使用进度条创建自定义单元格元素时，RadListView 有奇怪的行为 [英] RadListView has strange behavior when creating custom cell element with progressbar

问题描述

当我需要在列表视图的单元格内创建进度条时，我遇到了 WinForms 的 RadListView 的一个非常奇怪的行为.它最初创建带有进度条的单元格，但是当我左右滚动列表视图时，进度条元素移动到左侧一列.

I'm experiencing a very strange behavior of the RadListView for WinForms when I need to create a progress bar inside a listview's cell. It initially creates cells with progress bars but when I scroll the listview left and right, the progress bar elements move to the left one column.

这是我用进度条插入创建单元格的代码:

Here is my code to insert create cell with progress bar:

_processingList = new RadListView();
_processingList.CellCreating += new ListViewCellElementCreatingEventHandler(_list_CellCreating);
_processingList.ViewType = ListViewType.DetailsView;
_processingList.Dock = System.Windows.Forms.DockStyle.Fill;
_processingList.HeaderHeight = 16;
_processingList.Columns.Add("Source");
_processingList.Columns.Add("Dir");
_processingList.Columns.Add("Destination");
_processingListProgressColumn = new ListViewDetailColumn("Progress", "");
_processingList.Columns.Add(_processingListProgressColumn);
_processingList.Columns.Add("Size");
_processingList.Columns.Add("Priority");
_processingList.Columns.Add("Status");
_processingList.Columns.Add("Start Time");
_processingList.Columns.Add("Elapsed");
_processingList.Columns.Add("Left");

...

void _list_CellCreating(object sender, ListViewCellElementCreatingEventArgs e)
{
    DetailListViewDataCellElement dataCell = e.CellElement as DetailListViewDataCellElement;

    if (dataCell != null && dataCell.Data == _processingListProgressColumn)
    {
        e.CellElement = new ProgressBarCellElement(dataCell.RowElement, dataCell.Data);
    }
}

class ProgressBarCellElement : DetailListViewDataCellElement
{
    private RadProgressBarElement progressBar;

    public ProgressBarCellElement(DetailListViewVisualItem owner, ListViewDetailColumn column)
        : base(owner, column)
    {

    }

    protected override void CreateChildElements()
    {
        base.CreateChildElements();

        this.progressBar = new RadProgressBarElement();
        this.progressBar.StretchHorizontally = this.progressBar.StretchVertically = true;

        this.Children.Add(this.progressBar);
    }

    public override void Synchronize()
    {

        base.Synchronize();
        this.Text = "";

        try
        {
            this.progressBar.Value1 = Convert.ToInt32(this.Row[this.column]);
        }
        catch { }

    }

    protected override Type ThemeEffectiveType
    {
        get
        {
            return base.ThemeEffectiveType;
        }
    }
}

有人可以有很好的解释或向我指出如何在某些单元格内创建带有 ProgressBar 的 RadListView 的正确方法吗?

Can someone have good explanation or point me to how to the right way to create the RadListView with ProgressBar inside some cells?

推荐答案

RadListView 在详细信息视图中对其单元使用虚拟化，因此在滚动等操作期间可以重用单元.要处理这种情况，您应该首先指定您的单元格应该使用哪一列，并且还应该为其余情况设置默认单元格.这是一个完整的例子:

RadListView uses virtualization for its cells in details view, so cells are being reused during operations like scrolling. To handle this case, you should first specify which column your cells should work with and also, you should set a default cell for the rest of the cases. Here is a complete example:

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        InitializeComponent();

        radListView1 = new RadListView();
        radListView1.Parent = this;
        this.Controls.SetChildIndex(radListView1, 0);
        radListView1.CellCreating += new ListViewCellElementCreatingEventHandler(_list_CellCreating);
        radListView1.ViewType = ListViewType.DetailsView;
        radListView1.Dock = System.Windows.Forms.DockStyle.Fill;
        radListView1.HeaderHeight = 16;
        radListView1.Columns.Add("Source");
        radListView1.Columns.Add("Dir");
        radListView1.Columns.Add("Destination");
        _processingListProgressColumn = new ListViewDetailColumn("Progress", "");
        radListView1.Columns.Add(_processingListProgressColumn);
        radListView1.Columns.Add("Size");
        radListView1.Columns.Add("Priority");
        radListView1.Columns.Add("Status");
        radListView1.Columns.Add("Start Time");
        radListView1.Columns.Add("Elapsed");
        radListView1.Columns.Add("Left");

        for (int i = 0; i < 60; i++)
        {
            radListView1.Items.Add("src", "dir", "dest", i * 1.14, "123", "high", "stat", "start", "elapsed", "left");
        }
    }

    ListViewDetailColumn _processingListProgressColumn;

    private void _list_CellCreating(object sender, ListViewCellElementCreatingEventArgs e)
    {
        DetailListViewDataCellElement dataCell = e.CellElement as DetailListViewDataCellElement;

        if (dataCell != null)
        {
            if (dataCell.Data == _processingListProgressColumn)
            {
                e.CellElement = new ProgressBarCellElement(dataCell.RowElement, dataCell.Data);
            }
            else
            {
                e.CellElement = new DefaultCellElement(dataCell.RowElement, dataCell.Data);
            }
        }
    }

    class DefaultCellElement : DetailListViewDataCellElement
    {
        public DefaultCellElement(DetailListViewVisualItem owner, ListViewDetailColumn column) :
            base(owner, column)
        {

        }
        public override bool IsCompatible(ListViewDetailColumn data, object context)
        {
            return data.Name != "Progress";
        }

        protected override Type ThemeEffectiveType
        {
            get
            {
                return base.ThemeEffectiveType;
            }
        }
    }

    class ProgressBarCellElement : DetailListViewDataCellElement
    {
        private RadProgressBarElement progressBar;

        public ProgressBarCellElement(DetailListViewVisualItem owner, ListViewDetailColumn column)
            : base(owner, column)
        {

        }

        public override bool IsCompatible(ListViewDetailColumn data, object context)
        {
            return data.Name == "Progress";
        }

        protected override void CreateChildElements()
        {
            base.CreateChildElements();

            this.progressBar = new RadProgressBarElement();
            this.progressBar.StretchHorizontally = this.progressBar.StretchVertically = true;

            this.Children.Add(this.progressBar);
        }

        public override void Synchronize()
        {

            base.Synchronize();
            this.Text = "";

            try
            {
                this.progressBar.Value1 = Convert.ToInt32(this.Row[this.column]);
            }
            catch { }

        }

        protected override Type ThemeEffectiveType
        {
            get
            {
                return base.ThemeEffectiveType;
            }
        }
    }

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