- 关键点
canvas.drawBitmap(bitmap, srcRect, dstRect, null);
将bitmap的srcRect区域绘制到canvas的dstRect区域
- Demo
main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rl_root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/background_dark"
android:orientation="horizontal" >
<ImageView
android:id="@+id/iv_bmp1"
android:layout_width="80dp"
android:layout_height="100dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="20dp"
android:layout_marginStart="20dp"
android:layout_marginTop="20dp"
android:contentDescription="@null"
android:src="@drawable/baby" />
<ImageView
android:id="@+id/iv_bmp2"
android:layout_width="80dp"
android:layout_height="100dp"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginEnd="20dp"
android:layout_marginRight="20dp"
android:layout_marginTop="20dp"
android:contentDescription="@null"
android:src="@drawable/baby2" />
<Button
android:id="@+id/btn_merge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/iv_bmp1"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="Merge" />
<ImageView
android:id="@+id/iv_bmp_merge"
android:layout_width="160dp"
android:layout_height="100dp"
android:layout_below="@id/btn_merge"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:contentDescription="@null" />
</RelativeLayout>
目的就是将ivBmp1和ivBmp2上的图片,合并之后,显示在iv_bmp_merger上
- MainActivity.java
package net.mobctrl.mergebitmap;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
/**
*
* @author Zheng Haibo
* @web http://www.mobctrl.net
*
*/
public class MainActivity extends Activity {
private ImageView ivBmp1;
private ImageView ivBmp2;
private ImageView ivBmpMerge;
private Button mergeBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initUi();
}
private void initUi() {
ivBmp1 = (ImageView) findViewById(R.id.iv_bmp1);
ivBmp2 = (ImageView) findViewById(R.id.iv_bmp2);
ivBmpMerge = (ImageView) findViewById(R.id.iv_bmp_merge);
mergeBtn = (Button) findViewById(R.id.btn_merge);
mergeBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showMergeBitmap();
}
});
}
private Handler handler = new Handler(new Callback() {
@Override
public boolean handleMessage(Message msg) {
Bitmap bitmap = (Bitmap) msg.obj;
ivBmpMerge.setImageBitmap(bitmap);
return false;
}
});
/**
* 显示合并的图
*/
protected void showMergeBitmap() {
new Thread(new Runnable() {
@Override
public void run() {
Bitmap bitmap = mergeBitmap();
Message messge = handler.obtainMessage();
messge.obj = bitmap;
handler.sendMessage(messge);
}
}).start();
}
/*
* 使用Canvas合并Bitmap
*/
private Bitmap mergeBitmap() {
// 获取ImageView上得Bitmap图片
Bitmap bmp1 = ((BitmapDrawable) ivBmp1.getDrawable()).getBitmap();
Bitmap bmp2 = ((BitmapDrawable) ivBmp2.getDrawable()).getBitmap();
// 创建空得背景bitmap
// 生成画布图像
Bitmap resultBitmap = Bitmap.createBitmap(ivBmpMerge.getWidth(),
ivBmpMerge.getHeight(), Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(resultBitmap);// 使用空白图片生成canvas
// 将bmp1绘制在画布上
Rect srcRect = new Rect(0, 0, bmp1.getWidth(), bmp1.getHeight());// 截取bmp1中的矩形区域
Rect dstRect = new Rect(0, 0, ivBmpMerge.getWidth() / 2,
ivBmpMerge.getHeight());// bmp1在目标画布中的位置
canvas.drawBitmap(bmp1, srcRect, dstRect, null);
// 将bmp2绘制在画布上
srcRect = new Rect(0, 0, bmp2.getWidth(), bmp2.getHeight());// 截取bmp1中的矩形区域
dstRect = new Rect(ivBmpMerge.getWidth() / 2, 0, ivBmpMerge.getWidth(),
ivBmpMerge.getHeight());// bmp2在目标画布中的位置
canvas.drawBitmap(bmp2, srcRect, dstRect, null);
// 将bmp1,bmp2合并显示
return resultBitmap;
}
}
- 运行效果
点击merge之后
时间: 2024-10-07 19:52:58