不传任何参数得到窗体对象实例(C#)

1using System;

2using System.Drawing;

3using System.Collections;

4using System.ComponentModel;

5using System.Windows.Forms;

6using System.Data;

7using System.Runtime.InteropServices;

8

9namespace Demo

10{

11      publicclass NativeWin32

12      {

13             public NativeWin32()

14             {

15

16             }

17

18             publicdelegatebool CallBackFunction(IntPtr hwnd, IntPtr lParam);

19

20             [DllImport("user32.dll", CharSet=CharSet.Auto)]

21             publicstaticextern IntPtr FindWindow(string lpClassName,

22                     string lpWindowName);

23

24             [DllImport("user32.dll", CharSet=CharSet.Auto)]

25            publicstaticexternbool EnumThreadWindows(int threadId, CallBackFunction funPtr, IntPtr lParam);

26      }

27

28      publicclass Form1 : System.Windows.Forms.Form

29      {

30             private System.Windows.Forms.Button btnMethod1;

31             private System.Windows.Forms.Button btnMethod2;

32             private System.Windows.Forms.Button btnMethod3;

33             private System.Windows.Forms.Button btnMethod4;

34             private System.Windows.Forms.Button btnMethod5;

35

36             private System.ComponentModel.Container components = null;

37

38             public Form1()

39             {

40                     InitializeComponent();

41             }

42

43             protectedoverridevoid Dispose( bool disposing )

44             {

45                     if( disposing )

46                     {

47                             if (components != null)

48                             {

49                                    components.Dispose();

50                             }

51                     }

52                     base.Dispose( disposing );

53             }

54

55             privatevoid InitializeComponent()

56             {

57                     this.btnMethod1 = new System.Windows.Forms.Button();

58                     this.btnMethod2 = new System.Windows.Forms.Button();

59                     this.btnMethod3 = new System.Windows.Forms.Button();

60                     this.btnMethod4 = new System.Windows.Forms.Button();

61                     this.btnMethod5 = new System.Windows.Forms.Button();

62                     this.SuspendLayout();

63                     //

64                     // btnMethod1

65                     //

66                     this.btnMethod1.Location = new System.Drawing.Point(56, 24);

67                     this.btnMethod1.Name = "btnMethod1";

68                     this.btnMethod1.Size = new System.Drawing.Size(72, 32);

69                     this.btnMethod1.TabIndex = 0;

70                     this.btnMethod1.Text = "Method1";

71                     this.btnMethod1.Click += new System.EventHandler(this.btnMethod1_Click);

72                     //

73                     // btnMethod2

74                     //

75                     this.btnMethod2.Location = new System.Drawing.Point(176, 24);

76                     this.btnMethod2.Name = "btnMethod2";

77                     this.btnMethod2.Size = new System.Drawing.Size(72, 32);

78                     this.btnMethod2.TabIndex = 1;

79                     this.btnMethod2.Text = "Method2";

80                     this.btnMethod2.Click += new System.EventHandler(this.btnMethod2_Click);

81                     //

82                     // btnMethod3

83                     //

84                     this.btnMethod3.Location = new System.Drawing.Point(56, 80);

85                     this.btnMethod3.Name = "btnMethod3";

86                     this.btnMethod3.Size = new System.Drawing.Size(72, 32);

87                     this.btnMethod3.TabIndex = 2;

88                     this.btnMethod3.Text = "Method3";

89                     this.btnMethod3.Click += new System.EventHandler(this.btnMethod3_Click);

90                     //

91                     // btnMethod4

92                     //

93                     this.btnMethod4.Location = new System.Drawing.Point(176, 80);

94                     this.btnMethod4.Name = "btnMethod4";

95                     this.btnMethod4.Size = new System.Drawing.Size(72, 32);

96                     this.btnMethod4.TabIndex = 3;

97                     this.btnMethod4.Text = "Method4";

98                     this.btnMethod4.Click += new System.EventHandler(this.btnMethod4_Click);

