Question

我试图在触摸点的ImageView上绘制圆圈，但它会在左上角绘制。

我的代码是

ImageView imageView;
    private static int RESULT_LOAD_IMAGE = 1;
    Bitmap bmp;
    float touchY;
    float touchX;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView = (ImageView) findViewById(R.id.imageView1);
        imageView.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    touchX = event.getX();
                    touchY = event.getY();
                    imageView.setImageBitmap(drawCircle());
                    break;

                default:
                    break;
                }


                return false;
            }
        });
    }

    private Bitmap drawCircle() {
        Bitmap bitmap = bmp.copy(Bitmap.Config.ARGB_4444, true);
        bitmap.setPixel(imageView.getWidth(), imageView.getHeight(), 0);
        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint();
        paint.setStyle(Paint.Style.STROKE);
        paint.setColor(Color.RED);
        canvas.drawCircle(touchX, touchY, 100, paint);
        return bitmap;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.getimage:
            pickImage();
            break;

        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }

    private void pickImage() {
        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        startActivityForResult(intent, RESULT_LOAD_IMAGE);

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && data != null){
            Uri uri = data.getData();
            String[] filePath = {MediaStore.Images.Media.DATA};
            Cursor cursor = getContentResolver().query(uri, filePath, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePath[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();
            bmp = BitmapFactory.decodeFile(picturePath);
            imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }

和xml是

<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

我没有弄错。我想在触摸点画圆圈。任何帮助将不胜感激。

Answer 1

如果要创建一个大小为ImageView的新位图，这段代码可以正常工作。

然而，“bmp”位图可能比ImageView大得多并且被缩放。这就是你得到扭曲结果的原因。

在触摸点上在ImageView上绘制圆圈

1 个答案: