Clipboard.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / Clipboard.cs / 1 / Clipboard.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 */ 
namespace System.Windows.Forms {
 
    using System;
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.Diagnostics; 
    using System.Drawing;
    using System.IO; 
    using System.Runtime.InteropServices; 
    using System.Runtime.InteropServices.ComTypes;
    using System.Security; 

    using IComDataObject = System.Runtime.InteropServices.ComTypes.IDataObject;
    using System.Globalization;
    using System.Security.Permissions; 
    using System.Collections;
 
    ///  
    /// 
    ///    Provides methods to place data on and retrieve data from the system clipboard. This class cannot be inherited. 
    /// 
    public sealed class Clipboard {

        // not creatable... 
        //
        private Clipboard() { 
        } 

        // 
        // Checks the validity of format while setting data into ClipBoard
        //
        private static bool IsFormatValid(DataObject data)
        { 
            string[] formats = data.GetFormats();
            Debug.Assert(formats != null, "Null returned from GetFormats"); 
            if (formats != null) 
            {
                if (formats.Length <= 4) 
                {
                    for (int i=0; i
        ///  
        /// Places nonpersistent data on the system .
        ///  
        public static void SetDataObject(object data) { 
            SetDataObject(data, false);
        } 

        /// 
        /// 
        /// Overload that uses default values for retryTimes and retryDelay. 
        /// 
        public static void SetDataObject(object data, bool copy) { 
            SetDataObject(data, copy, 10 /*retryTimes*/, 100 /*retryDelay*/); 
        }
 
        /// 
        /// 
        /// Places data on the system  and uses copy to specify whether the data
        ///    should remain on the  
        ///    after the application exits.
        ///  
        [UIPermission(SecurityAction.Demand, Clipboard=UIPermissionClipboard.OwnClipboard)] 
        public static void SetDataObject(object data, bool copy, int retryTimes, int retryDelay) {
            if (Application.OleRequired() != System.Threading.ApartmentState.STA) { 
                throw new System.Threading.ThreadStateException(SR.GetString(SR.ThreadMustBeSTA));
            }

            if (data == null) { 
                throw new ArgumentNullException("data");
            } 
 
            if (retryTimes < 0) {
                throw new ArgumentOutOfRangeException("retryTimes", SR.GetString(SR.InvalidLowBoundArgumentEx, "retryTimes", retryTimes.ToString(CultureInfo.CurrentCulture), (0).ToString(CultureInfo.CurrentCulture))); 
            }

            if (retryDelay < 0) {
                throw new ArgumentOutOfRangeException("retryDelay", SR.GetString(SR.InvalidLowBoundArgumentEx, "retryDelay", retryDelay.ToString(CultureInfo.CurrentCulture), (0).ToString(CultureInfo.CurrentCulture))); 
            }
 
 
            DataObject dataObject = null;
            if (!(data is IComDataObject)) { 
                dataObject = new DataObject(data);
            }

            bool restrictedFormats = false; 

            // If the caller doesnt have AllClipBoard permission then we allow only restricted formats. 
            // These formats are TEXT, UNICODETEXT,String and CSV 
            try
            { 
                IntSecurity.ClipboardRead.Demand();
            }
            catch (SecurityException)
            { 
                // We dont have allClipBoard so we can set only data in the following formats
                // TEXT, UNICODETEXT, and CSV. 
                restrictedFormats = true; 
            }
 
            // Compute the format of the "data" passed in iff setText == true;

            if (restrictedFormats)
            { 
                if (dataObject == null)
                { 
                    dataObject = data as DataObject; 
                }
                if (!IsFormatValid(dataObject)) 
                {
                    throw new SecurityException(SR.GetString(SR.ClipboardSecurityException));
                }
            } 

 
            int hr, retry = retryTimes; 

            IntSecurity.UnmanagedCode.Assert(); 

            try
            {
                do { 
                    if (data is IComDataObject) {
                        hr = UnsafeNativeMethods.OleSetClipboard((IComDataObject)data); 
                    } 
                    else {
                        hr = UnsafeNativeMethods.OleSetClipboard(dataObject); 
                    }
                    if (hr != 0) {
                        if (retry == 0) {
                            ThrowIfFailed(hr); 
                        }
                        retry--; 
                        System.Threading.Thread.Sleep(retryDelay /*ms*/); 
                    }
                } 
                while (hr != 0);

                if (copy) {
                    retry = retryTimes; 
                    do {
                        hr = UnsafeNativeMethods.OleFlushClipboard(); 
                        if (hr != 0) { 
                            if (retry == 0) {
                                ThrowIfFailed(hr); 
                            }
                            retry--;
                            System.Threading.Thread.Sleep(retryDelay /*ms*/);
                        } 
                    }
                    while (hr != 0); 
                } 
            }
            finally 
            {
                CodeAccessPermission.RevertAssert();
            }
        } 

