从图库中选择图像作为画布背景[Android]
我已经成功地实现了保存到画廊后,我在画布上完成绘图,但现在我需要打开一个图像从厨房,例如我的旧画,并使用它作为背景,经过一些搜索没有答案,可以帮助我。我已经开始尝试这样做了,但是任何关于如何实现这一目标的建议或解决方案都将是非常棒的 这是我的画布自定义视图: 读写权限已在另一个类中授予和处理从图库中选择图像作为画布背景[Android],android,kotlin,canvas,bitmap,save,Android,Kotlin,Canvas,Bitmap,Save,我已经成功地实现了保存到画廊后,我在画布上完成绘图,但现在我需要打开一个图像从厨房,例如我的旧画,并使用它作为背景,经过一些搜索没有答案,可以帮助我。我已经开始尝试这样做了,但是任何关于如何实现这一目标的建议或解决方案都将是非常棒的 这是我的画布自定义视图: 读写权限已在另一个类中授予和处理 var drawingColor: Int = ResourcesCompat.getColor(resources, R.color.colorBlack, null) var strok
var drawingColor: Int = ResourcesCompat.getColor(resources, R.color.colorBlack, null)
var strokeDrawWidth: Float = 12f
private var path = Path()
private val paths = ArrayList<Triple<Path, Int, Float>>()
private val undonePaths = ArrayList<Triple<Path, Int, Float>>()
private val extraCanvas: Canvas? = null
private var bitmapBackground: Bitmap? = null
private var motionTouchEventX = 0f
private var motionTouchEventY = 0f
private var currentX = 0f
private var currentY = 0f
private val touchTolerance = ViewConfiguration.get(context).scaledTouchSlop
private val paint = Paint().apply {
color = drawingColor
isAntiAlias = true
isDither = true
style = Paint.Style.STROKE
strokeJoin = Paint.Join.ROUND
strokeCap = Paint.Cap.ROUND
strokeWidth = strokeDrawWidth
}
fun loadCanvasBackground(bitmap: Bitmap) {
bitmapBackground = bitmap
invalidate()
}
fun saveCanvasDrawing() {
canvasCustomView.isDrawingCacheEnabled = true
val extraBitmap: Bitmap = canvasCustomView.drawingCache
MediaStore.Images.Media.insertImage(context.contentResolver, extraBitmap, "drawing", "Paint R")
}
fun resetCanvasDrawing() {
path.reset()
paths.clear()
invalidate()
}
fun undoCanvasDrawing() {
if (paths.size > 0) {
undonePaths.add(paths.removeAt(paths.size - 1))
invalidate()
} else {
Log.d("UNDO_ERROR", "Something went wrong with UNDO action")
}
}
fun redoCanvasDrawing() {
if (undonePaths.size > 0) {
paths.add(undonePaths.removeAt(undonePaths.size - 1))
invalidate()
} else {
Log.d("REDO_ERROR", "Something went wrong with REDO action")
}
}
override fun onDraw(canvas: Canvas?) {
super.onDraw(canvas)
if (bitmapBackground != null) {
extraCanvas?.drawBitmap(bitmapBackground!!, 0f, 0f, paint)
}
for (p in paths) {
paint.strokeWidth = p.third
paint.color = p.second
canvas?.drawPath(p.first, paint)
}
paint.color = drawingColor
paint.strokeWidth = strokeDrawWidth
canvas?.drawPath(path, paint)
}
override fun onTouchEvent(event: MotionEvent?): Boolean {
if (event == null)
return false
motionTouchEventX = event.x
motionTouchEventY = event.y
when (event.action) {
MotionEvent.ACTION_DOWN -> {
undonePaths.clear()
path.reset()
path.moveTo(motionTouchEventX, motionTouchEventY)
currentX = motionTouchEventX
currentY = motionTouchEventY
invalidate()
}
MotionEvent.ACTION_MOVE -> {
val distanceX = abs(motionTouchEventX - currentX)
val distanceY = abs(motionTouchEventY - currentY)
if (distanceX >= touchTolerance || distanceY >= touchTolerance) {
path.quadTo(
currentX,
currentY,
(motionTouchEventX + currentX) / 2,
(currentY + motionTouchEventY) / 2
)
currentX = motionTouchEventX
currentY = motionTouchEventY
}
invalidate()
}
MotionEvent.ACTION_UP -> {
path.lineTo(currentX, currentY)
extraCanvas?.drawPath(path, paint)
paths.add(Triple(path, drawingColor, strokeDrawWidth))
path = Path()
}
}
return true
}
override fun isSaveEnabled(): Boolean {
return true
}
所以,没有人回答,经过一些搜索和实验,我得到了一个有效的解决方案,使用它或适应您的需要,如果您将得到相同的情况 答案基于我问题中的代码-因此,如果您遗漏了一些依赖项,请检查它 Init companion对象,带有活动中库操作的请求代码 创建一个方法,从需要接收Uri的库中拾取图像 然后需要重写onActivityResult方法来接收Uri并将其发送到自定义视图 现在,在自定义视图中的onDraw方法中,您需要使用.drawBitmap将收到的Uri(也称位图)设置为画布的背景
companion object {
private const val GALLERY_REQUEST_CODE = 102
}
private fun pickFromGallery() {
val intent = Intent(Intent.ACTION_PICK)
intent.type = "image/*"
val imageTypes = arrayOf("image/jpeg", "image/png")
intent.putExtra(Intent.EXTRA_MIME_TYPES, imageTypes)
startActivityForResult(intent, GALLERY_REQUEST_CODE)
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if (requestCode == GALLERY_REQUEST_CODE) {
if (resultCode == Activity.RESULT_OK) {
val uri: Uri? = data?.data
if (uri != null) {
val bitmap = MediaStore.Images.Media.getBitmap(this.contentResolver, uri)
canvasCustomView.loadCanvasBackground(bitmap)
}
}
}
}
override fun onDraw(canvas: Canvas?) {
if (bitmapBackground != null) {
canvas?.drawBitmap(bitmapBackground!!, 0f, 0f, paint)
}