Android 图片的合成

本文实现在Android下图片的合成

布局设计比较简单：

<RelativeLayout ="http://schemas.android.com/apk/res/android"  ="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/iv"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    /></RelativeLayout>

逻辑部分代码如下：

public class MainActivity extends Activity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    ImageView iv = (ImageView) findViewById(R.id.iv);    // 图片合成-画布 先去画A 再去画B    Bitmap bitmap = BitmapFactory.decodeResource(getResources(),        R.drawable.test); // bitmap为只读的    Bitmap alterBitmap = Bitmap.createBitmap(bitmap.getWidth(),        bitmap.getHeight(), bitmap.getConfig());    Canvas canvas = new Canvas(alterBitmap);    Paint paint = new Paint();    paint.setColor(Color.BLACK);    canvas.drawBitmap(bitmap, new Matrix(), paint);    Bitmap ic_luncher = BitmapFactory.decodeResource(getResources(),        R.drawable.ic_launcher);        canvas.drawBitmap(ic_luncher, new Matrix(), paint);    iv.setImageBitmap(alterBitmap);  }}

最后的效果如下：

Android 图片的合成 images/loading.gif' data-original="http://images2015.cnblogs.com/blog/617081/201609/617081-20160906190923285-1565964389.png" />

打开android手机的API Demo图标

选择Graphics，接着选择Xfermodes，如下：

这里显示了各种图片合成后的模式，我们可以在代码中实现，这里采用DARKEN模式，代码如下：

public class MainActivity extends Activity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    ImageView iv = (ImageView) findViewById(R.id.iv);    // 图片合成-画布 先去画A 再去画B    Bitmap bitmap = BitmapFactory.decodeResource(getResources(),        R.drawable.test); // bitmap为只读的    Bitmap alterBitmap = Bitmap.createBitmap(bitmap.getWidth(),        bitmap.getHeight(), bitmap.getConfig());    Canvas canvas = new Canvas(alterBitmap);    Paint paint = new Paint();    paint.setColor(Color.BLACK);     paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DARKEN));    canvas.drawBitmap(bitmap, new Matrix(), paint);    Bitmap ic_luncher = BitmapFactory.decodeResource(getResources(),        R.drawable.ic_launcher);    canvas.drawBitmap(ic_luncher, new Matrix(), paint);    iv.setImageBitmap(alterBitmap);  }}

效果如下：