollection);
    return visualCollection;
}

private void GetVisualChildCollection<T>(DependencyObject parent, List<T> visualCollection) where T : Visual
{
    int count = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < count; i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(parent, i);
        if (child is T)
        {
            visualCollection.Add(child as T);
        }
        else if (child != null)
        {
            GetVisualChildCollection(child, visualCollection);
        }
    }
}