使用照相机开启闪光灯

package com.home.light;

import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import com.home.cameralight.R;

public class TestActivity extends Activity implements OnClickListener {
	Camera camera;
	Parameters params;
	private Button onBtn;
	private Button offBtn;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		camera = Camera.open();
		params = camera.getParameters();
		findView();
	}

	private void findView() {
		onBtn = (Button) findViewById(R.id.main_btn_on);
		onBtn.setOnClickListener(this);
		offBtn = (Button) findViewById(R.id.main_btn_off);
		offBtn.setOnClickListener(this);
	}

	@Override
	public void onClick(View v) {
		if (v == onBtn) {
//			open1();
			open2();
		} else if (v == offBtn) {
//			off1();
			off2();
		}
	}

	private void open1() {
		if (camera == null) {
			camera = Camera.open();
			params = camera.getParameters();
		}
		params.setFlashMode(Parameters.FLASH_MODE_TORCH);
		camera.setParameters(params);
	}

	private void off1() {
		if (camera == null) {
			return;
		}
		params.setFlashMode(Parameters.FLASH_MODE_OFF);
		camera.setParameters(params);
		camera.release();
		camera = null;
	}

	private void open2() {
		if (camera == null) {
			camera = Camera.open();
			params = camera.getParameters();
		}

		params.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
		camera.setParameters(params);
		camera.autoFocus(new Camera.AutoFocusCallback() {
			public void onAutoFocus(boolean success, Camera camera) {
			}
		});
		camera.startPreview();
	}

	private void off2() {
		if (camera == null) {
			return;
		}
		camera.stopPreview();
		camera.release();
		camera = null;
	}

}

权限：

    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.autofocus"/>