Android 照相机不工作

我正试图偷偷点击某人的照片。我得到的是正面摄像头和摄像头对象。但是，当我尝试单击takepicture时，我的应用程序崩溃了

package com.example.xx.xx;

import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {
    public final static String DEBUG_TAG = "MakePhotoActivity";
    private Camera camera;
    private int cameraId = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


    }

    public void onClick(View view) {

        // do we have a camera?
        if (!getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
            Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG)
                    .show();
        } else {
            cameraId = findFrontFacingCamera();
            if (cameraId < 0) {
                Toast.makeText(this, "No front facing camera found.",
                        Toast.LENGTH_LONG).show();
            } else {
                getCamera();
                camera.takePicture(null, null,
                        new PhotoHandler(this));
            }
        }
    }

    private void getCamera()
    {
        releaseCameraAndPreview();
        camera = Camera.open(cameraId);
        Log.d(DEBUG_TAG,"found the camera.");
        Log.d(DEBUG_TAG,"Camera is" + camera);

        camera.startPreview();
    }

    private int findFrontFacingCamera() {
        int cameraId = -1;
        // Search for the front facing camera
        int numberOfCameras = Camera.getNumberOfCameras();
        for (int i = 0; i < numberOfCameras; i++) {
            CameraInfo info = new CameraInfo();
            Camera.getCameraInfo(i, info);
            if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
                Log.d(DEBUG_TAG, "Camera found");
                cameraId = i;
                break;
            }
        }
        Log.d(DEBUG_TAG,"the camera id is" + cameraId);
        return cameraId;
    }
    private void releaseCameraAndPreview() {
        if (camera != null) {
            camera.release();
            camera = null;
        }
    }


    @Override
    protected void onPause() {
        if (camera != null) {
            camera.release();
            camera = null;
        }
        super.onPause();
    }
}

---

您的代码似乎很好。您是否在清单中添加了权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.CAMERA"/>

---

您的代码似乎很好。您是否在清单中添加了权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.CAMERA"/>

---

您需要定义摄影机处理程序回调方法

void onPictureTaken（字节[]数据，摄像头）

---

您需要定义摄影机处理程序回调方法

void onPictureTaken（字节[]数据，摄像头）

：将完全初始化的SurfaceHolder传递给setPreviewDisplay（SurfaceHolder）。如果没有曲面，相机将无法开始预览

只有在预览显示就绪后（在调用回调后），才能调用takePicture（）

：将完全初始化的SurfaceHolder传递给setPreviewDisplay（SurfaceHolder）。如果没有曲面，相机将无法开始预览

只有在预览显示就绪后（在调用回调后），才能调用takePicture（）