android.os.Environment#MEDIA_MOUNTED源码实例Demo

private static boolean isStorageWritable() {
    boolean isExternalStorageAvailable;
    boolean isExternalStorageWritable;
    String state = Environment.getExternalStorageState();
    switch (state) {
        case Environment.MEDIA_MOUNTED:
            isExternalStorageAvailable = true;
            isExternalStorageWritable = true;
            break;
        case Environment.MEDIA_MOUNTED_READ_ONLY:
            isExternalStorageAvailable = true;
            isExternalStorageWritable = false;
            break;
        default:
            isExternalStorageAvailable = false;
            isExternalStorageWritable = false;
            break;
    }
    return isExternalStorageAvailable && isExternalStorageWritable;
}
 

private void initiImageLoader() {
    DisplayImageOptions options = new DisplayImageOptions.Builder()
            .bitmapConfig(Bitmap.Config.RGB_565)
            .imageScaleType(ImageScaleType.EXACTLY)
            .cacheOnDisc(true)
            .displayer(new FadeInBitmapDisplayer(200))
            .showImageOnLoading(R.drawable.ic_launcher)
            .build();

    File cacheDir;
    if(Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED){
        cacheDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    }else{
        cacheDir = getCacheDir();
    }
    ImageLoaderConfiguration.Builder configBuilder = new ImageLoaderConfiguration.Builder(mContext)
            .threadPoolSize(2)
            .memoryCache(new WeakMemoryCache())
            .denyCacheImageMultipleSizesInMemory()
            .discCache(new UnlimitedDiscCache(cacheDir))
            .defaultDisplayImageOptions(options);
    if(BuildConfig.DEBUG){
        configBuilder.writeDebugLogs();
    }
    ImageLoader.getInstance().init(configBuilder.build());
}
 

public static File getDiskCacheDir(final Context context, final String uniqueName) {
    // Check if media is mounted or storage is built-in, if so, try and use external cache dir
    // otherwise use internal cache dir
    final boolean externalCacheAvailable = (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) ||
                                           !Utils.isExternalStorageRemovable();

    String cachePath = null;

    if (externalCacheAvailable && Utils.getExternalCacheDir(context) != null) {
        cachePath = Utils.getExternalCacheDir(context).getPath();
    } else {
        cachePath = context.getCacheDir().getPath();
    }

    return new File(cachePath + File.separator + uniqueName);
}
 

private static File prepareTargetDirectory() throws DownloadFailException, IOException {
    File downloadFolder =
            Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
    if (
            downloadFolder
                    != null
                    && (downloadFolder.exists() || downloadFolder.mkdir() || downloadFolder.createNewFile())
                    && downloadFolder.canWrite()
    ) {
        return downloadFolder;
    }

    File externalStorage = Environment.getExternalStorageDirectory();
    String externalStorageState = Environment.getExternalStorageState();
    if (
            externalStorage
                    != null
                    && (externalStorage.exists() || externalStorage.mkdir() || externalStorage.createNewFile())
                    && externalStorage.canWrite()
                    && externalStorageState.equals(Environment.MEDIA_MOUNTED)
    ) {
        return new File(externalStorage, "Download");
    }

    File appExternal = LMvdApp.getInstance().getExternalFilesDir(null);
    if (
            appExternal
                    != null
                    && (appExternal.exists() || appExternal.mkdir() || appExternal.createNewFile())
                    && appExternal.canWrite()
    ) {
        return new File(appExternal, "Download");
    }

    String message;
    switch (externalStorageState) {
        case Environment.MEDIA_UNMOUNTABLE:
            message = "External storage is un-mountable.";
            break;
        case Environment.MEDIA_SHARED:
            message = "USB mass storage is turned on. Can not mount external storage.";
            break;
        case Environment.MEDIA_UNMOUNTED:
            message = "External storage is not mounted.";
            break;
        case Environment.MEDIA_MOUNTED_READ_ONLY:
            message = "External storage is mounted but has no write access.";
            break;
        case Environment.MEDIA_BAD_REMOVAL:
            message = "External storage was removed without being properly ejected.";
            break;
        case Environment.MEDIA_REMOVED:
            message = "External storage does not exist. Probably removed.";
            break;
        case Environment.MEDIA_NOFS:
            message = "External storage is blank or has unsupported filesystem.";
            break;
        case Environment.MEDIA_CHECKING:
            message = "Still checking for external storage.";
            break;
        case Environment.MEDIA_EJECTING:
            message = "External storage is currently being ejected.";
            break;
        case Environment.MEDIA_UNKNOWN:
            message = "External storage is not available for some unknown reason.";
            break;
        case Environment.MEDIA_MOUNTED:
            message = "External storage is mounted but for some unknown reason is not" +
                    " available.";
            break;
        default:
            message = "External storage is not available. No reason.";
    }
    throw new DownloadFailException(message);
}
 

@Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.set_path_button:
                mFontTextView.setFontPath("fonts/my_font.ttf");
                break;
            case R.id.create_button:
                v.setEnabled(false);    // can click only once
                ViewGroup parent = (ViewGroup) findViewById(R.id.container_layout);
                createFontTextView(parent, "fonts/my_font.ttf");
//                createTextView(parent, "fonts/my_font.ttf");
                break;
            case R.id.replace_font_from_asset_btn:
                /* Method 3: replace system default font */
                FontUtils.getInstance().replaceSystemDefaultFontFromAsset(this, "fonts/my_font.ttf");
                recreate();
                break;
            case R.id.replace_font_from_file_btn:
                if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
                    String fontPath = Environment.getExternalStorageDirectory() + "/whinc/my_font.ttf";
                    FontUtils.getInstance().replaceSystemDefaultFontFromFile(this, fontPath);
                    recreate();
                } else {
                    Toast.makeText(this, "External storage is not accessible!", Toast.LENGTH_SHORT).show();
                }
                break;
            case R.id.add_view_btn:
                v.setEnabled(false);    // can click only once
                Button button = new Button(this, null, R.attr.buttonStyle);
                button.setText("Button");
                RelativeLayout layout = (RelativeLayout) findViewById(R.id.font_text_layout);
                RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                        ViewGroup.LayoutParams.WRAP_CONTENT,
                        ViewGroup.LayoutParams.WRAP_CONTENT
                );
                lp.addRule(RelativeLayout.CENTER_IN_PARENT);
                layout.addView(button, lp);
                break;
            default:
                break;
        }
    }
 

/**
 * 判断sdcard是否已经挂载
 * @param context
 * @return
 */
public static boolean hasSdcard(Context context){
    return  Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED;
}
 

/**
 * 判断sdcard是否已经挂载
 * @param context
 * @return
 */
public static boolean hasSdcard(Context context){
    return  Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED;
}