Question

我正在开发Android项目，我正在使用View类在画布上绘制空白圆圈。这是我的代码：

    Paint paint=new Paint();
    paint.setAntiAlias(true); // enable anti aliasing
    paint.setColor(Color.BLUE); // set default color to light green
    paint.setDither(true); // enable dithering
    paint.setStyle(Paint.Style.STROKE); // set to STOKE
    paint.setStrokeWidth(1);
    paint.setStrokeJoin(Paint.Join.ROUND); // set the join to round you want
    paint.setStrokeCap(Paint.Cap.ROUND);  // set the paint cap to round too
    canvas.drawCircle(x, y, 50, paint);

但是结果圈有一些锯齿，我怎么能画出没有任何锯齿的圆圈？

Answer 1

我已尝试使用以下显示的代码在画布中绘制圆圈：

public class MainActivity extends ActionBarActivity {
    ImageView image;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        image = (ImageView) findViewById(R.id.imv_Image);
        createBitMap();
    }

    private void createBitMap() {
        Bitmap bitMap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888); // creates
                                                                                // bmp
        bitMap = bitMap.copy(bitMap.getConfig(), true); // lets bmp to be
                                                        // mutable
        Canvas canvas = new Canvas(bitMap); // draw a canvas in defined bmp

        Paint paint = new Paint();
        // smooths
        paint.setAntiAlias(true);
        paint.setColor(Color.RED);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(4.5f);
        // opacity
        // p.setAlpha(0x80); //
        canvas.drawCircle(50, 50, 30, paint);
        image.setImageBitmap(bitMap);
    }
}

Answer 2

尝试设置Paint抗锯齿标志：

paint.setFlags(Paint.ANTI_ALIAS_FLAG)

请参阅：http://developer.android.com/reference/android/graphics/Paint.html#ANTI_ALIAS_FLAG

如果这不起作用，圆圈可能是抗锯齿的，但屏幕密度太低而无法注意。

在Android中绘制圆圈而不会出现锯齿

2 个答案: