更新1

Question

我正在构建一个Windows表单应用程序，我有一个用于搜索目的的文本框。

我想在文本框右侧或左侧放置一个搜索图标

像这样：

enter image description here

我更喜欢正确的

更新1

我问的是Windows表单不是ASP.net或MVC

Answer 1

您可以使用Panel，TextBox和PictureBox。

enter image description here

TextBox必须放在面板中，这样您就无法在搜索图片上书写。

Answer 2

您可以创建一个新的UserControl来完成所需的工作。您必须为此扩展TextBox类。请看下面的代码：

    public class IconTextBox : System.Windows.Forms.TextBox
    {
        public IconTextBox() : base() { SetStyle(System.Windows.Forms.ControlStyles.UserPaint, true); this.Multiline = true; }

        public System.Drawing.Bitmap BitmapImage
        {
            set;
            get;
        }

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            base.OnPaint(e);
            System.Drawing.Image img = BitmapImage as System.Drawing.Image;
            e.Graphics.DrawImage(img, new System.Drawing.Point(this.Width - (img.Width), 0));

        }

    }

在OnPaint方法中，您可以指定图像。您也可以将其扩展为具有可以作为图像路径的自定义属性。你的选择。

Answer 3

按照Atanas的回答，我发现以下内容效果很好。可以设置CancelSearchImage和public class SearchTextBox : TextBox { private const int EM_SETMARGINS = 0xd3; [System.Runtime.InteropServices.DllImport("user32.dll")] private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp); private PictureBox searchPictureBox; private Button cancelSearchButton; public SearchTextBox() { cancelSearchButton = new Button(); cancelSearchButton.Anchor = AnchorStyles.Top | AnchorStyles.Right; cancelSearchButton.Size = new Size(16, 16); cancelSearchButton.TabIndex = 0; cancelSearchButton.TabStop = false; cancelSearchButton.FlatStyle = FlatStyle.Flat; cancelSearchButton.FlatAppearance.BorderSize = 0; cancelSearchButton.Text = ""; cancelSearchButton.Cursor = Cursors.Arrow; Controls.Add(cancelSearchButton); cancelSearchButton.Click += delegate { Text = ""; Focus(); }; searchPictureBox = new PictureBox(); searchPictureBox.Anchor = AnchorStyles.Top | AnchorStyles.Right; searchPictureBox.Size = new Size(16, 16); searchPictureBox.TabIndex = 0; searchPictureBox.TabStop = false; Controls.Add(searchPictureBox); // Send EM_SETMARGINS to prevent text from disappearing underneath the button SendMessage(Handle, EM_SETMARGINS, (IntPtr)2, (IntPtr)(16 << 16)); UpdateControlsVisibility(); } protected override void OnTextChanged(EventArgs e) { base.OnTextChanged(e); UpdateControlsVisibility(); } private void UpdateControlsVisibility() { if (string.IsNullOrEmpty(Text)) { cancelSearchButton.Visible = false; searchPictureBox.Visible = true; } else { cancelSearchButton.Visible = true; searchPictureBox.Visible = false; } } [Browsable(true)] public Image SearchImage { set { searchPictureBox.Image = value; searchPictureBox.Left = Width - searchPictureBox.Size.Width - 4; searchPictureBox.Top = Height - searchPictureBox.Size.Height - 4; } get { return searchPictureBox.Image; } } [Browsable(true)] public Image CancelSearchImage { set { cancelSearchButton.Image = value; cancelSearchButton.Left = Width - searchPictureBox.Size.Width - 4; cancelSearchButton.Top = Height - searchPictureBox.Size.Height - 4; } get { return cancelSearchButton.Image; } } }属性来控制使用的图像。

ProcessUser

Answer 4

使用用户控件或每次要执行此操作时添加代码都会非常麻烦。我处理这个的方法是添加一个初始化类，可以在运行时从我的表单中调用它。此代码的行为是当用户开始键入时，图像消失。如果文本框没有内容，则显示图像。我处理图片框的click事件以将焦点设置到文本框以保留它是控件的一部分的错觉，并偏移左边以允许|显示文本框具有焦点并准备好接收输入。

通过编写控制器而不是用户控件，我可以避免通过用户控件从文本框传播所有事件和属性。此类依赖于System.Windows.Forms，可以直接包含在Windows窗体应用程序中，也可以添加到可以从多个应用程序调用的控件库中。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing;

namespace WindowsFormsApplication1
{
    class TextBoxIcon
    {
        public static TextBoxIcon AddIcon(TextBox textbox, Image icon)
        {
            if (icon != null) {
                return new TextBoxIcon(textbox, icon);
            } else {
                return null;
            }
        }

        private TextBox _TextBox;
        private PictureBox _PictureBox;

        private TextBoxIcon(TextBox textbox, Image icon) {
            this._TextBox = textbox;
            this._PictureBox = new PictureBox();
            this._PictureBox.BackColor = textbox.BackColor;
            this._PictureBox.Image = ScaleImage(icon);
            this._TextBox.Parent.Controls.Add(_PictureBox);
            this._PictureBox.Location = new Point(textbox.Left + 5, textbox.Top + 2);
            this._PictureBox.Size = new Size(textbox.Width - 10, textbox.Height - 4);
            this._PictureBox.Anchor = textbox.Anchor;
            this._PictureBox.Visible = _TextBox.Visible;
            this._PictureBox.BringToFront();
            textbox.Resize += TextBox_Resize;
            textbox.TextChanged += TextBox_TextChanged;
            textbox.Leave += TextBox_Leave;
            _PictureBox.Click +=  PictureBox_Click;
            textbox.VisibleChanged += TextBox_VisibleChanged;
        }

        public static Image ScaleImage(Image img) {
            if (img.Height == 16) {
                return img;
            } else {
                return new Bitmap(img, new Size((int)((img.Height / 16.0) * img.Width), 16));
            }
        }

        private void TextBox_Resize(Object sender, EventArgs e) {
            _PictureBox.Size = new Size(_TextBox.Width - 10, _TextBox.Height - 4);
        }

        private void TextBox_VisibleChanged(Object sender, EventArgs e) {
            _PictureBox.Visible = _TextBox.Visible;
        }

        private void ShowPictureBox() {
            _PictureBox.Visible = String.IsNullOrEmpty(_TextBox.Text);
        }

        private void TextBox_TextChanged(Object sender, EventArgs e) {
            ShowPictureBox();
        }

        private void TextBox_Leave(Object sender, EventArgs e) {
            ShowPictureBox();
        }

        public void PictureBox_Click(object sender, EventArgs e) { 
            _TextBox.Focus();
        }
    }
}

以下是从表单中使用类的方法：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            TextBoxIcon.AddIcon(txtSearch, Properties.Resources.search);
        }
    }
}

只要文本框存在且已添加到表单中，就可以随时进行调用。

Answer 5

我建议使用RichTextBox代替TextBox。您可以在表单的加载中设置BackgroundImage property：

public Form1()
        {
            InitializeComponent();
            richTextBox1.BackgroundImage = Image.FromFile("image path");
        }

您必须添加TextChanged和leave等事件的处理才能显示和隐藏背景图片

windows形成如何在文本框的右侧或左侧添加图标

更新1

5 个答案: