我正在尝试实现一个所有者绘制的ListView，因为基本控件会占用我需要在列中对齐值的制表符。
使用MSDN中的示例作为基础我能够接近。我仍然遇到的唯一问题是，当文本不适合列时使用的省略号周期比默认文本呈现更紧密地间隔在一起;如果字体是粗体，则句点一起运行到下划线。
下面的程序演示了这个问题。它有4个ListView：顶部的两个使用默认渲染绘制。底部的两个是所有者，右侧的一对是粗体。由于长度原因，我删除了我不需要的所有内容以证明问题，这就是为什么ownerdawn ListViews没有列标题。
查看放大的屏幕截图，所有者绘制的ListView中的省略号的周期间隔一个像素;默认图形中的那些具有两个间距像素。当粗体将周期扩展为两个像素时，所有者绘制的合并为一个看起来像下划线的实体块。
文本呈现还存在其他细微差别;省略号是唯一一个在没有缩放的情况下很明显的省略号。然而，这些差异确实让我怀疑问题是一个更普遍的问题。 可能是GDI vs GDI +渲染？除了我认为只能在应用程序级别上有所不同。显然不是，切换Application.SetCompatibleTextRenderingDefault()并没有影响任何内容。
using System;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public class Form1 : Form
{
private void ListViewDrawSubItem(object sender, DrawListViewSubItemEventArgs e)
{
ListView listView = sender as ListView;
using (StringFormat sf = new StringFormat())
{
// Draw the standard background.
e.DrawBackground();
sf.SetTabStops(0, new float[] {12, 12, 12, 12, 12});
sf.FormatFlags = sf.FormatFlags | StringFormatFlags.NoWrap;
sf.Trimming = StringTrimming.EllipsisCharacter;
// Draw the header text.
// passing the controls font directly causes an ArguementException);
using (Font headerFont = new Font(listView.Font.Name, listView.Font.Size, listView.Font.Style))
{
e.Graphics.DrawString(e.SubItem.Text, headerFont, Brushes.Black, e.Bounds, sf);
}
}
}
public Form1()
{
InitializeComponent();
LoadData(listView1);
LoadData(listView2);
LoadData(listView3);
LoadData(listView4);
}
private void LoadData(ListView listView)
{
listView.Columns.Add("first", 35);
listView.Columns.Add("second", 75);
for (int i = 0; i < 5; i++)
{
listView.Items.Add("test");
listView.Items[i].SubItems.Add("test test test test");
}
}
#region from Form1.Designer
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.listView1 = new System.Windows.Forms.ListView();
this.listView2 = new System.Windows.Forms.ListView();
this.listView3 = new System.Windows.Forms.ListView();
this.listView4 = new System.Windows.Forms.ListView();
this.SuspendLayout();
//
// listView1
//
this.listView1.Location = new System.Drawing.Point(12, 12);
this.listView1.Name = "listView1";
this.listView1.Size = new System.Drawing.Size(121, 116);
this.listView1.TabIndex = 0;
this.listView1.UseCompatibleStateImageBehavior = false;
this.listView1.View = System.Windows.Forms.View.Details;
//
// listView2
//
this.listView2.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.listView2.Location = new System.Drawing.Point(151, 12);
this.listView2.Name = "listView2";
this.listView2.Size = new System.Drawing.Size(121, 116);
this.listView2.TabIndex = 1;
this.listView2.UseCompatibleStateImageBehavior = false;
this.listView2.View = System.Windows.Forms.View.Details;
//
// listView3
//
this.listView3.Location = new System.Drawing.Point(12, 134);
this.listView3.Name = "listView3";
this.listView3.OwnerDraw = true;
this.listView3.Size = new System.Drawing.Size(121, 116);
this.listView3.TabIndex = 2;
this.listView3.UseCompatibleStateImageBehavior = false;
this.listView3.View = System.Windows.Forms.View.Details;
this.listView3.DrawSubItem += new System.Windows.Forms.DrawListViewSubItemEventHandler(this.ListViewDrawSubItem);
//
// listView4
//
this.listView4.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.listView4.Location = new System.Drawing.Point(151, 134);
this.listView4.Name = "listView4";
this.listView4.OwnerDraw = true;
this.listView4.Size = new System.Drawing.Size(121, 116);
this.listView4.TabIndex = 3;
this.listView4.UseCompatibleStateImageBehavior = false;
this.listView4.View = System.Windows.Forms.View.Details;
this.listView4.DrawSubItem += new System.Windows.Forms.DrawListViewSubItemEventHandler(this.ListViewDrawSubItem);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(284, 262);
this.Controls.Add(this.listView4);
this.Controls.Add(this.listView3);
this.Controls.Add(this.listView2);
this.Controls.Add(this.listView1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.ListView listView1;
private System.Windows.Forms.ListView listView2;
private System.Windows.Forms.ListView listView3;
private System.Windows.Forms.ListView listView4;
#endregion
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
}
答案 0 :(得分：7)
我找到了draw子项方法的偶然实现。我有的主要警告是标签大小是固定的（虽然如果有必要改变它可以下降到win32）;并且据报道，在我的机器上工作时我需要的标志组合在MSDN中互不兼容。
private void ListViewDrawSubItem(object sender, DrawListViewSubItemEventArgs e)
{
//toggle colors if the item is highlighted
if (e.Item.Selected && e.Item.ListView.Focused)
{
e.SubItem.BackColor = SystemColors.Highlight;
e.SubItem.ForeColor = e.Item.ListView.BackColor;
}
else if (e.Item.Selected && !e.Item.ListView.Focused)
{
e.SubItem.BackColor = SystemColors.Control;
e.SubItem.ForeColor = e.Item.ListView.ForeColor;
}
else
{
e.SubItem.BackColor = e.Item.ListView.BackColor;
e.SubItem.ForeColor = e.Item.ListView.ForeColor;
}
// Draw the standard header background.
e.DrawBackground();
//add a 2 pixel buffer the match default behavior
Rectangle rec = new Rectangle(e.Bounds.X + 2, e.Bounds.Y+2, e.Bounds.Width - 4, e.Bounds.Height-4);
//TODO Confirm combination of TextFormatFlags.EndEllipsis and TextFormatFlags.ExpandTabs works on all systems. MSDN claims they're exclusive but on Win7-64 they work.
TextFormatFlags flags = TextFormatFlags.Left | TextFormatFlags.EndEllipsis | TextFormatFlags.ExpandTabs | TextFormatFlags.SingleLine;
//If a different tabstop than the default is needed, will have to p/invoke DrawTextEx from win32.
TextRenderer.DrawText(e.Graphics, e.SubItem.Text, e.Item.ListView.Font, rec, e.SubItem.ForeColor, flags);
}