Winform DataGridView扩展系列(二)

二、多列表头组件的实现:

要求:
同汇总行,不再多说
实现：
组件的实现与控件有些差别,特别是在设计时支持上.

a.组件的层次结构:

[DesignTimeVisible(true)]
[Designer(typeof(ZYQ.Design.Designer.MultiDataGridViewColumnHeadersComponentDesigner), typeof(IDesigner))]
public class MultiDataGridViewColumnHeadersComponent : Component{}
[DefaultProperty("Text")]
public class MultiDataGridViewColumnHeader{}
[Editor(typeof(ZYQ.Design.Utilities.Editor.MultiColumnHeaderEditor), typeof(UITypeEditor))]
public class MultiDataGridViewColumnHeaderCollection : List<MultiDataGridViewColumnHeader>{}

b.设计时支持

public class IncludDataGridViewColumnNameConverter : TypeConverter{}
public class IncludingDataGridViewColumnCollectionConverter:TypeConverter{}
public class IncludingDataGridViewColumnCollectionEditor:CollectionEditor{}
public partial class IncludingDataGridViewColumnEditorFrom : Form{}
public class MultiColumnHeaderEditor : UITypeEditor{}
public partial class MultiColumnHeaderEditorFrom : Form{}
public class MultiDataGridViewColumnHeadersNode : TreeNode{}
public class MultiDataGridViewColumnHeadersComponentDesigner:ComponentDesigner{}

由于嵌套集合vs默认ComponentDesigner不能完整实现设计时代码,所以必须从ComponentDesigner继承一个设计器来实现设计时代码的自动实现。网上有很多帖子是放在Editor中用 ITypeDescriptorContext对象的PropertyDescriptor属性的SetValue方法实现设计时代码的持久序列化，但在组件中不能用。原因就在于设计器无法知道该如何处理ComponentChanged事件提交的更改，所以正确引发ComponentChanged事件并自己处理提交的更改成为自定义设计器的首要任务。

public class MultiDataGridViewColumnHeadersComponentDesigner:ComponentDesigner
{
    ......
    private void InitializeServices()
    {
        ......
        this.svr_componentchange =GetService(typeof(IComponentChangeService));
        if (this.svr_componentchange != null)
        {
        this.svr_componentchange.ComponentChanged += new ComponentChangedEventHandler(changeService_ComponentChanged);
        }
        .......
    }
    void Items_CollectionChanged(object sender, CollectionChangeEventArgs e)
    {
       base.RaiseComponentChanged((MemberDescriptor)TypeDescriptor.GetProperties(_mycomponent)["Items"], null, _mycomponent.Items);
    }
    private void DoTransaction(string propertyname)
    {
        designer_transaction = svr_host.CreateTransaction("Change Items");
        using (designer_transaction)
        {
            PropertyDescriptor itms = TypeDescriptor.GetProperties(_mycomponent)[propertyname];
            itms.SetValue(Component, _mycomponent.Items);
                designer_transaction.Commit();
        }
    }

c.细节与实现：

为配合DataGridView的动作使多列表头跟随改变，必须注册DataGridView的相关事件来重新计算多列表头绘制所需要的数据，他们是：

#region Hook Events
        void items_CollectionChanged(object sender, CollectionChangeEventArgs e)
        {
            //if (Depth!=-1)
                OnDepthChanged();

        }
        void _mygrid_Scroll(object sender, ScrollEventArgs e)
        {
            if (e.ScrollOrientation == ScrollOrientation.HorizontalScroll)
            {
                HeaderPrePanit();
            }
        }
        void _mygrid_ColumnStateChanged(object sender, DataGridViewColumnStateChangedEventArgs e)
        {
            HeaderPrePanit();
        }
        void _mygrid_Paint(object sender, PaintEventArgs e)
        {
            PaintHeader();

        }

        void _mygrid_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
        {
            //绘制表头
            if (e.RowIndex == -1 && this.Depth > 0 && e.ColumnIndex != -1)
            {

                if (!_IsChangedColumnHeadHeigh)
                    _mygrid.ColumnHeadersHeight += (this.Depth) * this.PerHeaderHeight;

            }
        }
        void _mygrid_ColumnHeadersHeightChanged(object sender, EventArgs e)
        {

            if (this.PerHeaderHeight * this.Depth != _mygrid.ColumnHeadersHeight)
            {
                _mygrid.ColumnHeadersHeight = this.Depth* this.PerHeaderHeight;
                _IsChangedColumnHeadHeigh = true;
            }
            else
                _IsChangedColumnHeadHeigh = true;
        }
        void _mygrid_CellMouseLeave(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex == -1)
            {
                //_IsMouseEnter = false;
                _selectColumnindex = -1;
            }
            HeaderPrePanit();
        }

        void _mygrid_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex == -1)
            {
                //_IsMouseEnter = true;
                _selectColumnindex = e.ColumnIndex;
            }
            HeaderPrePanit();
        }

        void _mygrid_ColumnHeaderCellChanged(object sender, DataGridViewColumnEventArgs e)
        {
            HeaderPrePanit();
        }

        void _mygrid_ColumnDividerWidthChanged(object sender, DataGridViewColumnEventArgs e)
        {
            HeaderPrePanit();
        }
        void _mygrid_ColumnWidthChanged(object sender, DataGridViewColumnEventArgs e)
        {
            ReadyHeader();
            HeaderPrePanit();
        }

        void _mygrid_ColumnDisplayIndexChanged(object sender, DataGridViewColumnEventArgs e)
        {
            HeaderPrePanit();
        }

        #endregion

多列表头的绘制应该细分一下。影响宽度的情况有列宽的变化(ColumnWidthChanged)、分隔线宽度变化(可以在绘制边框时处理)、列的Visible属性变化；影响位置的变化有水平Scroll的移动；还有鼠标进入表头时背景色的变化，所以绘制被分为ReadyHeader计算宽度、HeaderPrePaint计算位置、HeaderPostPaint绘制多列表头。

private void PaintHeader()
{
    _mygrid.SuspendLayout();
    if (_IsReady != 4)
    {
        ReadyHeader();
        HeaderPrePanit();
    }
    Graphics g = _mygrid.CreateGraphics();
    PaintEventArgs e = new PaintEventArgs(g, GetHeaderBandRectangle());
    HeaderPostPaint(g, e);
    _mygrid.ResumeLayout(true);
}
private void PaintContext(Graphics g, Rectangle rect, Rectangle cliprect,string text,bool iscolumn){...}
private void PainDividerWidth(Graphics g, int width, Rectangle rect, Rectangle cliprect){...}
private void PaintBackgrond(Graphics g, Rectangle rect, Rectangle clip){...}
private void PaintSelectedBackground(Graphics g, Rectangle rect, Rectangle clip){...}
总结：
使用组件的好处显而易见。但是使用时的闪烁现象没办法克服！N层多列表头呈现完成。

转载请注明:http://www.cnblogs.com/RZYQ/archive/2011/12/28/2305257.html

posted on 2011-12-28 18:05 木木的大象阅读(1338) 评论(1) 收藏举报

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Winform DataGridView扩展系列(二)