用 C# 實現截圖功能（三）：ScreenBody 滑鼠事件與截圖邏輯（下）

ScreenBody 關鍵事件處理

private void ScreenBody_DoubleClick(object sender, EventArgs e)
{
    var me = (MouseEventArgs)e;
    if (me.Button == MouseButtons.Left && myRectangle.Contains(me.X, me.Y))
    {
        panel1.Visible = false;
        MainPainter.DrawImage(baseImage, 0, 0);
        Image memory = new Bitmap(myRectangle.Width, myRectangle.Height);
        Graphics g = Graphics.FromImage(memory);
        g.CopyFromScreen(myRectangle.X, myRectangle.Y, 0, 0, myRectangle.Size);
        Clipboard.SetImage(memory);
        this.Close();
    }
}

private void ScreenBody_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        isDowned = true;
        if (!RectReady)
        {
            myRectangle.DownPointX = e.X;
            myRectangle.DownPointY = e.Y;
            myRectangle.X = e.X;
            myRectangle.Y = e.Y;
        }
        if (RectReady) moveModeDownPoint = new Point(e.X, e.Y);
    }
    if (e.Button == MouseButtons.Right)
    {
        if (!RectReady) { this.Close(); return; }
        MainPainter.DrawImage(baseImage, 0, 0);
        myRectangle.Initialize(0, 0, 0, 0);
        myRectangle.setAllModeFalse();
        this.Cursor = myRectangle.MyCursor;
        RectReady = false;
    }
}

private void ScreenBody_MouseUp(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left) { isDowned = false; RectReady = true; }
}

private void ScreenBody_MouseMove(object sender, MouseEventArgs e)
{
    labelWidth.Text = myRectangle.Width.ToString();
    labelHeight.Text = myRectangle.Height.ToString();
    labelLocation.Text = $"X {myRectangle.X}, Y {myRectangle.Y}";

    if (!RectReady)
    {
        if (isDowned) myRectangle.Draw(e, this.BackColor);
    }
    else
    {
        myRectangle.CheckMouseLocation(e);
        this.Cursor = myRectangle.MyCursor;
        changeSizeMode = myRectangle.ChangeSizeMode;
        moveMode = myRectangle.MoveMode && myRectangle.Contains(moveModeDownPoint.X, moveModeDownPoint.Y);
        if (changeSizeMode)
        {
            moveMode = false;
            myRectangle.Draw(BackColor);
            myRectangle.ChangeSize(e);
            myRectangle.Draw(BackColor);
        }
        if (moveMode)
        {
            changeSizeMode = false;
            myRectangle.Draw(BackColor);
            myRectangle.X += e.X - moveModeDownPoint.X;
            myRectangle.Y += e.Y - moveModeDownPoint.Y;
            moveModeDownPoint = new Point(e.X, e.Y);
            myRectangle.Draw(this.BackColor);
        }
    }
}

private void ScreenBody_Load(object sender, EventArgs e)
{
    this.WindowState = FormWindowState.Maximized;
    MainPainter = this.CreateGraphics();
    isDowned = false;
    baseImage = this.BackgroundImage;
    panel1.Visible = true;
    RectReady = false;
    changeSizeMode = false;
    moveMode = false;
}