C#中的WinForm问题——使用滚动条时页面闪烁及重影问题 C#中的WinForm问题——使用滚动条时页面闪烁及重影问题当使用鼠标进行滚动查看页面时，由于页面会频繁刷新，如果页面中控件较多会导致页面出现闪烁、重影等问题，如下图所示：具体的解决方案是通过设置CreateParams的ExStyle为ExStyle 为 0x02000000 （WS_EX_COMPOSITED）。protected override CreateParams CreateParams { get { CreateParams cp = base.CreateParams; cp.ExStyle |= 0x02000000; return cp; } }

WinForm系统托盘双击打开窗体 this.Visible = true; this.WindowState = FormWindowState.Normal;//双击打开窗体

WinForm关闭窗体时系统托盘不死 在窗体的FormClosing事件添加代码↓notifyIcon.Visible = false;//关闭系统托盘

WinForm播放mp3音频代码段 #region 播放音频 public class Mp3Player { //定义API函数使用的字符串变量 [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)] private string Name = ""; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)] private string durLength = ""; [MarshalAs(UnmanagedType.LPTStr, SizeConst = 128)] private string TemStr = ""; private int ilong; //定义播放状态枚举变量 public enum State { mPlaying = 1, mPuase = 2, mStop = 3 }; //结构变量 public struct structMCI { public bool bMut; public int iDur; public int iPos; public int iVol; public int iBal; public string iName; public State state; }; public structMCI mc = new structMCI(); //取得播放文件属性 public string FileName { get { return mc.iName; } set { //ASCIIEncoding asc = new ASCIIEncoding(); try { TemStr = ""; TemStr = TemStr.PadLeft(127, Convert.ToChar(" ")); Name = Name.PadLeft(260, Convert.ToChar(" ")); mc.iName = value; ilong = APIClass.GetShortPathName(mc.iName, Name, Name.Length); Name = GetCurrPath(Name); //Name = "open " + Convert.ToChar(34) + Name + Convert.ToChar(34) + " alias media"; Name = "open " + Convert.ToChar(34) + Name + Convert.ToChar(34) + " alias media"; ilong = APIClass.mciSendString("close all", TemStr, TemStr.Length, 0); ilong = APIClass.mciSendString(Name, TemStr, TemStr.Length, 0); ilong = APIClass.mciSendString("set media time format milliseconds", TemStr, TemStr.Length, 0); mc.state = State.mStop; } catch { } } } //播放 public void play() { TemStr = ""; TemStr = TemStr.PadLeft(127, Convert.ToChar(" ")); APIClass.mciSendString("play media", TemStr, TemStr.Length, 0); mc.state = State.mPlaying; } //停止 public void StopT() { TemStr = ""; TemStr = TemStr.PadLeft(128, Convert.ToChar(" ")); ilong = APIClass.mciSendString("close media", TemStr, 128, 0); ilong = APIClass.mciSendString("close all", TemStr, 128, 0); mc.state = State.mStop; } public void Puase() { TemStr = ""; TemStr = TemStr.PadLeft(128, Convert.ToChar(" ")); ilong = APIClass.mciSendString("pause media", TemStr, TemStr.Length, 0); mc.state = State.mPuase; } private string GetCurrPath(string name) { if (name.Length < 1) return ""; name = name.Trim(); name = name.Substring(0, name.Length - 1); return name; } //总时间 public int Duration { get { durLength = ""; durLength = durLength.PadLeft(128, Convert.ToChar(" ")); APIClass.mciSendString("status media length", durLength, durLength.Length, 0); durLength = durLength.Trim(); if (durLength == "") return 0; return (int)(Convert.ToDouble(durLength) / 1000f); } } //当前时间 public int CurrentPosition { get { durLength = ""; durLength = durLength.PadLeft(128, Convert.ToChar(" ")); APIClass.mciSendString("status media position", durLength, durLength.Length, 0); mc.iPos = (int)(Convert.ToDouble(durLength) / 1000f); return mc.iPos; } } } public class APIClass { [DllImport("kernel32.dll", CharSet = CharSet.Auto)] public static extern int GetShortPathName( string lpszLongPath, string shortFile, int cchBuffer ); [DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Auto)] public static extern int mciSendString( string lpstrCommand, string lpstrReturnString, int uReturnLength, int hwndCallback ); } #endregion /* *下面的代码可以放到按钮控件内 /* #region 播放 Mp3Player mp3Play = new Mp3Player() { FileName = @"C:\ProgramData\User\music.mp3", }; mp3Play.play(); #endregion #region 暂停 Mp3Player mp3Play = new Mp3Player() { }; mp3Play.Puase(); #endregion

