PaintCanvasActivity.java

package com.wuxiaolong.androidsamples.paintcanvas;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.wuxiaolong.androidsamples.R;

public class PaintCanvasActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_paint_canvas);
    }
    private void colorFilterTest() {
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.logo);
        Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(outBitmap);
//        RectF rectF = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
//        canvas.drawRoundRect(rectF, 80, 80, paint);
        canvas.drawBitmap(outBitmap, 0, 0, paint);
    }

    private void initRoundRectImage() {
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.dog);
        Bitmap outBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(outBitmap);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        RectF rectF = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
        canvas.drawRoundRect(rectF, 80, 80, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, 0, 0, paint);

    }
}