问题
In MainActivtiy, we use Glide to load URL image into imgSignature.
When imgSignature clicked, a custom dialog pop out and it will display the image in imgSign. Our problem is when we clicked the done button in the custom dialog, the image inside imgSignature become empty and getting this toast message bgDrawable null.
Why image in imgSignature will gone ?
lateinit var signDialog: Dialog
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
signDialog = Util().dialogSignature(getActivity())
var mSignature = signature(activity, null)
signDialog.relativeLayout2.addView(mSignature)
var image: Bitmap? = null
if (obj?.signature_image?.url != null) {
Glide.with(activity)
.load(obj?.signature_image?.url.toString())
.into(imgSignature)
}
imgSignature.setOnClickListener {
signDialog.show()
if (obj?.signature_image?.url != " ") {
Glide.with(activity)
.load(obj?.signature_image?.url.toString())
.into(signDialog.imgSign);
}
}
signDialog.doneTxt.setOnClickListener {
signDialog.dismiss()
imgSignature.setImageBitmap(getBitmapFromView(mSignature))
}
}
fun getBitmapFromView(view: View): Bitmap {
//Define a bitmap with the same size as the view
val returnedBitmap = Bitmap.createBitmap(250, 250, Bitmap.Config.ARGB_8888)
//Bind a canvas to it
val canvas = Canvas(returnedBitmap)
//Get the view's background
val bgDrawable = view.background
if (bgDrawable != null) {
longToast("bgDrawable not null")
//has background drawable, then draw it on the canvas
bgDrawable.draw(canvas)
}
else {
//does not have background drawable, then draw white background on the canvas
canvas.drawColor(Color.WHITE)
// draw the view on the canvas
view.draw(canvas)
longToast("bgDrawable null")
}
//return the bitmap
return returnedBitmap
}
}
Util
fun dialogSignature(context: Context?):Dialog{
var dialog = Dialog(context)
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
dialog.setContentView(R.layout.dialog_signature)
dialog.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT);
return dialog
}
dialog_signature
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/relativeLayout1"
android:layout_width="match_parent"
android:layout_height="230dp"
android:orientation="vertical"
android:background="@android:color/white">
<LinearLayout android:layout_width="0dp" android:layout_height="wrap_content"
android:background="@color/colorPrimaryShadow"
android:orientation="horizontal"
android:id="@+id/linearLayout1"
android:gravity="center"
android:layout_marginBottom="2dp" app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toTopOf="@+id/relativeLayout2" app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent">
<TextView
android:layout_marginLeft="10dp"
android:layout_weight="0.4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Place Signature"
android:textSize="17sp"
android:layout_gravity="right"/>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:id="@+id/doneTxt"
android:text="Done"
android:textColor="@color/colorDarkBlue"/>
</LinearLayout>
<RelativeLayout android:layout_width="0dp" android:layout_height="0dp"
android:id="@+id/relativeLayout2"
android:background="@color/colorWhite"
app:layout_constraintTop_toBottomOf="@+id/linearLayout1" app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="1.0">
<ImageView android:layout_width="match_parent" android:layout_height="match_parent"
android:id="@+id/imgSign"/>
</RelativeLayout>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_below="@+id/linearLayout1"
android:textColor="@color/colorDarkBlue"
android:text="Clear" app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp" app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp" app:layout_constraintHorizontal_bias="1.0"
android:layout_marginBottom="16dp" app:layout_constraintBottom_toBottomOf="parent"
android:id="@+id/clearTxt"/>
</android.support.constraint.ConstraintLayout>
Happy chinese new year to all chinese
Edit
I tried @rafa answer, but get this exception
cannot be cast to android.widget.ImageView
on line
val bgDrawable = (view as ImageView).drawable
signture
inner class signature(context: Context, attrs: AttributeSet?) : View(context, attrs) {