C# 实现类似QQ的窗体在桌面边缘停靠和隐藏 C# 实现类似QQ的窗体在桌面边缘停靠和隐藏设计思路： 1.使用定时器（Timer）来监控鼠标位置和窗体位置，并实现窗体的停靠和隐藏2.当鼠标拖动窗体时，窗体才有可能根据自身位置决定是否停靠3.如果窗体四周没有接触到屏幕边缘则不会停靠4.如果窗体最小化或最大化了则不存在停靠和隐藏5.如果鼠标拖动窗体时，如果窗体很接近屏幕边缘则自动将其停靠在该边缘，例如窗体离屏幕顶部小于4个像素则自动将其停靠在顶部6.窗体可以在桌面的左侧、右侧和顶部停靠和隐藏7.如果既满足顶部停靠的条件又满足侧面停靠的条件，则规定其向侧面隐藏8.当鼠标位于窗体内部时，窗体不会隐藏9.当鼠标位于窗体外部，窗体根据自身的位置决定是否隐藏10.所谓的隐藏实际上并不是真正的隐藏，而是将整个窗体移出屏幕，仅在屏幕边缘留出一小部分11.所谓的显示隐藏窗体实际上并不是真正的显示，而是将窗体再次移入屏幕12.（存在的问题）默认情况下当用户点击“显示桌面”，会使我们隐藏的窗体被最小化。显然这并不是我们想要的结果，该问题暂时保留效果显示： private void timer1_Tick(object sender, EventArgs e) { timer1.Interval = 200; AutoSideHideOrShow(); } void AutoSideHideOrShow() { int sideThickness = 4;//边缘的厚度，窗体停靠在边缘隐藏后留出来的可见部分的厚度 //如果窗体最小化或最大化了则什么也不做 if (this.WindowState == FormWindowState.Minimized || this.WindowState == FormWindowState.Maximized) { return; } //如果鼠标在窗体内 if (Cursor.Position.X >= this.Left && Cursor.Position.X < this.Right && Cursor.Position.Y >= this.Top && Cursor.Position.Y < this.Bottom) { //如果窗体离屏幕边缘很近，则自动停靠在该边缘 if (this.Top <= sideThickness) { this.Top = 0; } if (this.Left <= sideThickness) { this.Left = 0; } if (this.Left >= Screen.PrimaryScreen.WorkingArea.Width - this.Width - sideThickness) { this.Left = Screen.PrimaryScreen.WorkingArea.Width - this.Width; } } //当鼠标离开窗体以后 else { //隐藏到屏幕左边缘 if (this.Left == 0) { this.Left = sideThickness - this.Width; } //隐藏到屏幕右边缘 else if (this.Left == Screen.PrimaryScreen.WorkingArea.Width - this.Width) { this.Left = Screen.PrimaryScreen.WorkingArea.Width - sideThickness; } //隐藏到屏幕上边缘 else if (this.Top == 0 && this.Left > 0 && this.Left < Screen.PrimaryScreen.WorkingArea.Width - this.Width) { this.Top = sideThickness - this.Height; } } }

Winform向服务器请求图片 图片控件.ImageLocation = @图片地址;

Winform通过ping baidu.com 检测网络 Ping pingSender = new Ping(); PingReply reply = null; try { reply = pingSender.Send("www.baidu.com", 1000); //if判断是否可以连接网站 } catch (Exception) { } finally { if (reply == null || (reply != null && reply.Status != IPStatus.Success)) {//网络连接失败 } else {//网络正常 if (reply.Status == IPStatus.Success) //if判断网络正常状态 { } } }

winform窗体透明背景实现 因为winform Form窗体的局限性，不允许设置背景色为transparent。所以不能实现透明背景。这里有一个取巧的方法（截Form后的背景）。首先来看下实现效果： 想要实现半透明效果只要加个panel ,将panel设置为背景色透明，然后加个遮罩图片就可以了。 以下附上实现代码：using System; using System.Drawing; using System.Windows.Forms; namespace WindowsTrans { public partial class Form1 : Form { private Color tr_color = Color.Transparent; private bool b_start = false; bool[] b_visible = null; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { SetBackgroundImageTransparent(); } private void SetBackgroundImageTransparent() { Point pt = this.PointToScreen(new Point(0, 0)); Bitmap b = new Bitmap(this.Width, this.Height); using (Graphics g = Graphics.FromImage(b)) { g.CopyFromScreen(pt, new Point(), new Size(this.Width, this.Height)); } this.BackgroundImage = b; } private void BeginSet() { tr_color = this.TransparencyKey; b_start = true; } private void Setting() { if (b_start) { b_visible = new bool[Controls.Count]; for (int i = 0; i < Controls.Count; i++) { b_visible[i] = Controls[i].Visible; Controls[i].Visible = false; } BackgroundImage = null; BackColor = Color.White; b_start = false; this.TransparencyKey = Color.White; } } private void EndSet() { SetBackgroundImageTransparent(); this.TransparencyKey = tr_color; for (int i = 0; i < Controls.Count; i++) { Controls[i].Visible = b_visible[i]; } b_start = false; } private void Form1_Resize(object sender, EventArgs e) { Setting(); } private void Form1_ResizeBegin(object sender, EventArgs e) { BeginSet(); } private void Form1_ResizeEnd(object sender, EventArgs e) { EndSet(); } private void Form1_Move(object sender, EventArgs e) { Setting(); } } }

C# 中的除法运算 %"为取余号。"/"号做什么运算与除数和被除数的类型有关整形运算是取整（不进行四舍五入只取整数部分） int a = 4; int b = 5; float c = a / b; Console.WriteLine(c); Console.ReadKey();结果为c=0（因为会先进行int的除法操作,得出结果0,再将结果转为float 0;）；2.浮点运算时为除法运算 float a = 4; float b = 5; float c = a / b; Console.WriteLine(c); Console.ReadKey();结果 c=0.8Math.Celling()取整数的较大数，相当于不管余数是什么都会进一位。如Math.Celling(54.0/10.0)结果为6.Math.Floor()取整数的较小数，相当于"/"号，即不管余数部分是什么都不进行进位。如Math.Floor(56.0/10.0)的结果是5.