<Button

android:id="@+id/button_capture"

android:text=“照相”

android:layout_width=“wrap_content”

android:layout_height=“wrap_content”

android:layout_gravity=“center”

/>

java代码

---

想要对摄像头进行一系列操作，包括获取图片，就要先获取Camera类，。

public static Camera getCameraInstance(){ //安全获取camera类

Camera camera = null;

try {

camera = Camera.open();

}

catch (Exception e){

}

return camera;

}

创建预览类，用来预览摄像头捕获的内容，解释看注释。

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {

private SurfaceHolder mHolder;

private Camera mCamera;

public CameraPreview(Context context, Camera camera) {

super(conte

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xt);

mCamera = camera; //通过构造方法，将获取的camera类传进来，进行绑定

mHolder = getHolder(); //设置回调

mHolder.addCallback(this);

mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

public void surfaceCreated(SurfaceHolder holder) {

//创建预览界面的方法，无需主动调用

try {

mCamera.setPreviewDisplay(holder);

mCamera.startPreview();

} catch (IOException e) {

}

}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

//当预览界面发生改变时会自动调用的方法，

if (mHolder.getSurface() == null){

//预览界面不存在的情况

return;

}

// 界面发生改变时，停止预览，比如按下拍照的按钮

try {

mCamera.stopPreview();

} catch (Exception e){

}

//重新开始预览

try {

mCamera.setPreviewDisplay(mHolder);

mCamera.startPreview();

} catch (Exception e){

Log.d(“error”, "Error starting camera preview: " + e.getMessage());

}

}

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

}

}

main_activity.java 文件的内容，具体看注释。

public class MainActivity extends AppCompatActivity {

private Camera mCamera;

private CameraPreview mPreview;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mCamera = getCameraInstance(); //通过自己封装的方法，获取Camera类

// 创建自己创建的预览类

mPreview = new CameraPreview(this, mCamera);

FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);

preview.addView(mPreview);//将预览类加入显示界面

Button button=findViewById(R.id.button_capture);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) { //设置按钮监听，实现点击按钮之后，进行拍照

mCamera.autoFocus(new Camera.AutoFocusCallback() { //自动聚焦

@Override

public void onAutoFocus(boolean success, Camera camera) {

// 从Camera捕获图片

mCamera.takePicture(null, null, mPicture);

}

});

}

});

}

public static Camera getCameraInstance(){ //安全获取camera类

Camera camera = null;

try {

camera = Camera.open();

}

catch (Exception e){

}

return camera;

}

private Camera.PictureCallback mPicture = new Camera.PictureCallback() {

//添加拍照的回调对象mPicture，mCamera.takePicture的必要参数

//实现将拍照的图片存储到自己想要的目录

@Override

public void onPictureTaken(byte[] data, Camera camera) {

File pictureFile = new File("/sdcard/" + System.currentTimeMillis()+".jpg"); //文件对象，指明路径

if (pictureFile == null){

Log.d(“error”, “Error creating media file, check storage permissions”);

return;

}