C# 将图像绘制到 ListView 中的子项

Drawing an Image to a subItem in the ListView

提问by

My Listview is setup in the details view with the following column headers:

我的 Listview 是在详细信息视图中设置的，带有以下列标题：

Image Name || Image Location || Image Size || Image Preview

图片名称 || 图片位置 || 图片尺寸 || 图像预览

I would like to know if there is a way to draw an image in the 4th column there. The only way I know, is to set

我想知道是否有办法在第 4 列中绘制图像。我知道的唯一方法是设置

this.listview1.OwnerDraw = true
this.listView1.DrawColumnHeader += new System.Windows.Forms.DrawListViewColumnHeaderEventHandler(listView1_DrawColumnHeader);
this.listView1.DrawItem += new System.Windows.Forms.DrawListViewItemEventHandler(listView1_DrawItem);
this.listView1.DrawSubItem += new System.Windows.Forms.DrawListViewSubItemEventHandler(listView1_DrawSubItem);

The problem with this is I have to handle ALL the listview drawing myself... I was wondering if there is a better way to draw in image to a subItem, or if there is a way to only handle the DrawSubItem event?

问题是我必须自己处理所有的列表视图绘图......我想知道是否有更好的方法将图像绘制到子项，或者是否有办法只处理 DrawSubItem 事件？

采纳答案by zidane

In listView1_DrawColumnHeaderand listView1_DrawItemevent handlers you should put this

在listView1_DrawColumnHeader和listView1_DrawItem事件处理程序中，你应该把这个

e.DrawDefault = true;

It will use default drawing implementation for columns and items, all you have to do is write your own implementation only for subitems.

它将为列和项目使用默认绘图实现，您所要做的就是仅为子项目编写自己的实现。

回答by Grammarian

ObjectListView(an open source wrapper around a .NET WinForms ListView) trivially supports drawing images in columns without having to do all the owner drawing yourself. The Data tab of the demo shows animated GIFs, which is a bit OTT but it will work equally well with static images.

ObjectListView（一个围绕 .NET WinForms ListView 的开源包装器）简单地支持在列中绘制图像，而不必自己绘制所有所有者。演示的“数据”选项卡显示动画 GIF，这有点 OTT，但它对静态图像同样有效。

With a few lines of code, this is what your ListView can look like:
_{(source: sourceforge.net)}

用几行代码，这就是你的 ListView 的样子：（ _{来源：sourceforge.net）}

回答by Jon Seigel

I just ran into this.

我刚遇到这个。

@zidane's answeris nearly correct. I want to post what actually needs to be done so people reading back later don't have to figure this out themselves.

@zidane 的回答几乎是正确的。我想发布实际需要做的事情，以便以后阅读的人不必自己弄清楚。

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Only handle DrawColumnHeaderusing e.DrawDefault = true;and the subitem drawing. In fact, if you set e.DrawDefault = true;in the DrawItemevent, the DrawSubItemevent never fires, presumably on the assumption that you want to draw the whole row and don't care about the subitems.

只处理DrawColumnHeader使用e.DrawDefault = true;和子项绘图。事实上，如果您e.DrawDefault = true;在DrawItem事件中设置，则DrawSubItem事件永远不会触发，大概是基于您想要绘制整行而不关心子项的假设。

The only real code is in DrawSubItem, using this basic construction:

唯一真正的代码在 中DrawSubItem，使用以下基本结构：

if (/* condition to determine if you want to draw this subitem */)
{
    // Draw it
}
else
    e.DrawDefault = true;

回答by CrazyTim

Building upon previous answers, here's a full VB.NET example:

基于以前的答案，这是一个完整的 VB.NET 示例：

Public Class MyListView : Inherits System.Windows.Forms.ListView

Public Sub New()
    MyBase.New()
    MyBase.OwnerDraw = True
End Sub

Protected Overrides Sub OnDrawSubItem(ByVal e As DrawListViewSubItemEventArgs)
    If x Then ' condition to determine if you want to draw this subitem
        ' draw code goes here
    Else
        e.DrawDefault = True
    End If
    MyBase.OnDrawSubItem(e)
End Sub

Protected Overrides Sub OnDrawColumnHeader(ByVal e As DrawListViewColumnHeaderEventArgs)
    e.DrawDefault = True
    MyBase.OnDrawColumnHeader(e)
End Sub

Protected Overrides Sub OnDrawItem(e As System.Windows.Forms.DrawListViewItemEventArgs)
    e.DrawDefault = True
    MyBase.OnDrawItem(e)
End Sub

End Class