Android 自定义相机的使用

概述

相机几乎是每个APP都要用到的功能，万一老板让你定制相机方不方？反正我是有点方。关于相机的两天奋斗总结免费送给你。

启动相机的两种方式

1.直接启动系统相机

  Intent intent = new Intent();  
  intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);  
  startActivity(intent);

或者指定返回图片的名称mCurrentPhotoFile

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(mCurrentPhotoFile));
        startActivityForResult(intent, CAMERA_WITH_DATA);

2.自定义启动相机 
今天以第二种为例。效果图如下

自定义相机的一般步骤

1. 创建显示相机画面的布局，Android已经为我们选定好SurfaceView
2. 通过SurfaceView#getHolder()获得链接Camera和SurfaceView的SurfaceHolder
3. Camame.open()打开相机
4. 通过SurfaceHolder链接Camera和SurfaceView

一般步骤的代码演示

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback, Camera.AutoFocusCallback {

    private static final String TAG = "CameraSurfaceView";

    private Context mContext;
    private SurfaceHolder holder;
    private Camera mCamera;

    private int mScreenWidth;
    private int mScreenHeight;

    public CameraSurfaceView(Context context) {
        this(context, null);
    }

    public CameraSurfaceView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CameraSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mContext = context;
        getScreenMetrix(context);
        initView();
    }

    private void getScreenMetrix(Context context) {
        WindowManager WM = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        WM.getDefaultDisplay().getMetrics(outMetrics);
        mScreenWidth = outMetrics.widthPixels;
        mScreenHeight = outMetrics.heightPixels;
    }

    private void initView() {
        holder = getHolder();//获得surfaceHolder引用
        holder.addCallback(this);
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置类型
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        Log.i(TAG, "surfaceCreated");
        if (mCamera == null) {
            mCamera = Camera.open();//开启相机
            try {
                mCamera.setPreviewDisplay(holder);//摄像头画面显示在Surface上
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        Log.i(TAG, "surfaceChanged");
        mCamera.startPreview();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        Log.i(TAG, "surfaceDestroyed");
        mCamera.stopPreview();//停止预览
        mCamera.release();//释放相机资源
        mCamera = null;
        holder = null;
    }

    @Override
    public void onAutoFocus(boolean success, Camera Camera) {
        if (success) {
            Log.i(TAG, "onAutoFocus success="+success);
        }
    }
}

添加相机和自动聚焦限权

<uses-permission