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Android读取/dev/graphics/fb0 屏幕截图

Android读取/dev/graphics/fb0 屏幕截图

作者: 一杯茶一本书 | 来源:发表于2016-01-27 11:35 被阅读1770次

    Android屏幕截图有很多方式这里只使用其中一种截图
    主要是读取/dev/graphics/fb0,进行转换,复杂点就在如何把读取的数据进行转换。
    可以参考一下这篇文章:http://blog.chinaaet.com/detail/28298
    下面给出程序代码

    /**
     * ScreenShotFb.java
     * 版权所有(C) 2014
     * 创建者:cuiran 2014-4-3 下午4:55:23
     */
    package com.ghyf.mplay.util;
    
    
    import java.io.DataInputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    
    import com.ghyf.mplay.value.ConstantValue;
    
    
    
    import android.app.Activity;
    import android.graphics.Bitmap;
    
    import android.graphics.PixelFormat;
    import android.util.DisplayMetrics;
    import android.view.Display;
    
    /**
     * FrameBuffer中获取Android屏幕截图 
     * @author cuiran
     * @version 1.0.0
     */
    public class ScreenShotFb {
    
        private static final String TAG="ScreenShotFb";
        
        final static String FB0FILE1 = "/dev/graphics/fb0";
    
        static File fbFile;
          //程序入口  
        public static  void shoot(){  
             try {  
                 /************ 创建锁对象 ************/
                    final Object lock = new Object();
                    
                    synchronized (lock) {
                        long start=System.currentTimeMillis();
                        Bitmap bitmap=getScreenShotBitmap();
                        long end=System.currentTimeMillis();
                        LogUtil.i(TAG, "getScreenShotBitmap time is :"+(end-start)+" ms");
                        String filePath= ConstantValue.ROOT_SDCARD_DIR+"/s.png";
    //                  String filePath= ConstantValue.ROOT_SDCARD_DIR+"/screens/"+System.currentTimeMillis()+".png";
                        ScreenShotFb.savePic(bitmap,filePath);  
                    }
             }catch (Exception e) {  
                LogUtil.e(TAG, "Exception error",e);
             }  
        
        
        }  
         //保存到sdcard  
        public static void savePic(Bitmap b,String strFileName){  
            FileOutputStream fos = null;  
            try {  
                fos = new FileOutputStream(strFileName);  
                if (null != fos)  
                {  
                    b.compress(Bitmap.CompressFormat.PNG, 50, fos);  
                    fos.flush();  
                    fos.close();  
                }  
            } catch (FileNotFoundException e) {  
                LogUtil.e(TAG, "FileNotFoundException error",e);
            } catch (IOException e) {  
                LogUtil.e(TAG, "IOException error",e);
            }  
            
            LogUtil.i(TAG, "savePic success");
        }  
        
         public static void init(Activity activity){  
            
                try {
                
                    DisplayMetrics dm = new DisplayMetrics();
                    Display display = activity.getWindowManager().getDefaultDisplay();
                    display.getMetrics(dm);
                    screenWidth = dm.widthPixels; // 屏幕宽(像素,如:480px)
                    screenHeight = dm.heightPixels; // 屏幕高(像素,如:800p)
                    int pixelformat = display.getPixelFormat();
                    PixelFormat localPixelFormat1 = new PixelFormat();
                    PixelFormat.getPixelFormatInfo(pixelformat, localPixelFormat1);
                    int deepth = localPixelFormat1.bytesPerPixel;// 位深
                    LogUtil.i(TAG, "deepth="+deepth);
                    piex = new byte[screenHeight * screenWidth*deepth] ;// 像素
                    colors = new int[screenHeight * screenWidth];
                    
                    
                    
                }catch(Exception e){
                    LogUtil.e(TAG, "Exception error",e);
                }
         }
         static DataInputStream dStream=null;
         static byte[] piex=null;
         static int[] colors =null;
         static int screenWidth;
         static int screenHeight;
         
        public static synchronized Bitmap getScreenShotBitmap() {
            FileInputStream buf = null;
            try {
                fbFile = new File(FB0FILE1);
                buf = new FileInputStream(fbFile);// 读取文件内容
                dStream=new DataInputStream(buf);
                dStream.readFully(piex);
                dStream.close();
                // 将rgb转为色值
                  for(int i=0;i<piex.length;i+=2)
                    {
                      colors[i/2]= (int)0xff000000 +
                                (int) (((piex[i+1]) << (16))&0x00f80000)+
                                (int) (((piex[i+1]) << 13)&0x0000e000)+
                                (int) (((piex[i]) << 5)&0x00001A00)+
                                (int) (((piex[i]) << 3)&0x000000f8);
                    }
    
               // 得到屏幕bitmap
                return Bitmap.createBitmap(colors, screenWidth, screenHeight,
                            Bitmap.Config.RGB_565);
                
            } catch (FileNotFoundException e) {
                LogUtil.e(TAG, "FileNotFoundException error",e);
            } catch (IOException e) {
                LogUtil.e(TAG, "IOException error",e);
            }catch (Exception e) {
                LogUtil.e(TAG, "Exception error",e);
            }  
            finally {
                if(buf!=null){
                    try {
                        buf.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            return null;
        }
      
    }
    
    

    调用时候需要先init 然后在shoot
    看到很多朋友咨询得到的数据花屏和数组越界
    这里跟设备的设备的位深和像素有关 需要修改这些代码。
    // 将rgb转为色值
    for(int i=0;i<piex.length;i+=2) {
    colors[i/2]= (int)0xff000000 +
    (int) (((piex[i+1]) << (16))&0x00f80000)+
    (int) (((piex[i+1]) << 13)&0x0000e000)+
    (int) (((piex[i]) << 5)&0x00001A00)+
    (int) (((piex[i]) << 3)&0x000000f8);
    }

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