c# - 用户如何在运行时在 Winforms 中调整控件大小

Question

说我有一个图片框。

现在我想要的是用户应该能够随意调整图片框的大小。但是我不知道如何开始这件事。我已经搜索过互联网，但信息很少。

谁能至少指导我从哪里开始？

Answer 1

这很容易做到，Windows 中的每个窗口都具有可调整大小的先天能力。它只是为 PictureBox 关闭，您可以通过侦听WM_NCHITTEST 消息将其重新打开。您只需告诉 Windows 光标位于窗口的一角，您就可以免费获得其他所有内容。您还需要绘制一个把手，以便用户清楚地知道拖动角将调整框的大小。

向您的项目添加一个新类并粘贴如下所示的代码。构建+构建。您将在工具箱顶部获得一个新控件，将其放在表单上。设置 Image 属性，您就可以尝试了。

using System;
using System.Drawing;
using System.Windows.Forms;

class SizeablePictureBox : PictureBox {
    public SizeablePictureBox() {
        this.ResizeRedraw = true;
    }
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        var rc = new Rectangle(this.ClientSize.Width - grab, this.ClientSize.Height - grab, grab, grab);
        ControlPaint.DrawSizeGrip(e.Graphics, this.BackColor, rc); 
    }
    protected override void WndProc(ref Message m) {
        base.WndProc(ref m);
        if (m.Msg == 0x84) {  // Trap WM_NCHITTEST
            var pos = this.PointToClient(new Point(m.LParam.ToInt32()));
            if (pos.X >= this.ClientSize.Width - grab && pos.Y >= this.ClientSize.Height - grab)
                m.Result = new IntPtr(17);  // HT_BOTTOMRIGHT
        }
    }
    private const int grab = 16;
}

另一种免费调整大小的非常便宜的方法是为控件提供可调整大小的边框。它适用于所有角落和边缘。将此代码粘贴到类中（您不再需要 WndProc）：

protected override CreateParams CreateParams {
    get {
        var cp = base.CreateParams;
        cp.Style |= 0x840000;  // Turn on WS_BORDER + WS_THICKFRAME
        return cp;
    }
}

Answer 2

with use ControlMoverOrResizer class in this article you can do movable and resizable controls in run time just with a line of code! :) example:

ControlMoverOrResizer.Init(button1);

and now button1 is a movable and resizable control!

Answer 3

这是一篇文章

http://www.codeproject.com/Articles/20716/Allow-the-User-to-Resize-Controls-at-Runtime

这应该对您有所帮助，因为它在 vb 中是 C# 翻译

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class Form1
{


    ResizeableControl rc;

    private void Form1_Load(System.Object sender, System.EventArgs e)
    {
        rc = new ResizeableControl(pbDemo);

    }
    public Form1()
    {
        Load += Form1_Load;
    }

}

和调整大小功能

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class ResizeableControl
{

    private Control withEventsField_mControl;
    private Control mControl {
        get { return withEventsField_mControl; }
        set {
            if (withEventsField_mControl != null) {
                withEventsField_mControl.MouseDown -= mControl_MouseDown;
                withEventsField_mControl.MouseUp -= mControl_MouseUp;
                withEventsField_mControl.MouseMove -= mControl_MouseMove;
                withEventsField_mControl.MouseLeave -= mControl_MouseLeave;
            }
            withEventsField_mControl = value;
            if (withEventsField_mControl != null) {
                withEventsField_mControl.MouseDown += mControl_MouseDown;
                withEventsField_mControl.MouseUp += mControl_MouseUp;
                withEventsField_mControl.MouseMove += mControl_MouseMove;
                withEventsField_mControl.MouseLeave += mControl_MouseLeave;
            }
        }
    }
    private bool mMouseDown = false;
    private EdgeEnum mEdge = EdgeEnum.None;
    private int mWidth = 4;

    private bool mOutlineDrawn = false;
    private enum EdgeEnum
    {
        None,
        Right,
        Left,
        Top,
        Bottom,
        TopLeft
    }

    public ResizeableControl(Control Control)
    {
        mControl = Control;
    }


    private void mControl_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.Left) {
            mMouseDown = true;
        }
    }


    private void mControl_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        mMouseDown = false;
    }


