[C#]Set Windows 7 Progress Bar's State

要在Win7設定Progressbar的運行狀態，可能是一般運行狀態，可能是暫停狀態，或是錯誤狀態。

我們可以透過SendMessage發送PBM_SETSTATE訊息給ProgressBar，訊息的wParam依需求可帶入PBST_NORMAL、PBST_ERROR、與PBST_PAUSED，lParam部分則帶入0就可以了。

程式撰寫起來會像下面這樣：

    #region Const
    const int PBM_SETSTATE = 0x410;
    const int PBST_PAUSE = 0x0003;
    const int PBST_ERROR = 0x0002;
    const int PBST_NORMAL = 0x0001;
    #endregion

    #region DllImport
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    internal static extern int SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam); 
    #endregion

    #region Private Method
    void SetPaused(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_PAUSE, 0);
    }

    void SetError(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_ERROR, 0);
    }

    void SetNormal(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_NORMAL, 0);
    } 
    #endregion

這邊用此概念做個簡單的示意範例：

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

namespace WindowsFormsApplication3 { public partial class Form1 : Form { #region Const const int PBM_SETPOS = 0x402; const int PBM_GETPOS = 0x0408; const int PBM_SETSTATE = 0x410; const int PBST_PAUSE = 0x0003; const int PBST_ERROR = 0x0002; const int PBST_NORMAL = 0x0001; #endregion

    #region DllImport
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    internal static extern int SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam); 
    #endregion

    #region Private Method
    void SetPaused(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_PAUSE, 0);
    }

    void SetError(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_ERROR, 0);
    }

    void SetNormal(ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_NORMAL, 0);
    } 
    #endregion

    public Form1()
    {
        InitializeComponent();
    }

    private void trackBar1_Scroll(object sender, EventArgs e)
    {
        SendMessage(progressBar1.Handle, PBM_SETPOS, trackBar1.Value, 0);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        SetNormal(progressBar1);
    }

    private void button2_Click(object sender, EventArgs e)
    {
        SetPaused(progressBar1);
    }

    private void button3_Click(object sender, EventArgs e)
    {
        SetError(progressBar1);
    }
}

}

當按下不同狀態按鈕，ProgressBar會有不同的呈現。

為了方便起見也可以將之整理成擴充方法。

public static class ProgressExtension
{
    #region Const
    const int PBM_SETSTATE = 0x410;
    const int PBST_PAUSE = 0x0003;
    const int PBST_ERROR = 0x0002;
    const int PBST_NORMAL = 0x0001;
    #endregion
    
    #region DllImport
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    internal static extern int SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam);
    #endregion

    #region Public Method
    public static void SetNormalState(this ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_NORMAL, 0);
    }

    public static void SetPauseState(this ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_PAUSE, 0);
    }

    public static void SetErrorState(this ProgressBar progressBar)
    {
        SendMessage(progressBar.Handle, PBM_SETSTATE, PBST_ERROR, 0);
    } 
    #endregion
}

使用上會更為方便簡潔。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void trackBar1_Scroll(object sender, EventArgs e)
    {
        progressBar1.Value = trackBar1.Value;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        progressBar1.SetNormalState();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        progressBar1.SetPauseState();
    }

    private void button3_Click(object sender, EventArgs e)
    {
        progressBar1.SetErrorState();
    }
}

Link

Windows 7 Progress Bars in .NET

PBM_SETSTATE message

Link#

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