private val paint = Paint()
private val path = Path()
private var lastTouchX: Float = 0.toFloat()
private var lastTouchY: Float = 0.toFloat()
private val dirtyRect = RectF()
private val STROKE_WIDTH = 5f
private val HALF_STROKE_WIDTH = STROKE_WIDTH / 2
init {
paint.setAntiAlias(true)
paint.setColor(Color.BLACK)
paint.setStyle(Paint.Style.STROKE)
paint.setStrokeJoin(Paint.Join.ROUND)
paint.setStrokeWidth(STROKE_WIDTH)
}
override fun onDraw(canvas: Canvas) {
canvas.drawPath(path, paint)
}
override fun onTouchEvent(event: MotionEvent): Boolean {
val eventX = event.x
val eventY = event.y
// mGetSign.setEnabled(true)
when (event.action) {
MotionEvent.ACTION_DOWN -> {
path.moveTo(eventX, eventY)
lastTouchX = eventX
lastTouchY = eventY
return true
}
MotionEvent.ACTION_MOVE,
MotionEvent.ACTION_UP -> {
resetDirtyRect(eventX, eventY)
val historySize = event.historySize
for (i in 0 until historySize) {
val historicalX = event.getHistoricalX(i)
val historicalY = event.getHistoricalY(i)
expandDirtyRect(historicalX, historicalY)
path.lineTo(historicalX, historicalY)
}
path.lineTo(eventX, eventY)
}
else -> {
debug("Ignored touch event: $event")
return false
}
}
invalidate(
(dirtyRect.left - HALF_STROKE_WIDTH).toInt(),
(dirtyRect.top - HALF_STROKE_WIDTH).toInt(),
(dirtyRect.right + HALF_STROKE_WIDTH).toInt(),
(dirtyRect.bottom + HALF_STROKE_WIDTH).toInt()
)
lastTouchX = eventX
lastTouchY = eventY
return true
}
private fun debug(string: String) {
// Log.v("log_tag", string)
}
private fun expandDirtyRect(historicalX: Float, historicalY: Float) {
if (historicalX < dirtyRect.left) {
dirtyRect.left = historicalX
} else if (historicalX > dirtyRect.right) {
dirtyRect.right = historicalX
}
if (historicalY < dirtyRect.top) {
dirtyRect.top = historicalY
} else if (historicalY > dirtyRect.bottom) {
dirtyRect.bottom = historicalY
}
}
private fun resetDirtyRect(eventX: Float, eventY: Float) {
dirtyRect.left = Math.min(lastTouchX, eventX)
dirtyRect.right = Math.max(lastTouchX, eventX)
dirtyRect.top = Math.min(lastTouchY, eventY)
dirtyRect.bottom = Math.max(lastTouchY, eventY)
}
}
回答1:
First of all, your mSignature doesnot hold any Image, so returns null when you try to retrieve Image( or background) from it. Removing the mSignature with imgSignature should work. But still am not sure why you need signature class.
lateinit var signDialog: Dialog
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
signDialog = Util().dialogSignature(getActivity())
//var mSignature = signature(activity, null)
//signDialog.relativeLayout2.addView(mSignature)
var image: Bitmap? = null
if (obj?.signature_image?.url != null) {
Glide.with(activity)
.load(obj?.signature_image?.url.toString())
.into(imgSignature)
}
imgSignature.setOnClickListener {
signDialog.show()
if (obj?.signature_image?.url != " ") {
Glide.with(activity)
.load(obj?.signature_image?.url.toString())
.into(signDialog.imgSign);
}
}
signDialog.doneTxt.setOnClickListener {
signDialog.dismiss()
// code change goes here imgSignature
imgSignature.setImageBitmap(getBitmapFromView(imgSignature))
}
}
You are using view.background instead of view.drawable as Imageview is set with src attribute by glide. And you have to setBounds for the drawable. Please find the changes below.
fun getBitmapFromView(view: View): Bitmap {
//Define a bitmap with the same size as the view
val returnedBitmap = Bitmap.createBitmap(250, 250, Bitmap.Config.ARGB_8888)
//Bind a canvas to it
val canvas = Canvas(returnedBitmap)
//Get the Imageview's src drawable
val bgDrawable = (view as ImageView).drawable
if (bgDrawable != null) {
bgDrawable.setbounds(10,10,240,240); // setting bounds with padding of 10
longToast("bgDrawable not null")
//has background drawable, then draw it on the canvas
bgDrawable.draw(canvas)
}
else {
//does not have background drawable, then draw white background on the canvas
canvas.drawColor(Color.WHITE)
// draw the view on the canvas
view.draw(canvas)
longToast("bgDrawable null")
}
//return the bitmap
return returnedBitmap
}
}
Happy New Year :)
来源：https://stackoverflow.com/questions/54519952/image-in-imageview-disappear