        ///  
        ///  
        ///    Retrieves the data that is currently on the system
        ///    . 
        /// 
        public static IDataObject GetDataObject() {
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ClipboardRead Demanded");
            IntSecurity.ClipboardRead.Demand(); 

            if (Application.OleRequired() != System.Threading.ApartmentState.STA) { 
 
                // only throw if a message loop was started. This makes the case of trying
                // to query the clipboard from your finalizer or non-ui MTA thread 
                // silently fail, instead of making your app die.
                //
                // however, if you are trying to write a normal windows forms app and
                // forget to set the STAThread attribute, we will correctly report 
                // an error to aid in debugging.
                // 
                if (Application.MessageLoop) { 
                    throw new System.Threading.ThreadStateException(SR.GetString(SR.ThreadMustBeSTA));
                } 
                else {
                    return null;
                }
            } 
            // Vswhidbey :: 476911. We need to retry the GetDataObject() since the clipBaord is busy sometimes and hence the GetDataObject would fail with ClipBoardException.
            return GetDataObject(10 /*retryTimes*/, 100 /*retryDelay*/); 
        } 

        // Private method to help accessing clipBoard for know retries before failing. 
        private static IDataObject GetDataObject(int retryTimes, int retryDelay)
        {
            IComDataObject dataObject = null;
            int hr, retry = retryTimes; 
            do {
                hr = UnsafeNativeMethods.OleGetClipboard(ref dataObject); 
                if (hr != 0) { 
                    if (retry == 0) {
                        ThrowIfFailed(hr); 
                    }
                    retry--;
                    System.Threading.Thread.Sleep(retryDelay /*ms*/);
                } 
            }
            while (hr != 0); 
 
            if (dataObject != null) {
                if (dataObject is IDataObject && !Marshal.IsComObject(dataObject)) { 
                    return (IDataObject)dataObject;
                }
                else {
                    return new DataObject(dataObject); 
                }
            } 
            return null; 
        }
 
        // <-- WHIDBEY ADDITIONS

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        public static void Clear() { 
            Clipboard.SetDataObject(new DataObject());
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        public static bool ContainsAudio() { 
            IDataObject dataObject = Clipboard.GetDataObject(); 
            if (dataObject != null) {
                return dataObject.GetDataPresent(DataFormats.WaveAudio, false); 
            }

            return false;
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        public static bool ContainsData(string format) {
            IDataObject dataObject = Clipboard.GetDataObject();
            if (dataObject != null) {
                return dataObject.GetDataPresent(format, false); 
            }
 
            return false; 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        public static bool ContainsFileDropList() {
            IDataObject dataObject = Clipboard.GetDataObject(); 
            if (dataObject != null) { 
                return dataObject.GetDataPresent(DataFormats.FileDrop, true);
            } 

            return false;
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        public static bool ContainsImage() { 
            IDataObject dataObject = Clipboard.GetDataObject();
            if (dataObject != null) {
                return dataObject.GetDataPresent(DataFormats.Bitmap, true);
            } 

            return false; 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        public static bool ContainsText() { 
            if (Environment.OSVersion.Platform != System.PlatformID.Win32NT ||
                Environment.OSVersion.Version.Major < 5) 
            { 
                return ContainsText(TextDataFormat.Text);
            } 
            else {
                return ContainsText(TextDataFormat.UnicodeText);
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        public static bool ContainsText(TextDataFormat format) {
            // valid values are 0x0-0x4 inclusive
            if (!ClientUtils.IsEnumValid(format, (int)format, (int)TextDataFormat.Text, (int)TextDataFormat.CommaSeparatedValue)){
                throw new InvalidEnumArgumentException("format", (int)format, typeof(TextDataFormat)); 
            }
 
            IDataObject dataObject = Clipboard.GetDataObject(); 
            if (dataObject != null) {
                return dataObject.GetDataPresent(ConvertToDataFormats(format), false); 
            }

            return false;
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        public static Stream GetAudioStream() {
            IDataObject dataObject = Clipboard.GetDataObject();
            if (dataObject != null) {
                return dataObject.GetData(DataFormats.WaveAudio, false) as Stream; 
            }
 
            return null; 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        public static object GetData(string format) {
            IDataObject dataObject = Clipboard.GetDataObject(); 
            if (dataObject != null) { 
                return dataObject.GetData(format);
            } 

            return null;
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        public static StringCollection GetFileDropList() { 
            IDataObject dataObject = Clipboard.GetDataObject();
            StringCollection retVal = new StringCollection();

            if (dataObject != null) { 
                string[] strings = dataObject.GetData(DataFormats.FileDrop, true) as string[];
                if (strings != null) { 
                    retVal.AddRange(strings); 
                }
            } 

            return retVal;
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        public static Image GetImage() { 
            IDataObject dataObject = Clipboard.GetDataObject();
            if (dataObject != null) {
                return dataObject.GetData(DataFormats.Bitmap, true) as Image;
            } 

            return null; 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        public static string GetText() { 
            // Pass in Text format for Win98...
            if (Environment.OSVersion.Platform != System.PlatformID.Win32NT || 
                Environment.OSVersion.Version.Major < 5) 
            {
                return GetText(TextDataFormat.Text); 
            }
            else {
                return GetText(TextDataFormat.UnicodeText);
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        public static string GetText(TextDataFormat format) {
            // valid values are 0x0 to 0x4 inclusive
            if (!ClientUtils.IsEnumValid(format, (int)format, (int)TextDataFormat.Text, (int)TextDataFormat.CommaSeparatedValue)) 
            {
                throw new InvalidEnumArgumentException("format", (int)format, typeof(TextDataFormat)); 
            } 

