Bitmap Constructors
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Initializes a new instance of the Bitmap class.
Overloads
Bitmap(Image) |
Initializes a new instance of the Bitmap class from the specified existing image. |
Bitmap(Stream) |
Initializes a new instance of the Bitmap class from the specified data stream. |
Bitmap(String) |
Initializes a new instance of the Bitmap class from the specified file. |
Bitmap(Image, Size) |
Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size. |
Bitmap(Int32, Int32) |
Initializes a new instance of the Bitmap class with the specified size. |
Bitmap(Stream, Boolean) |
Initializes a new instance of the Bitmap class from the specified data stream. |
Bitmap(String, Boolean) |
Initializes a new instance of the Bitmap class from the specified file. |
Bitmap(Type, String) |
Initializes a new instance of the Bitmap class from a specified resource. |
Bitmap(Image, Int32, Int32) |
Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size. |
Bitmap(Int32, Int32, Graphics) |
Initializes a new instance of the Bitmap class with the specified size and with the resolution of the specified Graphics object. |
Bitmap(Int32, Int32, PixelFormat) |
Initializes a new instance of the Bitmap class with the specified size and format. |
Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr) |
Initializes a new instance of the Bitmap class with the specified size, pixel format, and pixel data. |
Bitmap(Image)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified existing image.
public:
Bitmap(System::Drawing::Image ^ original);
public Bitmap (System.Drawing.Image original);
new System.Drawing.Bitmap : System.Drawing.Image -> System.Drawing.Bitmap
Public Sub New (original As Image)
Parameters
Applies to
Bitmap(Stream)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified data stream.
public:
Bitmap(System::IO::Stream ^ stream);
public Bitmap (System.IO.Stream stream);
new System.Drawing.Bitmap : System.IO.Stream -> System.Drawing.Bitmap
Public Sub New (stream As Stream)
Parameters
- stream
- Stream
The data stream used to load the image.
Exceptions
stream
does not contain image data or is null
.
-or-
stream
contains a PNG image file with a single dimension greater than 65,535 pixels.
Examples
The following code example demonstrates how to load a bitmap from a stream.
This example is designed to be used with Windows Forms. Create a form that contains a PictureBox named PictureBox1
. Paste the code into the form and call the InitializeStreamBitmap
method from the form's constructor or Load event-handling method.
void InitializeStreamBitmap()
{
try
{
System::Net::WebRequest^ request = System::Net::WebRequest::Create( "http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif" );
System::Net::WebResponse^ response = request->GetResponse();
System::IO::Stream^ responseStream = response->GetResponseStream();
Bitmap^ bitmap2 = gcnew Bitmap( responseStream );
PictureBox1->Image = bitmap2;
}
catch ( System::Net::WebException^ )
{
MessageBox::Show( "There was an error opening the image file."
"Check the URL" );
}
}
private void InitializeStreamBitmap()
{
try
{
System.Net.WebRequest request =
System.Net.WebRequest.Create(
"http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif");
System.Net.WebResponse response = request.GetResponse();
System.IO.Stream responseStream =
response.GetResponseStream();
Bitmap bitmap2 = new Bitmap(responseStream);
PictureBox1.Image = bitmap2;
}
catch(System.Net.WebException)
{
MessageBox.Show("There was an error opening the image file."
+ "Check the URL");
}
}
Private Sub InitializeStreamBitmap()
Try
Dim request As System.Net.WebRequest = _
System.Net.WebRequest.Create( _
"http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif")
Dim response As System.Net.WebResponse = request.GetResponse()
Dim responseStream As System.IO.Stream = response.GetResponseStream()
Dim bitmap2 As New Bitmap(responseStream)
PictureBox1.Image = bitmap2
Catch ex As System.Net.WebException
MessageBox.Show("There was an error opening the image file. Check the URL")
End Try
End Sub
Remarks
You must keep the stream open for the lifetime of the Bitmap.
Due to a limitation of the GDI+ decoder, an System.ArgumentException is thrown if you construct a bitmap from a .png image file with a single dimension greater than 65,535 pixels.
See also
Applies to
Bitmap(String)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified file.
public:
Bitmap(System::String ^ filename);
public Bitmap (string filename);
new System.Drawing.Bitmap : string -> System.Drawing.Bitmap
Public Sub New (filename As String)
Parameters
- filename
- String
The bitmap file name and path.
Exceptions
The specified file is not found.
