custom display photo

1. Customize the camera preview and take a photo

package com.android.myapplication;

import android.content.ContentValues;
import android.content.res.Configuration;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.widget.Toast;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

public class CameraActivity extends AppCompatActivity implements SurfaceHolder.Callback ,Camera.PictureCallback {

    //The size of SurfaceView in xml
    private static final int LARGEST_WIDTH = 200;
    private static final int LARGEST_HEIGHT = 200;

    private android.view.SurfaceView svCamera;
    private Camera camera;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate (savedInstanceState);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_camera);
        initView();
        initData ();
    }

    private void initData() {
        SurfaceHolder holder = svCamera.getHolder();
        holder.addCallback(this);
    }

    private void initView() {
        svCamera = (SurfaceView) findViewById(R.id.sv_camera);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        int numberOfCameras = Camera.getNumberOfCameras();
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        //Test the code to see how many cameras are available
        if(numberOfCameras>1){
            for(int i=0;i<numberOfCameras;i++){
                Camera.getCameraInfo(i,cameraInfo);
                if(cameraInfo.facing== Camera.CameraInfo.CAMERA_FACING_BACK){
                    Log.e("==","后置");
                }else if(cameraInfo.facing== Camera.CameraInfo.CAMERA_FACING_FRONT){
                    Log.e("==","前置");
                }else {
                    Log.e("==","其他");
                }
            }
        }
        try {
            //After the above query, it is found that the judgment before and after different devices is not accurate. For example, the id of the front camera of our device is 0 instead of 1.
            camera = Camera.open(0);
            //The default preview of the system is landscape mode, and the vertical screen preview needs a rotation angle
            Camera.Parameters parameters = camera.getParameters();
            if(getResources().getConfiguration().orientation!= Configuration.ORIENTATION_LANDSCAPE){//竖屏
                parameters.set("orientation","portrait");
                camera.setDisplayOrientation(90);
                parameters.setRotation(90);
            }else{//横屏
                parameters.set("orientation","landscape");
                camera.setDisplayOrientation(0);
                parameters.setRotation(0);
            }
            //add special effects
            List<String> supportedColorEffects = parameters.getSupportedColorEffects();
            for (String currentEffect :
                    supportedColorEffects) {//Query whether related effects are supported
                if (Camera.Parameters.EFFECT_MONO.equals(currentEffect)){
                    parameters.setColorEffect(currentEffect);
                    break;
                }
            }
            //Change the camera preview size
            //First query the list of all sizes supported by the device
            int bestWidth = 0;
            int bestHeight = 0;
            List<Camera.Size> supportedPictureSizes = parameters.getSupportedPictureSizes();
            if(supportedPictureSizes.size()>1){
                for (Camera.Size aSize :
                        supportedPictureSizes) {
                    //Whether the set size meets the size conditions supported by the device: the supported size is greater than 0 and less than or equal to our custom size, which is reasonable
                    if(aSize.width>bestWidth && aSize.width<=LARGEST_WIDTH
                            && aSize.height>bestHeight && aSize.height<=LARGEST_HEIGHT){
                        bestWidth=aSize.width;
                        bestHeight=aSize.height;
                        break;
                    }

                }
                if(bestWidth!=0 && bestHeight!=0){
                    parameters.setPreviewSize(bestWidth,bestHeight);
                }
            }

            camera.setParameters(parameters);
            camera.setPreviewDisplay(holder);
            camera.startPreview();
        } catch (IOException e) {
            e.printStackTrace ();
            camera.release();
        }

    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        camera.stopPreview();
        camera.release();
    }

    public void take_photo(View view) {
        if(camera!=null){
            camera.takePicture(null,null,this);
        }
    }

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        Uri imgFileUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new ContentValues());
        try {
            OutputStream imgFileOS = getContentResolver().openOutputStream(imgFileUri);
            imgFileOS.write(data);
            imgFileOS.flush();
            imgFileOS.close();
            Toast.makeText(this, "The picture has been saved!", Toast.LENGTH_SHORT).show();
            camera.startPreview();
        } catch (FileNotFoundException e) {
            e.printStackTrace ();
        } catch (IOException e) {
            e.printStackTrace ();
        }
    }
}

xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.android.myapplication.CameraActivity">
    <SurfaceView
        android:id="@+id/sv_camera"
        android:layout_width="200dp"
        android:layout_height="200dp" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/sv_camera"
        android:layout_marginStart="52dp"
        android:layout_marginTop="16dp"
        android:onClick="take_photo"
        android:text="Photo" />

</RelativeLayout>