多媒体_画画板---保存画完图片，并发送广播，让图库可以看到

//布局文件

<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"    tools:context="${relativePackage}.${activityClass}" >    <ImageView        android:id="@+id/iv"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/bg" />    <LinearLayout         android:layout_alignParentBottom="true"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="horizontal">              <Button             android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="red"            android:text="红色"/>                <Button             android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="green"            android:text="绿色"/>                <Button             android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="brush"            android:text="刷子"/>                 <Button             android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="save"            android:text="保存"/>                            </LinearLayout></RelativeLayout>

//MainActivity配置文件

package com.example.demo;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import android.app.Activity;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.Bitmap.CompressFormat;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Matrix;import android.graphics.Paint;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.view.Menu;import android.view.MenuItem;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;public class MainActivity extends Activity {private int startX;private int startY;private Paint paint;private Canvas canvas;private ImageView iv;private Bitmap bmSrc;private Bitmap bmCopy;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//画一条线测试bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.bg);bmCopy = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());//画笔paint = new Paint();//画板canvas = new Canvas(bmCopy);//作画  到此步bmCopy和bmSrc的图片才会一样canvas.drawBitmap(bmSrc, new Matrix(), paint);//画一条线//canvas.drawLine(10, 10, 100, 100, paint);iv = (ImageView) findViewById(R.id.iv);iv.setImageBitmap(bmCopy);iv.setOnTouchListener(new OnTouchListener() {//手指触摸屏幕，就会产生触摸事件@Overridepublic boolean onTouch(View v, MotionEvent event) {//判断触摸事件的类型switch (event.getAction()) {    //表示触摸事件类型//手指触摸   开始坐标case MotionEvent.ACTION_DOWN://触摸事件中会包含手指触摸的坐标startX = (int) event.getX();   startY = (int) event.getY();   break;//手指滑动   结束坐标case MotionEvent.ACTION_MOVE:int newX = (int) event.getX();   int newY = (int) event.getY();   //指定线的起点和终点canvas.drawLine(startX,startY , newX, newY, paint);iv.setImageBitmap(bmCopy);//把本次画线的重点设置为下一次画线的起点startX = newX;startY = newY;break;//手指离开case MotionEvent.ACTION_UP:break;}//true表示告诉系统，这个触摸事件由IV处理//false表示不处理该触摸事件，事件往上传递return true;}});}//改变颜色public void red(View v){paint.setColor(Color.RED);}public void green(View v){paint.setColor(Color.GREEN);}public void brush(View v){//改变线条粗细paint.setStrokeWidth(8);}public void save(View v){/** * arg0:图片格式 * arg1:压缩质量 0-100 * arg2:输出流，保存的位置 */File file = new File("mnt/sdcard/tt2.png");FileOutputStream fos;try {//把图片压缩到本地文件fos = new FileOutputStream(file);bmCopy.compress(CompressFormat.PNG, 100, fos);fos.close();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}//手动发送sd卡就绪广播Intent intent = new Intent();intent.setAction(Intent.ACTION_MEDIA_MOUNTED);intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));//无序广播sendBroadcast(intent);}}

//添加权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>