android开启闪光灯
Ⅰ Android如何打开闪光灯
一、声明闪光灯的权限
<uses-permissionandroid:name="android.permission.CAMERA"/>
<uses-permissionandroid:name="android.permission.FLASHLIGHT"/>
package com.google.yang.myapplication;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
* 闪光灯的控制
*
* @author yang
*/
public class MainActivity extends AppCompatActivity {
private Button open;
private Button close;
private Button openFlicker;
private Button closeFlicker;
private Camera camera;
private Boolean isShanshuo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
open = (Button) this.findViewById(R.id.open);
close = (Button) this.findViewById(R.id.close);
openFlicker = (Button) findViewById(R.id.openFlicker);
closeFlicker = (Button) findViewById(R.id.closeFlicker);
open.setOnClickListener(openOnClickListener);
close.setOnClickListener(closeOnClickListener);
openFlicker.setOnClickListener(openFlickerOnClickListener);
closeFlicker.setOnClickListener(closeFlickerOnClickListener);
}
/**
* 打开手电筒
*/
private OnClickListener openOnClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
open();
}
};
/**
* 关闭手电筒
*/
private OnClickListener closeOnClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
close();
}
};
/**
* 开启闪烁
*/
private OnClickListener openFlickerOnClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
isShanshuo = true;
openFlicker.setEnabled(false);
new Thread(new Runnable() {
@Override
public void run() {
while (isShanshuo) {
open();
try {
Thread.sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
close();
try {
Thread.sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
};
/**
* 关闭闪烁
*/
private OnClickListener closeFlickerOnClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
isShanshuo = false;
openFlicker.setEnabled(true);
}
};
/**
* 打开闪光灯
*
* @return
*/
private void open() {
try {
camera = Camera.open();
camera.startPreview();
Parameters parameters = camera.getParameters();
parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(parameters);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 关闭闪光灯
*
* @return
*/
private void close() {
try {
Parameters parameters = camera.getParameters();
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
camera.setParameters(parameters);
camera.release();
camera = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
Ⅱ 如何在android中使用闪光灯
下图是android学习手册中的介绍截图，例子、文档、源码随便看。
用IHardwareService直接控制Android1.5以前是直接提供这个接口的，之后呢，需要我们自己来做一下。在你的项目中新建一个包Android.os,新建一个IHardwareService.aidl文件，内容如下：package Android.os;
/** {@hide} */
interface IHardwareService{// obsolete flashlight support
boolean getFlashlightEnabled();
void setFlashlightEnabled(boolean on);}然后在你的程序中引入import Android.os.IHardwareService;/*** 设置闪光灯的开启和关闭
* @param isEnable
* @author linc
IBinder binder = (IBinder) method.invoke(null, new Object[] { "hardware" });
IHardwareService localhardwareservice = IHardwareService.Stub.asInterface(binder);
localhardwareservice.setFlashlightEnabled(isEnable);}catch (Exception e){
e.printStackTrace();}}这样就可以开启闪光灯了。要使用的权限：<uses-permission Android:name="android.permission.FLASHLIGHT" />
<uses-permission Android:name="android.permission.HARDWARE_TEST" />
三、用照相机来控制闪光灯这是思维的另一个方向。Camera自带丰富的接口与Parameters，我们只管拿来使用就好了。private Camera camera = null;
private Parameters parameters = null;//直接开启camera = Camera.open();
parameters = camera.getParameters();
parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);//开启
camera.setParameters(parameters);//直接关闭parameters.setFlashMode(Parameters.FLASH_MODE_OFF);//关闭
camera.setParameters(parameters);
camera.release();
如果这样遇到问题的话，可以尝试用camera的preview方法：private void OpenLightOn() {
if ( null == m_Camera ){m_Camera = Camera.open();}
Camera.Parameters parameters = m_Camera.getParameters();
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
m_Camera.setParameters( parameters );
m_Camera.autoFocus( new Camera.AutoFocusCallback (){
public void onAutoFocus(boolean success, Camera camera) {}});m_Camera.startPreview();}
private void CloseLightOff() {
if ( m_Camera != null ){m_Camera.stopPreview();
Ⅲ android 如何调控闪光灯亮度
这是与设备相关的，因为硬件厂商才能自行定义硬件的属性。比如htc为相机闪光灯设置一个亮度文件，通过改写这个文件的值，可以达到变更相机闪光灯的亮度，魅族应该也是这样操作的。作为安卓系统来说，没有统一的解决方案的。
参考htc闪光灯亮度root下的设置方法：
on 2.2 HTC devices you can use it by writing a string to/sys/devices/platform/flashlight.0/leds/flashlight/brightness. This controls if the LED is on and how bright it is. For maximum brightness write "128\n", half brightness write "64\n". Easy to test from adb shell: