多个摄像头在一个Activity里显示

首先：系统需要支持对多摄像头的显示

然后上代码：

第一步，是View代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context="com.csht.three.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <SurfaceView
            android:id="@+id/surfaceview1"
            android:layout_width="match_parent"
            android:layout_weight="1"
            android:layout_marginTop="5dp"
            android:layout_height="0dp"
            />
        <SurfaceView
            android:id="@+id/surfaceview2"
            android:layout_width="fill_parent"
            android:layout_weight="1"
            android:layout_marginTop="5dp"
            android:layout_height="0dp"
            />
        <SurfaceView
            android:id="@+id/surfaceview3"
            android:layout_width="fill_parent"
            android:layout_weight="1"
            android:layout_marginTop="5dp"
            android:layout_height="0dp"
            android:layout_marginBottom="5dp"
            />
    </LinearLayout>
</LinearLayout>

第二步：

private int cameraCount;
private void DoIt() {
    cameraCount = Camera.getNumberOfCameras();
    for (int i = 0; i<cameraCount; i++){
        getSurfaceholder(i);
    }
}
private SurfaceHolder getSurfaceholder(int i){
    SurfaceHolder surfaceHolder = null;
    if (i==0){
        surfaceHolder = surfaceview1.getHolder();
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        surfaceHolder.addCallback(new surfaceholderCallbackBack(i,getApplicationContext()));
    }
    if (i==1){
        surfaceHolder = surfaceview2.getHolder();
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        surfaceHolder.addCallback(new surfaceholderCallbackBack(i,getApplicationContext()));
    }
    if (i==2){
        surfaceHolder = surfaceview3.getHolder();
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        surfaceHolder.addCallback(new surfaceholderCallbackBack(i,getApplicationContext()));
    }
    return surfaceHolder;
}
第三步：
/**
 * Created by Administrator on 2017/7/17.
 */

public class surfaceholderCallbackBack implements SurfaceHolder.Callback {
    private Camera camera = null;
    private int cameraNum;
    private Context context;

    public surfaceholderCallbackBack(int cameraNum,Context context){
        this.cameraNum = cameraNum;
        this.context = context;
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // 获取camera对象
        //int cameraCount = Camera.getNumberOfCameras();
            camera = Camera.open(cameraNum);
           try {
                // 设置预览监听
                camera.setPreviewDisplay(holder);
                Camera.Parameters parameters = camera.getParameters();
                if (context.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
                    parameters.set("orientation", "portrait");
                    camera.setDisplayOrientation(90);
                    parameters.setRotation(90);
                } else {
                    parameters.set("orientation", "landscape");
                    camera.setDisplayOrientation(0);
                    parameters.setRotation(0);
                }
                camera.setParameters(parameters);
                // 启动摄像头预览
                camera.startPreview();
                System.out.println("camera.startpreview");

           } catch (IOException e) {
                e.printStackTrace();
                camera.release();
                System.out.println("camera.release");
            }
        
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        camera.autoFocus(new Camera.AutoFocusCallback() {
            @Override
            public void onAutoFocus(boolean success, Camera camera) {
                if (success) {
                    initCamera();// 实现相机的参数初始化
                    camera.cancelAutoFocus();// 只有加上了这一句，才会自动对焦。
                }
            }
        });

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {

    }

    // 相机参数的初始化设置
    private void initCamera() {
        Camera.Parameters parameters = camera.getParameters();
        parameters.setPictureFormat(PixelFormat.JPEG);
        parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);// 1连续对焦
        setDispaly(parameters, camera);
        camera.setParameters(parameters);
        camera.startPreview();
        camera.cancelAutoFocus();// 2如果要实现连续的自动对焦，这一句必须加上
    }

    // 控制图像的正确显示方向
    private void setDispaly(Camera.Parameters parameters, Camera camera) {
        if (Integer.parseInt(Build.VERSION.SDK) >= 8) {
            setDisplayOrientation(camera, 90);
        } else {
            parameters.setRotation(90);
        }

    }

    // 实现的图像的正确显示
    private void setDisplayOrientation(Camera camera, int i) {
        Method downPolymorphic;
        try {
            downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[]{int.class});
            if (downPolymorphic != null) {
                downPolymorphic.invoke(camera, new Object[]{i});
            }
        } catch (Exception e) {
            Log.e("Came_e", "图像出错");
        }
    }
}