Android-拍照

直接上代码：
1，布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    >
    <SurfaceView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:id="@+id/sv_main_surface"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="takePhoto"
        android:text="拍照"
        />
</LinearLayout>
2,activity
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.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
    private SurfaceView sv_main_surface;
    private Camera camera;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sv_main_surface = (SurfaceView) findViewById(R.id.sv_main_surface);
        sv_main_surface.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder surfaceHolder) {
                //打开照相机
                camera = Camera.open();
                //设置参数
                Camera.Parameters parameters=camera.getParameters();
                //设置图片的格式
                parameters.setPictureFormat(PixelFormat.JPEG);
                //设置图片的质量
                parameters.set("jpeg-quality",85);
                camera.setParameters(parameters);
                //将画面展示到SurfaceView
                try {
                    camera.setPreviewDisplay(sv_main_surface.getHolder());
                } catch (IOException e) {
                    e.printStackTrace();
                }
                //开启预览效果
                camera.startPreview();}
            @Override
            public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
            }
            @Override
            public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
                if(camera!=null){
                    camera.stopPreview();
                    camera.release();
                    camera=null;}}});}
           public void takePhoto(View view){
             camera.takePicture(null, null, new Camera.PictureCallback() {
             @Override
             public void onPictureTaken(byte[] bytes, Camera camera) {
                //图片压缩技术
                Bitmap bitmap=BitmapFactory.decodeByteArray(bytes,0,bytes.length);
                try {
                    FileOutputStream fos=new FileOutputStream("/mnt/sdcard/G150820_"+System.currentTimeMillis()+".png");
                    bitmap.compress(Bitmap.CompressFormat.PNG,85,fos);
                    camera.stopPreview();
                    camera.startPreview();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }}});}}
3,在配置文件中加几个权限
<!-- 打开照相机的权限 -->
<uses-permission android:name="android.permission.CAMERA" />
<!--创建文件的权限-->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<!--写内存卡的权限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

效果如下图所示：