99                     //

100                    // btnMethod5

101                    //

102                    this.btnMethod5.Location = new System.Drawing.Point(120, 136);

103                    this.btnMethod5.Name = "btnMethod5";

104                    this.btnMethod5.Size = new System.Drawing.Size(72, 32);

105                    this.btnMethod5.TabIndex = 4;

106                    this.btnMethod5.Text = "Method5";

107                    this.btnMethod5.Click += new System.EventHandler(this.btnMethod5_Click);

108                    //

109                    // Form1

110                    //

111                    this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);

112                    this.ClientSize = new System.Drawing.Size(320, 189);

113                    this.Controls.Add(this.btnMethod5);

114                    this.Controls.Add(this.btnMethod4);

115                    this.Controls.Add(this.btnMethod3);

116                    this.Controls.Add(this.btnMethod2);

117                    this.Controls.Add(this.btnMethod1);

118                    this.MaximizeBox = false;

119                    this.Name = "Form1";

120                    this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;

121                    this.Text = "Demo";

122                    this.ResumeLayout(false);

123

124            }

125            #endregion

126

127            [STAThread]

128            staticvoid Main()

129            {

130                    Application.Run(new Form1());

131            }

132

133            privatevoid btnMethod1_Click(object sender, System.EventArgs e)

134            {

135                    System.IntPtr hwnd = NativeWin32.FindWindow(null,"Demo");

136                    Form1 form = System.Windows.Forms.Form.FromHandle(hwnd) as Form1;

137                    MessageBox.Show((null != form ? "Success!" : "Failure"),"Method1");

138            }

139

140            privatevoid btnMethod2_Click(object sender, System.EventArgs e)

141            {

142                    System.Diagnostics.Process process = System.Diagnostics.Process.GetCurrentProcess();

143                    System.IntPtr hwnd = process.MainWindowHandle;

144                    Form1 form = System.Windows.Forms.Form.FromHandle(hwnd) as Form1;

145                    MessageBox.Show((null != form ? "Success!" : "Failure"),"Method2");

146

147            }

148

149            privatebool _isFind = false;

150            privatevoid btnMethod3_Click(object sender, System.EventArgs e)

151            {

152

153                    System.Diagnostics.Process process = System.Diagnostics.Process.GetCurrentProcess();

154

155                    foreach (System.Diagnostics.ProcessThread thread in process.Threads)

156                    {

157                            _isFind = false;

158                            NativeWin32.CallBackFunction callBackFun = new NativeWin32.CallBackFunction(CallBackMethod);

159                            NativeWin32.EnumThreadWindows(thread.Id,callBackFun,IntPtr.Zero);

160

161                            if (_isFind)

162                            {

163                                   MessageBox.Show("Success!","Method3");

164                                   break;

165                            }

166                    }

167

168                    if (!_isFind) MessageBox.Show("Failure!","Method3");

169            }

170

171           

172            privatevoid btnMethod4_Click(object sender, System.EventArgs e)

173            {

174                   

175                    _isFind = false;

176                    NativeWin32.CallBackFunction callBackFun = new NativeWin32.CallBackFunction(CallBackMethod);

177

178                    NativeWin32.EnumThreadWindows(AppDomain.GetCurrentThreadId(),callBackFun,IntPtr.Zero);

179

180                    MessageBox.Show((_isFind ? "Success!" : "Failure"),"Method4");

181            }

182

183            privatevoid btnMethod5_Click(object sender, System.EventArgs e)

184            {

185                    MessageBox.Show(".Net 2.0 Usage/r/nSystem.Windows.Forms.Application.OpenForms[/"Form1/"]","Method5");

186            }

187

188            privatebool CallBackMethod(IntPtr hwnd, IntPtr lParam)

189            {

190                    Form1 form = System.Windows.Forms.Form.FromHandle(hwnd) as Form1;

191                    if (null != form) _isFind = true;

192                    returntrue;

193            }

194

195     }

196}