Question

Android Paint with Image仅删除颜色而不是背景图像

我有一个相对布局，图像设置为MotionEvent.ACTION_MOVE:

然后有一个线性布局，我们可以用各种颜色绘制用橡皮擦我们可以清除颜色，这很好用

使用

立即删除带有

public void setErase(boolean isErase){
        //set erase true or false
        if(isErase){
            drawPaint.setAlpha(0xFF);
            drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));


        }
        else {
            drawPaint.setXfermode(null);
        }
}

颜色的

这个功能

case MotionEvent.ACTION_UP:
                drawCanvas.drawPath(drawPath, drawPaint);
                drawPath.reset();
                break;

问题是Bakground图像是如何被它擦掉的，

带

MotionEvent.ACTION_MOVE

图像被重置，我们在RelativeLayout

中找回图像

我想仅使用public class CustomView extends View { //drawing path private Path drawPath; //drawing and canvas paint private Paint drawPaint, canvasPaint; //initial color private int paintColor = 0xFF660000; //canvas private Canvas drawCanvas; //canvas bitmap private Bitmap canvasBitmap; private float brushSize, lastBrushSize; private int width, height; //comment to attached on the image private String comment; public CustomView(Context context, AttributeSet attrs ){ super(context, attrs); setupDrawing(); } private void setupDrawing(){ //get drawing area setup for interaction drawPath = new Path(); drawPaint = new Paint(); brushSize = getResources().getInteger(R.integer.medium_size); lastBrushSize = brushSize; //initialize drawPaint drawPaint.setColor(paintColor); //initialize drawPath drawPaint.setAntiAlias(true); drawPaint.setStrokeWidth(brushSize); drawPaint.setStyle(Paint.Style.STROKE); drawPaint.setStrokeJoin(Paint.Join.ROUND); drawPaint.setStrokeCap(Paint.Cap.ROUND); canvasPaint = new Paint(Paint.DITHER_FLAG); //drawCanvas.drawText("test", 20, 20, null); } public void setImageBitmap(Bitmap bmp){ Paint paint = new Paint(); paint.setAntiAlias(true); paint.setFilterBitmap(true); paint.setDither(true); /* * */ int bmp_width = bmp.getWidth(); int bmp_height = bmp.getHeight(); float scaleWidth = ((float) width) / bmp_width; float scaleHeight = ((float) height) / bmp_height; // CREATE A MATRIX FOR THE MANIPULATION Matrix matrix = new Matrix(); // RESIZE THE BIT MAP matrix.postScale(scaleWidth, scaleHeight); // "RECREATE" THE NEW BITMAP Bitmap resizedBitmap = Bitmap.createBitmap( bmp, 0, 0, bmp_width, bmp_height, matrix, false); // drawCanvas.drawBitmap(resizedBitmap, 0, 0, paint); invalidate(); } public void startNew(){ drawCanvas.drawColor(0, PorterDuff.Mode.CLEAR); invalidate(); } public void setComment(String commentText){ this.comment = commentText; } public void setErase(boolean isErase){ //set erase true or false if(isErase){ drawPaint.setAlpha(0xFF); drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR)); } else { drawPaint.setXfermode(null); } } public void setBrushSize(float newSize){ //update size brushSize= TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, newSize, getResources().getDisplayMetrics()); drawPaint.setStrokeWidth(brushSize); } public void setLastBrushSize(float lastSize){ lastBrushSize=lastSize; } public float getLastBrushSize(){ return lastBrushSize; } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); width = w; height = h; canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); drawCanvas = new Canvas(canvasBitmap); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint); canvas.drawPath(drawPath, drawPaint); } @Override public boolean onTouchEvent(MotionEvent event) { float touchX = event.getX(); float touchY = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { if(!Objects.equals(comment, "") && comment != null ){ canvasPaint.setTextSize(60); canvasPaint.setColor(paintColor); drawCanvas.drawText(comment, touchX, touchY, canvasPaint); comment = ""; return true; } else { drawPath.moveTo(touchX, touchY); } } break; case MotionEvent.ACTION_MOVE: drawPath.lineTo(touchX, touchY); break; case MotionEvent.ACTION_UP: drawCanvas.drawPath(drawPath, drawPaint); drawPath.reset(); break; default: return false; } invalidate(); return true; } public void setColor(String newColor){ //set color invalidate(); paintColor = Color.parseColor(newColor); drawPaint.setColor(paintColor); } public void setColor(int newColor){ invalidate(); drawPaint.setColor(newColor); } }

删除不是图像的颜色

我已提到这个https://github.com/fachrur/Gmbr

，代码是

自定义视图

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@mipmap/ic_launcher"

    >



<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation = "vertical"
    android:background="#00000000"
    tools:context=".MainActivity"
    android:id="@+id/main_activity">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:orientation="horizontal" >
        <ImageButton
            android:id="@+id/new_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/start_new"
            android:src="@drawable/new_pic"/>
        <ImageButton
            android:id="@+id/draw_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/start_new"
            android:src="@drawable/ic_brush"/>
        <ImageButton
            android:id="@+id/erase_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/start_new"
            android:src="@drawable/ic_eraser"/>
        <ImageButton
            android:id="@+id/save_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/start_new"
            android:src="@drawable/ic_save"/>
        <ImageButton
            android:id="@+id/takingPhoto_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/photo"
            android:src="@drawable/ic_camera"/>
        <ImageButton
            android:id="@+id/text_btn"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:contentDescription="@string/text"
            android:src="@drawable/ic_text"/>

    </LinearLayout>

    <com.rfachrur.gmbr.CustomView
        android:id="@+id/drawing"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_marginBottom="0dp"
        android:layout_marginLeft="0dp"
        android:layout_marginRight="0dp"
        android:layout_marginTop="0dp"
        android:layout_weight="1"
        android:background="#00000000"
        android:layout_margin="0dp" />


    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/select_img"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:text="@string/add_image"
            android:src="@drawable/ic_text"/>

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:orientation="vertical" >

            <!-- Top Row -->
            <LinearLayout
                android:id="@+id/paint_colors"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >
                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF660000"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF660000" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FFFF0000"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FFFF0000" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FFFF6600"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FFFF6600" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FFFFCC00"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FFFFCC00" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF009900"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF009900" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF009999"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF009999" />
            </LinearLayout>
            <!-- Bottom Row -->
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >
                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF0000FF"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF0000FF" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF990099"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF990099" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FFFF6666"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FFFF6666" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FFFFFFFF"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FFFFFFFF" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF787878"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF787878" />

                <ImageButton
                    android:layout_width="@dimen/large_brush"
                    android:layout_height="@dimen/large_brush"
                    android:layout_margin="2dp"
                    android:background="#FF000000"
                    android:contentDescription="@string/paint"
                    android:onClick="paintClicked"
                    android:src="@drawable/paint"
                    android:tag="#FF000000" />
            </LinearLayout>
        </LinearLayout>

    </LinearLayout>
</LinearLayout>

</RelativeLayout>

，布局

{{1}}

我只想删除不是背景图像的颜色

Answer 1

这实际上解决了我的问题，非常容易使用和实现

https://github.com/mukeshsolanki/DrawingView-Android

Android Paint with Image仅删除颜色而不是背景图像

1 个答案: