先给大家看下效果图 
我们用到一个SurfaceView来展示。具体我都写了注释。
package com.example.alarm_ontification;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.PixelFormat;import android.hardware.Camera;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import java.io.FileOutputStream;import java.io.IOException;public class MainActivity extends AppCompatActivity { PRivate SurfaceView sv_main_surfaceview; private Camera camera; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); sv_main_surfaceview = (SurfaceView) findViewById(R.id.sv_main_surfaceview); sv_main_surfaceview.getHolder().addCallback(new SurfaceHolder.Callback() { @Override public void surfaceCreated(SurfaceHolder surfaceHolder) { camera = Camera.open();//开启照相机 Camera.Parameters parameters= camera.getParameters();// 给摄像头设置参数 parameters.setPictureFormat(PixelFormat.JPEG);// 设置照片的输出格式 parameters.set("jpeg-quality", 85);// 设置照片的质量 camera.setParameters(parameters);// 给照相机设置参数 try { camera.setPreviewDisplay(sv_main_surfaceview.getHolder());//将摄像头的画面显示到SurfaceView控件上 camera.startPreview();//开启预览 } catch (IOException e) { e.printStackTrace(); } } @Override public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) { } @Override public void surfaceDestroyed(SurfaceHolder surfaceHolder) { } }); } public void opengo(View view){ //拍照 camera.takePicture(null, null, new Camera.PictureCallback() { @Override public void onPictureTaken(byte[] bytes, Camera camera) { Bitmap bitmap= BitmapFactory.decodeByteArray(bytes,0,bytes.length); try { FileOutputStream fos=new FileOutputStream("/mnt/sdcard/DCIM/camera/170223__"+System.currentTimeMillis()+".png"); bitmap.compress(Bitmap.CompressFormat.PNG,85,fos); camera.stopPreview(); camera.startPreview(); } catch (Exception e) { e.printStackTrace(); } } }); }}需要加入权限
<uses-permission android:name="android.permission.CAMERA"></uses-permission> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>新闻热点
疑难解答
