Methods > Operations > BitmapViewDrawToHdc method

Remarks

Renders the bitmap view of the given waveform range inside a graphical Device Context (HDC).

Before calling this method it's mandatory performing a previous sound's analysis through a call to the AnalyzeSoundFromFile or AnalyzeSoundFromFileRaw methods and waiting its completion through the WaveAnalysisDone event.

Syntax

[Visual Basic]

Public Function BitmapViewDrawToHdc (

hDC as IntPtr,

nPosLeft as Int32,

nPosTop as Int32,

nWidth as Int32,

nHeight as Int32,

nWaveformStereoMode as enumWaveformStereoModes,

bUseHalfColorsForPeaks as Boolean,

bShowMaskedGraphicItems as Boolean,

nStartPos as Int32,

nEndPos as Int32

) as enumWanErrorCodes

[C#]

public enumWanErrorCodes BitmapViewDrawToHdc (

IntPtr hDC,

Int32 nPosLeft,

Int32 nPosTop,

Int32 nWidth,

Int32 nHeight,

enumWaveformStereoModes nWaveformStereoMode,

bool bUseHalfColorsForPeaks,

bool bShowMaskedGraphicItems,

Int32 nStartPos,

Int32 nEndPos

);

[C++]

public: enumWanErrorCodes BitmapViewDrawToHdc (

IntPtr hDC,

Int32 nPosLeft,

Int32 nPosTop,

Int32 nWidth,

Int32 nHeight,

enumWaveformStereoModes nWaveformStereoMode,

bool bUseHalfColorsForPeaks,

bool bShowMaskedGraphicItems,

Int32 nStartPos,

Int32 nEndPos

);

Parameter

Description

hDC

Handle to the output graphical Device Context

nPosLeft

Horizontal left position, expressed in pixels, of the destination rectangle where the bitmap will be rendered on the Device Context

nPosTop

Vertical top position, expressed in pixels, of the destination rectangle where the bitmap will be rendered on the Device Context

nWidth

Width, expressed in pixels, of the destination rectangle on the Device Context

nHeight

Height, expressed in pixels, of the destination rectangle on the Device Context

nWaveformStereoMode

Visualization mode used for displaying stereo sounds

Supported values are the following:

Mnemonic constant	Value	Meaning
STEREO_MODE_CHANNELS_BOTH	0	Right and left channels are displayed separately on two different panes as seen on the pictures A and B above.
STEREO_MODE_CHANNELS_LEFT	1	Only the left channel content is displayed on a single pane
STEREO_MODE_CHANNELS_RIGHT	2	Only the right channel content is displayed on a single pane
STEREO_MODE_CHANNELS_MIXED	3	Right and left channels contents are mixed together and displayed on a single pane

bUseHalfColorsForPeaks

Boolean value that determines if waveform peaks will have a half intensity color.

Supported values are the following:

Mnemonic constant	Meaning
false	Doesn't use half color for peaks
true (default)	Uses half color for peaks

bShowMaskedGraphicItems

Boolean flag that determines if eventual graphic items, enabled/disabled through the BitmapViewGraphicItemsMaskSet method, should be rendered over the waveform.

Supported values are the following:

Mnemonic constant	Meaning
false	Doesn't render graphic items
true	Renders graphic items. See the How to add graphic items to the Waveform analyzer tutorial for details about graphic items management on the waveform analyzer.

nStartPos

Number representing the sound's position, expressed in milliseconds, where the waveform visualization begins.

The value 0 represents the sound's beginning.

nEndPos

Number representing the sound's position, expressed in milliseconds, where the waveform visualization ends.

The value -1 represents the sound's end.

Return value

Value	Meaning

Negative value	An error occurred (see the LastError property for further error details)
enumWanErrorCodes.ERR_WAN_NOERROR (0)	The method call was successful