Remarks
The file name and path can be relative to the application or an absolute path. Use this constructor to open images with the following file formats: BMP, GIF, EXIF, JPG, PNG and TIFF. For more information about supported formats, see Types of Bitmaps. The file remains locked until the Bitmap is disposed.
See also
Applies to
Bitmap(Image, Size)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.
public:
Bitmap(System::Drawing::Image ^ original, System::Drawing::Size newSize);
public Bitmap (System.Drawing.Image original, System.Drawing.Size newSize);
new System.Drawing.Bitmap : System.Drawing.Image * System.Drawing.Size -> System.Drawing.Bitmap
Public Sub New (original As Image, newSize As Size)
Parameters
Exceptions
The operation failed.
Applies to
Bitmap(Int32, Int32)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class with the specified size.
public:
Bitmap(int width, int height);
public Bitmap (int width, int height);
new System.Drawing.Bitmap : int * int -> System.Drawing.Bitmap
Public Sub New (width As Integer, height As Integer)
Parameters
Exceptions
The operation failed.
Remarks
This constructor creates a Bitmap with a PixelFormat enumeration value of Format32bppArgb.
Applies to
Bitmap(Stream, Boolean)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified data stream.
public:
Bitmap(System::IO::Stream ^ stream, bool useIcm);
public Bitmap (System.IO.Stream stream, bool useIcm);
new System.Drawing.Bitmap : System.IO.Stream * bool -> System.Drawing.Bitmap
Public Sub New (stream As Stream, useIcm As Boolean)
Parameters
- stream
- Stream
The data stream used to load the image.
Exceptions
stream
does not contain image data or is null
.
-or-
stream
contains a PNG image file with a single dimension greater than 65,535 pixels.
Remarks
You must keep the stream open for the lifetime of the Bitmap.
Due to a limitation of the GDI+ decoder, an System.ArgumentException is thrown if you construct a bitmap from a .png image file with a single dimension greater than 65,535 pixels.
See also
Applies to
Bitmap(String, Boolean)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified file.
public:
Bitmap(System::String ^ filename, bool useIcm);
public Bitmap (string filename, bool useIcm);
new System.Drawing.Bitmap : string * bool -> System.Drawing.Bitmap
Public Sub New (filename As String, useIcm As Boolean)
Parameters
- filename
- String
The name of the bitmap file.
Examples
The following code example demonstrates how to construct a new bitmap from a file. The example uses the GetPixel and SetPixel methods to recolor the image. It also uses the PixelFormat property.
This example is designed to be used with a Windows Form that contains a Label, PictureBox and Button named Label1
, PictureBox1
and Button1
, respectively. Paste the code into the form and associate the Button1_Click
method with the button's Click event.
private:
Bitmap^ image1;
void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
try
{
// Retrieve the image.
image1 = gcnew Bitmap( "C:\\Documents and Settings\\All Users\\"
"Documents\\My Music\\music.bmp",true );
int x;
int y;
// Loop through the images pixels to reset color.
for ( x = 0; x < image1->Width; x++ )
{
for ( y = 0; y < image1->Height; y++ )
{
Color pixelColor = image1->GetPixel( x, y );
Color newColor = Color::FromArgb( pixelColor.R, 0, 0 );
image1->SetPixel( x, y, newColor );
}
}
// Set the PictureBox to display the image.
PictureBox1->Image = image1;
// Display the pixel format in Label1.
Label1->Text = String::Format( "Pixel format: {0}", image1->PixelFormat );
}
catch ( ArgumentException^ )
{
MessageBox::Show( "There was an error."
"Check the path to the image file." );
}
}
Bitmap image1;
private void Button1_Click(System.Object sender, System.EventArgs e)
{
try
{
// Retrieve the image.
image1 = new Bitmap(@"C:\Documents and Settings\All Users\"
+ @"Documents\My Music\music.bmp", true);
int x, y;
// Loop through the images pixels to reset color.
for(x=0; x<image1.Width; x++)
{
for(y=0; y<image1.Height; y++)
{
Color pixelColor = image1.GetPixel(x, y);
Color newColor = Color.FromArgb(pixelColor.R, 0, 0);
image1.SetPixel(x, y, newColor);
}
}
// Set the PictureBox to display the image.
PictureBox1.Image = image1;
// Display the pixel format in Label1.
Label1.Text = "Pixel format: "+image1.PixelFormat.ToString();
}
catch(ArgumentException)
{
MessageBox.Show("There was an error." +
"Check the path to the image file.");
}
}
Dim image1 As Bitmap
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
Try
' Retrieve the image.
image1 = New Bitmap( _
"C:\Documents and Settings\All Users\Documents\My Music\music.bmp", _
True)
Dim x, y As Integer
' Loop through the images pixels to reset color.
