本文实现在Android下图片的合成
布局设计比较简单：
<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/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：
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：