    private void mControl_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        Control c = (Control)sender;
        Graphics g = c.CreateGraphics;
        switch (mEdge) {
            case EdgeEnum.TopLeft:
                g.FillRectangle(Brushes.Fuchsia, 0, 0, mWidth * 4, mWidth * 4);
                mOutlineDrawn = true;
                break;
            case EdgeEnum.Left:
                g.FillRectangle(Brushes.Fuchsia, 0, 0, mWidth, c.Height);
                mOutlineDrawn = true;
                break;
            case EdgeEnum.Right:
                g.FillRectangle(Brushes.Fuchsia, c.Width - mWidth, 0, c.Width, c.Height);
                mOutlineDrawn = true;
                break;
            case EdgeEnum.Top:
                g.FillRectangle(Brushes.Fuchsia, 0, 0, c.Width, mWidth);
                mOutlineDrawn = true;
                break;
            case EdgeEnum.Bottom:
                g.FillRectangle(Brushes.Fuchsia, 0, c.Height - mWidth, c.Width, mWidth);
                mOutlineDrawn = true;
                break;
            case EdgeEnum.None:
                if (mOutlineDrawn) {
                    c.Refresh();
                    mOutlineDrawn = false;
                }
                break;
        }

        if (mMouseDown & mEdge != EdgeEnum.None) {
            c.SuspendLayout();
            switch (mEdge) {
                case EdgeEnum.TopLeft:
                    c.SetBounds(c.Left + e.X, c.Top + e.Y, c.Width, c.Height);
                    break;
                case EdgeEnum.Left:
                    c.SetBounds(c.Left + e.X, c.Top, c.Width - e.X, c.Height);
                    break;
                case EdgeEnum.Right:
                    c.SetBounds(c.Left, c.Top, c.Width - (c.Width - e.X), c.Height);
                    break;
                case EdgeEnum.Top:
                    c.SetBounds(c.Left, c.Top + e.Y, c.Width, c.Height - e.Y);
                    break;
                case EdgeEnum.Bottom:
                    c.SetBounds(c.Left, c.Top, c.Width, c.Height - (c.Height - e.Y));
                    break;
            }
            c.ResumeLayout();
        } else {
            switch (true) {
                case e.X <= (mWidth * 4) & e.Y <= (mWidth * 4):
                    //top left corner
                    c.Cursor = Cursors.SizeAll;
                    mEdge = EdgeEnum.TopLeft;
                    break;
                case e.X <= mWidth:
                    //left edge
                    c.Cursor = Cursors.VSplit;
                    mEdge = EdgeEnum.Left;
                    break;
                case e.X > c.Width - (mWidth + 1):
                    //right edge
                    c.Cursor = Cursors.VSplit;
                    mEdge = EdgeEnum.Right;
                    break;
                case e.Y <= mWidth:
                    //top edge
                    c.Cursor = Cursors.HSplit;
                    mEdge = EdgeEnum.Top;
                    break;
                case e.Y > c.Height - (mWidth + 1):
                    //bottom edge
                    c.Cursor = Cursors.HSplit;
                    mEdge = EdgeEnum.Bottom;
                    break;
                default:
                    //no edge
                    c.Cursor = Cursors.Default;
                    mEdge = EdgeEnum.None;
                    break;
            }
        }
    }


    private void mControl_MouseLeave(object sender, System.EventArgs e)
    {
        Control c = (Control)sender;
        mEdge = EdgeEnum.None;
        c.Refresh();
    }

}

Answer 4

创建一个新的 c# winform 应用程序并粘贴：

帮到你的时候别忘了说声谢谢...

http://www.codeproject.com/script/Articles/ArticleVersion.aspx?aid=743923&av=1095793&msg=4778687

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

namespace WindowsFormsApplication1
  {
 public partial class MyForm : Form
  {
    //Public Declaration:
    double rW = 0;
    double rH = 0;

    int fH = 0;
    int fW = 0;


    // @ Form Initialization
    public MyForm()
    {
        InitializeComponent();
        this.Resize += MyForm_Resize; // handles resize routine
        this.tabControl1.Dock = DockStyle.None;

    }


    private void MyForm_Resize(object sender, EventArgs e)
    {
        rResize(this,true); //Call the routine

    }

    private void rResize(Control t, bool hasTabs) // Routine to Auto resize the control
    {

        // this will return to normal default size when 1 of the conditions is met

        string[] s = null;

        if (this.Width < fW || this.Height < fH)
        {

            this.Width = (int)fW;
            this.Height = (int)fH;

            return;
        }

        foreach (Control c in t.Controls)
        {
            // Option 1:
            double rRW = (t.Width > rW ? t.Width / (rW) : rW / t.Width);
            double rRH = (t.Height > rH ? t.Height / (rH) : rH / t.Height);