For x = 0 To image1.Width - 1
For y = 0 To image1.Height - 1
Dim pixelColor As Color = image1.GetPixel(x, y)
Dim newColor As Color = _
Color.FromArgb(pixelColor.R, 0, 0)
image1.SetPixel(x, y, newColor)
Next
Next
' Set the PictureBox to display the image.
PictureBox1.Image = image1
' Display the pixel format in Label1.
Label1.Text = "Pixel format: " + image1.PixelFormat.ToString()
Catch ex As ArgumentException
MessageBox.Show("There was an error." _
& "Check the path to the image file.")
End Try
End Sub
Remarks
Use this constructor to open images with the following file formats: BMP, GIF, EXIF, JPG, PNG and TIFF. For more information about supported formats, see Types of Bitmaps. The file remains locked until the Bitmap is disposed.
See also
Applies to
Bitmap(Type, String)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from a specified resource.
public:
Bitmap(Type ^ type, System::String ^ resource);
public Bitmap (Type type, string resource);
new System.Drawing.Bitmap : Type * string -> System.Drawing.Bitmap
Public Sub New (type As Type, resource As String)
Parameters
- type
- Type
The class used to extract the resource.
- resource
- String
The name of the resource.
Examples
The following code example demonstrates how to construct a bitmap from a type, and how to use the Save method. To run this example, paste the code into a Windows Form. Handle the form's Paint event and call the ConstructFromResourceSaveAsGif
method, passing e
as PaintEventArgs
private:
void ConstructFromResourceSaveAsGif(PaintEventArgs^ e)
{
// Construct a bitmap from the button image resource.
Bitmap^ bmp1 = gcnew Bitmap(Button::typeid, "Button.bmp");
String^ savePath =
Environment::GetEnvironmentVariable("TEMP") + "\\Button.bmp";
try
{
// Save the image as a GIF.
bmp1->Save(savePath, System::Drawing::Imaging::ImageFormat::Gif);
}
catch (IOException^)
{
// Carry on regardless
}
// Construct a new image from the GIF file.
Bitmap^ bmp2 = nullptr;
if (File::Exists(savePath))
{
bmp2 = gcnew Bitmap(savePath);
}
// Draw the two images.
e->Graphics->DrawImage(bmp1, Point(10, 10));
// If bmp1 did not save to disk, bmp2 may be null
if (bmp2 != nullptr)
{
e->Graphics->DrawImage(bmp2, Point(10, 40));
}
// Dispose of the image files.
delete bmp1;
if (bmp2 != nullptr)
{
delete bmp2;
}
}
private void ConstructFromResourceSaveAsGif(PaintEventArgs e)
{
// Construct a bitmap from the button image resource.
Bitmap bmp1 = new Bitmap(typeof(Button), "Button.bmp");
// Save the image as a GIF.
bmp1.Save("c:\\button.gif", System.Drawing.Imaging.ImageFormat.Gif);
// Construct a new image from the GIF file.
Bitmap bmp2 = new Bitmap("c:\\button.gif");
// Draw the two images.
e.Graphics.DrawImage(bmp1, new Point(10, 10));
e.Graphics.DrawImage(bmp2, new Point(10, 40));
// Dispose of the image files.
bmp1.Dispose();
bmp2.Dispose();
}
Private Sub ConstructFromResourceSaveAsGif(ByVal e As PaintEventArgs)
' Construct a bitmap from the button image resource.
Dim bmp1 As New Bitmap(GetType(Button), "Button.bmp")
' Save the image as a GIF.
bmp1.Save("c:\button.gif", System.Drawing.Imaging.ImageFormat.Gif)
' Construct a new image from the GIF file.
Dim bmp2 As New Bitmap("c:\button.gif")
' Draw the two images.
e.Graphics.DrawImage(bmp1, New Point(10, 10))
e.Graphics.DrawImage(bmp2, New Point(10, 40))
' Dispose of the image files.
bmp1.Dispose()
bmp2.Dispose()
End Sub
Remarks
This constructor combines the namespace of the given type with the string name of the resource and looks for a match in the assembly manifest. For example you can pass in the Button type and Button.bmp
to this constructor and it will look for a resource named System.Windows.Forms.Button.bmp
.
See also
Applies to
Bitmap(Image, Int32, Int32)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.
public:
Bitmap(System::Drawing::Image ^ original, int width, int height);
public Bitmap (System.Drawing.Image original, int width, int height);
new System.Drawing.Bitmap : System.Drawing.Image * int * int -> System.Drawing.Bitmap
Public Sub New (original As Image, width As Integer, height As Integer)
Parameters
Exceptions
The operation failed.
Applies to
Bitmap(Int32, Int32, Graphics)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
public:
Bitmap(int width, int height, System::Drawing::Graphics ^ g);
public Bitmap (int width, int height, System.Drawing.Graphics g);
new System.Drawing.Bitmap : int * int * System.Drawing.Graphics -> System.Drawing.Bitmap
Public Sub New (width As Integer, height As Integer, g As Graphics)
Parameters
Exceptions
g
is null
.
Remarks
The new Bitmap that this method creates takes its horizontal and vertical resolution from the DpiX and DpiY properties of g
, respectively.
Applies to
Bitmap(Int32, Int32, PixelFormat)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class with the specified size and format.
public:
Bitmap(int width, int height, System::Drawing::Imaging::PixelFormat format);
public Bitmap (int width, int height, System.Drawing.Imaging.PixelFormat format);
new System.Drawing.Bitmap : int * int * System.Drawing.Imaging.PixelFormat -> System.Drawing.Bitmap
Public Sub New (width As Integer, height As Integer, format As PixelFormat)
Parameters
- format
- PixelFormat
The pixel format for the new Bitmap. This must specify a value that begins with Format
.
Exceptions
A PixelFormat value is specified whose name does not start with Format. For example, specifying Gdi will cause an ArgumentException, but Format48bppRgb will not.
Applies to
Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr)
- Source:
- Bitmap.cs
- Source:
- Bitmap.cs
Initializes a new instance of the Bitmap class with the specified size, pixel format, and pixel data.
public:
Bitmap(int width, int height, int stride, System::Drawing::Imaging::PixelFormat format, IntPtr scan0);
public Bitmap (int width, int height, int stride, System.Drawing.Imaging.PixelFormat format, IntPtr scan0);
new System.Drawing.Bitmap : int * int * int * System.Drawing.Imaging.PixelFormat * nativeint -> System.Drawing.Bitmap
Public Sub New (width As Integer, height As Integer, stride As Integer, format As PixelFormat, scan0 As IntPtr)
Parameters
- stride
- Int32
Integer that specifies the byte offset between the beginning of one scan line and the next. This is usually (but not necessarily) the number of bytes in the pixel format (for example, 2 for 16 bits per pixel) multiplied by the width of the bitmap. The value passed to this parameter must be a multiple of four.
- format
- PixelFormat
The pixel format for the new Bitmap. This must specify a value that begins with Format
.
- scan0
-
IntPtr
nativeint
Pointer to an array of bytes that contains the pixel data.
Exceptions
A PixelFormat value is specified whose name does not start with Format. For example, specifying Gdi will cause an ArgumentException, but Format48bppRgb will not.
Examples
The following code example shows how to use the Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr) constructor. This example is designed to be used with Windows Forms and requires a PaintEventArgs parameter, which is a parameter of the Paint event.
private void BitmapConstructorEx(PaintEventArgs e)
{
// Create a bitmap.
Bitmap bmp = new Bitmap("c:\\fakePhoto.jpg");
// Retrieve the bitmap data from the bitmap.
System.Drawing.Imaging.BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),
ImageLockMode.ReadOnly, bmp.PixelFormat);
//Create a new bitmap.
Bitmap newBitmap = new Bitmap(200, 200, bmpData.Stride, bmp.PixelFormat, bmpData.Scan0);
bmp.UnlockBits(bmpData);
// Draw the new bitmap.
e.Graphics.DrawImage(newBitmap, 10, 10);
}
Private Sub BitmapConstructorEx(ByVal e As PaintEventArgs)
' Create a bitmap.
Dim bmp As New Bitmap("c:\fakePhoto.jpg")
' Retrieve the bitmap data from the bitmap.
Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(New Rectangle(0, 0, bmp.Width, bmp.Height), _
ImageLockMode.ReadOnly, bmp.PixelFormat)
'Create a new bitmap.
Dim newBitmap As New Bitmap(200, 200, bmpData.Stride, bmp.PixelFormat, bmpData.Scan0)
bmp.UnlockBits(bmpData)
' Draw the new bitmap.
e.Graphics.DrawImage(newBitmap, 10, 10)
End Sub
Remarks
The caller is responsible for allocating and freeing the block of memory specified by the scan0
parameter. However, the memory should not be released until the related Bitmap is released.