我已经在我的应用程序中通过使用SurfaceView的片段实现了这个功能。这个stackoverflow问题的链接和答案可以在这里找到

希望这对你有所帮助。

根据我的经验，如果你的应用程序设计为纵向和横向工作，你需要声明变量凸轮为静态。否则，onDestroy()在切换方向时被调用，它会破坏它，但不会释放Camera，因此不可能再次重新打开它。

package com.example.flashlight;

import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

public static Camera cam = null;// has to be static, otherwise onDestroy() destroys it

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

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

public void flashLightOn(View view) {

    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam = Camera.open();
            Parameters p = cam.getParameters();
            p.setFlashMode(Parameters.FLASH_MODE_TORCH);
            cam.setParameters(p);
            cam.startPreview();
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOn()",
                Toast.LENGTH_SHORT).show();
    }
}

public void flashLightOff(View view) {
    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam.stopPreview();
            cam.release();
            cam = null;
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOff",
                Toast.LENGTH_SHORT).show();
    }
}
}

为了证明我必须画这条线

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

从http://developer.android.com/reference/android/hardware/Camera.html

上面建议的台词对我不起作用。

在Marshmallow和上面的例子中，CameraManager的“setTorchMode()”似乎是答案。这对我来说很管用:

 final CameraManager mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
 CameraManager.TorchCallback torchCallback = new CameraManager.TorchCallback() {
     @Override
     public void onTorchModeUnavailable(String cameraId) {
         super.onTorchModeUnavailable(cameraId);
     }

     @Override
     public void onTorchModeChanged(String cameraId, boolean enabled) {
         super.onTorchModeChanged(cameraId, enabled);
         boolean currentTorchState = enabled;
         try {
             mCameraManager.setTorchMode(cameraId, !currentTorchState);
         } catch (CameraAccessException e){}



     }
 };

 mCameraManager.registerTorchCallback(torchCallback, null);//fires onTorchModeChanged upon register
 mCameraManager.unregisterTorchCallback(torchCallback);

试试这个。

CameraManager camManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    String cameraId = null; // Usually front camera is at 0 position.
    try {
        cameraId = camManager.getCameraIdList()[0];
        camManager.setTorchMode(cameraId, true);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }

我得到了自动闪光与以下简单的三步。

我刚刚在Manifest.xml文件中添加了相机和Flash权限

< uses-permission android: name = " android.permission。相机" / > < uses-feature android: name = " android.hardware。相机" / > < uses-permission android: name = " android.permission.FLASHLIGHT " / > < uses-feature android: name = " android.hardware.camera。Flash " android:required="false" />

In your Camera Code do this way. //Open Camera Camera mCamera = Camera.open(); //Get Camera Params for customisation Camera.Parameters parameters = mCamera.getParameters(); //Check Whether device supports AutoFlash, If you YES then set AutoFlash List<String> flashModes = parameters.getSupportedFlashModes(); if (flashModes.contains(android.hardware.Camera.Parameters.FLASH_MODE_AUTO)) { parameters.setFlashMode(Parameters.FLASH_MODE_AUTO); } mCamera.setParameters(parameters); mCamera.startPreview(); Build + Run —> Now Go to Dim light area and Snap photo, you should get auto flash light if device supports.

我已经在我的应用程序中通过使用SurfaceView的片段实现了这个功能。这个stackoverflow问题的链接和答案可以在这里找到

希望这对你有所帮助。