android简单的自定义涂鸦控件_图片涂鸦控件-优快云博客

这篇博客介绍了如何在Android中创建一个简单的自定义涂鸦控件，无需设置自定义属性。通过java代码调用setBitmap(Bitmap bitmap)方法即可使用。控件还提供了清除功能clear()以及可自定义画笔颜色和线宽的功能。用户可以进一步扩展以实现保存等操作。

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简单的自定义涂鸦控件，没有写自定义属性

java代码中找到view后直接setBitmap(Bitmap bitmap)后就可以使用了

提供清除方法clear（）

保存可以参考另一篇view转bitmap，不多写了

设置画笔颜色，线大小可自定义扩展

具体代码如下：

/**
 * Author txwang
 *
 * @version V1.0
 * Created by txwang on 2019/3/28.
 * Instruction :涂鸦控件
 * @date: 2019-03-28 15:30
 **/
public class ImageDoodleView extends View {

    private int width;
    private int hei;
    private Bitmap bitmap;
    private Paint paint;
    private Canvas canvas;
    private float xPosition = -1;
    private float yPosition = -1;
    private boolean isFirst = true;
    private Path doodlePath;

    public ImageDoodleView(Context context) {
        this(context,null);
    }

    public ImageDoodleView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        paint = new Paint();
        paint.setColor(Color.parseColor("#66ff0000"));
        paint.setStrokeWidth(10);
        paint.setAntiAlias(true);
        paint.setStrokeCap(Paint.Cap.ROUND);
        paint.setStrokeJoin(Paint.Join.ROUND);
        paint.setStyle(Paint.Style.STROKE);
        doodlePath = new Path();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        this.canvas = canvas;
        if (null != bitmap){
            Paint paint = new Paint();
//            int left = width / 2 - bitmap.getWidth()/2;
//            int right = width / 2 + bitmap.getWidth()/2;
//            int top = hei / 2 - bitmap.getHeight()/2;
//            int bottum = hei / 2 + bitmap.getHeight()/2;
            int left = 0;
            int right = width;
            int top = 0;
            int bottum = hei;
            Rect msgRect = new Rect(left,top,right,bottum);
            canvas.drawBitmap(bitmap,null,msgRect,paint);
            isFirst = false;
        }
        canvas.drawPath(doodlePath,paint);
    }

    public void clear() {
        isFirst = true;
        doodlePath.reset();
        invalidate();
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        xPosition = event.getX();
        yPosition = event.getY();
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:
                doodlePath.moveTo(xPosition,yPosition);
                break;
            case MotionEvent.ACTION_MOVE:
                doodlePath.lineTo(xPosition,yPosition);
                break;
        }
        invalidate();
        return true;
    }

    public void setBitmap(Bitmap bitmap){
        this.bitmap = bitmap;
        invalidate();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        this.width = w;
        this.hei = h;
    }
}