            IDataObject dataObject = Clipboard.GetDataObject(); 
            if (dataObject != null) {
                string text = dataObject.GetData(ConvertToDataFormats(format), false) as string;
                if (text != null) {
                    return text; 
                }
            } 
 
            return String.Empty;
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        public static void SetAudio(byte[] audioBytes) { 
            if (audioBytes == null) { 
                throw new ArgumentNullException("audioBytes");
            } 
            SetAudio(new MemoryStream(audioBytes));
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        public static void SetAudio(Stream audioStream) {
            if (audioStream == null) { 
                throw new ArgumentNullException("audioStream");
            }
            IDataObject dataObject = new DataObject();
            dataObject.SetData(DataFormats.WaveAudio, false, audioStream); 
            Clipboard.SetDataObject(dataObject, true);
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        public static void SetData(string format, object data) {
            //Note: We delegate argument checking to IDataObject.SetData, if it wants to do so. 
            IDataObject dataObject = new DataObject();
            dataObject.SetData(format, data); 
            Clipboard.SetDataObject(dataObject, true); 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        public static void SetFileDropList(StringCollection filePaths) {
            if (filePaths == null) { 
                throw new ArgumentNullException("filePaths"); 
            }
            // VsWhidbey:432618 throw Argument exception for zero-length filepath collection. 
            if (filePaths.Count == 0)
            {
                throw new ArgumentException(SR.GetString(SR.CollectionEmptyException));
            } 

            //VSWhidbey #163538 - Validate the paths to make sure they don't contain invalid characters 
            foreach (string path in filePaths) { 
                try {
                    string temp = Path.GetFullPath(path); 
                }
                catch (Exception e) {
                    if (ClientUtils.IsSecurityOrCriticalException(e)) {
                        throw; 
                    }
 
                    throw new ArgumentException(SR.GetString(SR.Clipboard_InvalidPath, path, "filePaths"), e); 
                }
            } 

            if (filePaths.Count > 0) {
                IDataObject dataObject = new DataObject();
                string[] strings = new string[filePaths.Count]; 
                filePaths.CopyTo(strings, 0);
                dataObject.SetData(DataFormats.FileDrop, true, strings); 
                Clipboard.SetDataObject(dataObject, true); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        public static void SetImage(Image image) { 
            if (image == null) { 
                throw new ArgumentNullException("image");
            } 
            IDataObject dataObject = new DataObject();
            dataObject.SetData(DataFormats.Bitmap, true, image);
            Clipboard.SetDataObject(dataObject, true);
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        public static void SetText(string text) {
            // Pass in Text format for Win98...
            if (Environment.OSVersion.Platform != System.PlatformID.Win32NT ||
                Environment.OSVersion.Version.Major < 5) 
            {
                SetText(text, TextDataFormat.Text); 
            } 
            else {
               SetText(text, TextDataFormat.UnicodeText); 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        public static void SetText(string text, TextDataFormat format) {
            if (String.IsNullOrEmpty(text)) { 
                throw new ArgumentNullException("text");
            }

            //valid values are 0x0 to 0x4 
            if (!ClientUtils.IsEnumValid(format, (int)format, (int)TextDataFormat.Text, (int)TextDataFormat.CommaSeparatedValue))
            { 
                throw new InvalidEnumArgumentException("format", (int)format, typeof(TextDataFormat)); 
            }
 
            IDataObject dataObject = new DataObject();
            dataObject.SetData(ConvertToDataFormats(format), false, text);
            Clipboard.SetDataObject(dataObject, true);
        } 

        private static string ConvertToDataFormats(TextDataFormat format) { 
            switch (format) { 
            case TextDataFormat.Text:
                return DataFormats.Text; 

            case TextDataFormat.UnicodeText:
                return DataFormats.UnicodeText;
 
            case TextDataFormat.Rtf:
                return DataFormats.Rtf; 
 
            case TextDataFormat.Html:
                return DataFormats.Html; 

            case TextDataFormat.CommaSeparatedValue:
                return DataFormats.CommaSeparatedValue;
            } 

            return DataFormats.UnicodeText; 
        } 

        // END - WHIDBEY ADDITIONS --> 

        private static void ThrowIfFailed(int hr) {
            //
            if (hr != 0) { 
                ExternalException e = new ExternalException(SR.GetString(SR.ClipboardOperationFailed), hr);
                throw e; 
            } 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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