            // Option 2:
            //  double rRW = t.Width / rW;
            //  double rRH = t.Height / rH;

            s = c.Tag.ToString().Split('/');
            if (c.Name == s[0].ToString())
            {
                //Use integer casting
                c.Width = (int)(Convert.ToInt32(s[3]) * rRW);
                c.Height = (int)(Convert.ToInt32(s[4]) * rRH);
                c.Left = (int)(Convert.ToInt32(s[1]) * rRW);
                c.Top = (int)(Convert.ToInt32(s[2]) * rRH);
            }
            if (hasTabs)
            {
                if (c.GetType() == typeof(TabControl))
                {

                    foreach (Control f in c.Controls)
                    {
                        foreach (Control j in f.Controls) //tabpage
                        {
                            s = j.Tag.ToString().Split('/');

                            if (j.Name == s[0].ToString())
                            {

                                j.Width = (int)(Convert.ToInt32(s[3]) * rRW);
                                j.Height = (int)(Convert.ToInt32(s[4]) * rRH);
                                j.Left = (int)(Convert.ToInt32(s[1]) * rRW);
                                j.Top = (int)(Convert.ToInt32(s[2]) * rRH);
                            }
                        }
                    }
                }
            }

        }
    }

    // @ Form Load Event
    private void MyForm_Load(object sender, EventArgs e)
    {


        // Put values in the variables

        rW = this.Width;
        rH = this.Height;

        fW = this.Width;
        fH = this.Height;


        // Loop through the controls inside the  form i.e. Tabcontrol Container
        foreach (Control c in this.Controls)
        {
            c.Tag = c.Name + "/" + c.Left + "/" + c.Top + "/" + c.Width + "/" + c.Height;

            // c.Anchor = (AnchorStyles.Right |  AnchorStyles.Left ); 

            if (c.GetType() == typeof(TabControl))
            {

                foreach (Control f in c.Controls)
                {

                    foreach (Control j in f.Controls) //tabpage
                    {
                        j.Tag = j.Name + "/" + j.Left + "/" + j.Top + "/" + j.Width + "/" + j.Height;
                    }
                }
            }
        }
    }
}
}

问候， Kix46

Answer 5

namespace utils
{
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data;
using System.Globalization;
using System.Xml;
using System.Text.RegularExpressions;
using System.Drawing;
public static class Helper
{
    public const int WM_NCLBUTTONDOWN = 0xA1;
    public const int HTCAPTION = 2;
    public static int WS_THICKFRAME = 0x00040000;
    public static int GWL_STYLE = -16;
    public static int GWL_EXSTYLE = -20;
    public static int WS_EX_LAYERED = 0x00080000;
    public const int WS_RESIZABLE = 0x840000; //WS_BORDER + WS_THICKFRAME

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    static extern bool AppendMenu(IntPtr hMenu, uint uFlags, uint uIDNewItem, string lpNewItem);

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    public static extern int GetWindowLong(IntPtr hWnd, int nIndex);

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    public static extern int
    SetLayeredWindowAttributes(IntPtr Handle, int Clr, byte transparency, int clrkey);

    [System.Runtime.InteropServices.DllImport("shell32.dll")]
    public static extern IntPtr ShellExecute(IntPtr hwnd, string lpOperation, string lpFile, string lpParameters, string lpDirectory, int nShowCmd);

    [return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
    [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true)]
    public static extern bool PostMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);

    [System.Runtime.InteropServices.DllImport("kernel32.dll")]
    public static extern uint GetCurrentThreadId();
    public static string ProcessException(this Exception ex)
    {
        StringBuilder strBuild = new StringBuilder(5000);
        Exception inner = ex;
        Enumerable.Range(0, 30).All(x =>
        {
            if (x == 0) strBuild.Append("########## Exception begin on thread id : " + GetCurrentThreadId().ToString() + " @ :" + DateTime.Now.ToString() + " ##########\n");
            strBuild.Append("---------------------[" + x.ToString() + "]---------------------\n");
            strBuild.Append("Message : " + inner.Message + "\nStack Trace : " + inner.StackTrace + "\n");
            strBuild.Append("---------------------[" + x.ToString() + "]---------------------\n");
            inner = inner.InnerException;
            if (inner == null)
            {
                strBuild.Append("########## Exception End on thread id : " + GetCurrentThreadId().ToString() + " @ :" + DateTime.Now.ToString() + " ##########\n\n");
                return false;
            }
            return true;
        });
        return strBuild.ToString();
    }
   
   public static void MakeResizable(this Panel pnl)
    {
        int dwCurStyle = Helper.GetWindowLong(pnl.Handle, GWL_STYLE);
        dwCurStyle = dwCurStyle | Helper.WS_RESIZABLE;
        Helper.SetWindowLong(pnl.Handle, GWL_STYLE, dwCurStyle);
    }
}

 protected override void OnLoad(EventArgs e)
    {
        imagePanel.MakeResizable();
        base.OnLoad(e);            
    }

其中 imgPanel 是 WinForm 应用程序中的某个面板