画画板小案例

- 日理万妓 2022-01-07 21:23 224阅读 0赞

画画板小案例

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
        private Paint paint;
        private Bitmap bitmapC;
    
        @SuppressLint("ClickableViewAccessibility")
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Button changC = findViewById(R.id.changeColor);
            changC.setOnClickListener(this);
            Button bold = findViewById(R.id.bold);
            bold.setOnClickListener(this);
            Button save = findViewById(R.id.save);
            save.setOnClickListener(this);
            final ImageView iv = findViewById(R.id.iv);
            Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.bg);
            bitmapC = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
            paint = new Paint();
            final Canvas canvas = new Canvas(bitmapC);
            canvas.drawBitmap(bitmap, new Matrix(), paint);
            iv.setImageBitmap(bitmapC);
            iv.setOnTouchListener(new View.OnTouchListener() {
                float startX = 0;
                float startY = 0;
    
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    int action = event.getAction();
                    switch (action) {
                        case MotionEvent.ACTION_DOWN:
                            startX = event.getX();
                            startY = event.getY();
                            break;
                        case MotionEvent.ACTION_UP:
                            break;
                        case MotionEvent.ACTION_MOVE:
                            float stopX = event.getX();
                            float stopY = event.getY();
                            canvas.drawLine(startX, startY, stopX, stopY, paint);
                            iv.setImageBitmap(bitmapC);
                            startX = stopX;
                            startY = stopY;
                            break;
                    }
                    return true;
                }
            });
        }
    
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.changeColor:
                    paint.setColor(Color.RED);
                    break;
                case R.id.bold:
                    paint.setStrokeWidth(20f);
                    break;
                case R.id.save:
                    try {
                        File file = new File(getFilesDir().getParent(), "dazuo.png");
                        FileOutputStream fos = new FileOutputStream(file);
                        boolean compress = bitmapC.compress(Bitmap.CompressFormat.PNG, 100, fos);
                        if (compress) {
                            Toast.makeText(this, "保存成功", Toast.LENGTH_SHORT).show();
                        }
                    } catch (FileNotFoundException e) {
                        Toast.makeText(this, "保存失败", Toast.LENGTH_SHORT).show();
                        e.printStackTrace();
                    }
                    break;
            }
        }
    }

代码已上传https://gitee.com/nangongyibin/Android\_DrawingVersion

转载于:https://www.cnblogs.com/nangongyibin/p/10252645.html