如何重用getExternalStorageState？ [英] How to Reuse getExternalStorageState?

问题描述

这怎么能写在自己的课堂上使用一遍又一遍？而且那里的注释行//加载列表是的，我需要能够改变在运行时。

日Thnx提前的时间信息。

  / **
 *  - 检查，看是否SD卡安装和放大器;加载有序列表
 * ================================================= =====================
 ** /
私人无效storageState（）{
    如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_MOUNTED））{

        orderASC（）; //加载列表

    }否则，如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_UNMOUNTED））{
        Alerts.sdCardMissing（本）;
    }
}
 

修订版：

 类StorageStateChecker {
  静态无效storageState（活动参数，侦听器l）{
    如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_MOUNTED））{

        l.orderASC_Label（）; //将清单按标签ASC
        l.orderDSC_Label（）;
        l.orderASC_Title（）; //将清单按标题ASC
        l.orderDSC_Title（）;

    }否则，如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_UNMOUNTED））{

            //传递上下文AlertDialog.Builder
            AlertDialog alertDialog =新AlertDialog.Builder（空）.create（）;
            alertDialog.setTitle（外部存储状态）;
            alertDialog.setMessage（你的SD卡没有安装如果设备插入电脑通过USB，请disconect设备！）;
            alertDialog.setButton（OK，新DialogInterface.OnClickListener（）{
                公共无效的onClick（DialogInterface对话，诠释它）{
                    //this.finish（）;
                }
            }）;
            // alertDialog.setIcon（R.drawable.icon）;
            alertDialog.show（）;
    }
  }

公共接口监听{
    公共无效orderASC_Label（）;
    公共无效orderDSC_Label（）;
    公共无效orderASC_Title（）;
    公共无效orderDSC_Title（）;
  }
}
 

解决方案

我会做这样的：

 公共静态布尔performExternalStorageOperation（Runnable的doIfMounted）{
    如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_MOUNTED））{

        orderASC（）; //加载列表
        如果（doIfMounted！= NULL）{
            doIfMounted.run（）;
        }
        返回true;
    }否则，如果（android.os.Environment.getExternalStorageState（）。等于（
            android.os.Environment.MEDIA_UNMOUNTED））{
        Alerts.sdCardMissing（本）;
    }
    返回false;
}
 

您可以替换了Runnable与任何一种通用的侦听器（我用OnClickListeners很多的不一定是点击操作）或者调用常用的方法编写自己的回调类，但是这将是我的一般方法。

How can this be written in its own class to be used over and over again? And where the comment line "//Loads the List" is, I need to be able to change that at runtime.

Thnx ahead of time for the info.

/**
 * -- Check to See if the SD Card is Mounted & Loads the Ordered List
 * ======================================================================
 **/
private void storageState() {
    if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_MOUNTED)) {

        orderASC();// Loads the list

    } else if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_UNMOUNTED)) {
        Alerts.sdCardMissing(this);
    }
}

REVISED:

class StorageStateChecker  {
  static void storageState(Activity param, Listener l) {
    if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_MOUNTED)) {

        l.orderASC_Label();//Load the list by Label ASC
        l.orderDSC_Label();
        l.orderASC_Title();//Load the list by Title ASC
        l.orderDSC_Title();

    } else if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_UNMOUNTED)) {

            // Pass context to AlertDialog.Builder
            AlertDialog alertDialog = new AlertDialog.Builder(null).create();
            alertDialog.setTitle("External Storage State");
            alertDialog.setMessage("Your SD-Card is not mounted!  If the device is plugged into a computer via the USB, please disconect the device.");
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    //this.finish();
                }
            });
            // alertDialog.setIcon(R.drawable.icon);
            alertDialog.show();
    }
  }

public interface Listener {
    public void orderASC_Label();
    public void orderDSC_Label();
    public void orderASC_Title();
    public void orderDSC_Title();
  }
}

解决方案

I would do this:

public static boolean performExternalStorageOperation(Runnable doIfMounted) {
    if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_MOUNTED)) {

        orderASC();// Loads the list
        if(doIfMounted != null) {
            doIfMounted.run();
        }
        return true;
    } else if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_UNMOUNTED)) {
        Alerts.sdCardMissing(this);
    }
    return false;
}

You can replace the Runnable with any kind of generic Listener (I use OnClickListeners a lot for actions that aren't necessarily clicks) or write your own callback class with a common method to call, but that would be my general approach.

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