我使用的是相机的闪光灯在我​​的申请，我做编码为，它的工作开/关灯。但在2秒钟后它去了。如果我按钮preSS再次它被赋予强制关闭。这是code我用这个，请帮助我。

我想这就像如果用户presses的按钮指示灯亮起，用户高达preSS关按钮。

 私人无效processOffClick（）{    //togglebutton.setButtonDrawable(R.drawable.offbutton）;    的System.out.println（关机状态）;    如果（凸轮！= NULL）{        cam.stop preVIEW（）;        cam.release（）;    }}私人无效processOnClick（）{    //togglebutton.setButtonDrawable(R.drawable.onbutton）;    的System.out.println（在国家）;    凸轮= Camera.open（）;    参数PARAMS = cam.getParameters（）;    params.setFlashMode（Parameters.FLASH_MODE_ON）;    cam.setParameters（PARAMS）;    cam.start preVIEW（）;    cam.autoFocus（新AutoFocusCallback（）{        公共无效onAutoFocus（布尔成功，相机摄像头）{        }    }）;} 

解决方案

把行：

 参数PARAMS = cam.getParameters（）;params.setFlashMode（Parameters.FLASH_MODE_ON）;cam.setParameters（PARAMS）; 

的在processOffClick，而不是把它processOnClick这样的：

 布尔点击= FALSE;私人无效processOffClick（）{  //togglebutton.setButtonDrawable(R.drawable.offbutton）;  点击= FALSE;  的System.out.println（关机状态）;  如果（凸轮！= NULL）{      cam.stop preVIEW（）;      cam.release（）;  }}私人无效processOnClick（）{  点击= TRUE;  //togglebutton.setButtonDrawable(R.drawable.onbutton）;  的System.out.println（在国家）;  凸轮= Camera.open（）;  参数PARAMS = cam.getParameters（）;  params.setFlashMode（Parameters.FLASH_MODE_ON）;  而（点击）{     cam.setParameters（PARAMS）;     cam.start preVIEW（）;        cam.autoFocus（新AutoFocusCallback（）{           公共无效onAutoFocus（布尔成功，相机摄像头）{        }     }）;  }} 

这可能会工作，我没有检查code

我添加了一个while循环，以便将举行闪光灯和对焦直到未点击。

I am using the camera flash light in my application, I was done coding for that, it's working on/off the light. but after 2 seconds it goes to off. If I press the on button again it was giving force close. This is the code i am using for this, please help me.

I want this like if user presses the on button light On, upto user press Off button.

private void processOffClick()  {

    //togglebutton.setButtonDrawable(R.drawable.offbutton);
    System.out.println("in off state");
    if( cam != null ){
        cam.stopPreview();
        cam.release();
    }
}
private void processOnClick()  {

    //togglebutton.setButtonDrawable(R.drawable.onbutton);
    System.out.println("in on state");       
    cam = Camera.open();     
    Parameters params = cam.getParameters();
    params.setFlashMode(Parameters.FLASH_MODE_ON);
    cam.setParameters(params);

    cam.startPreview();
    cam.autoFocus(new AutoFocusCallback() {
        public void onAutoFocus(boolean success, Camera camera) {
        }
    });      
}

put the lines:

Parameters params = cam.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_ON);
cam.setParameters(params);

in processOffClick instead of putting it in processOnClick like that:

boolean clicked = false;
private void processOffClick()  {

  //togglebutton.setButtonDrawable(R.drawable.offbutton);
  clicked = false;
  System.out.println("in off state");
  if( cam != null ){
      cam.stopPreview();
      cam.release();
  }
}
private void processOnClick()  {
  clicked = true;
  //togglebutton.setButtonDrawable(R.drawable.onbutton);
  System.out.println("in on state");       
  cam = Camera.open();     
  Parameters params = cam.getParameters();
  params.setFlashMode(Parameters.FLASH_MODE_ON);

  while(clicked)  { 
     cam.setParameters(params);

     cam.startPreview();
        cam.autoFocus(new AutoFocusCallback() {
           public void onAutoFocus(boolean success, Camera camera) {
        }
     });
  } 
}

It might work, i didn't check the code

I added a while loop so it would hold the flash and the focus until its unclicked.