CommonUtil.java

package edu.hebtu.movingcampus.utils;

import java.io.File;

import android.content.Context;
import android.os.Environment;
import android.os.StatFs;

public class CommonUtil {

	/**
	 * 检测sdcard是否可用
	 * 
	 * @return true为可用，否则为不可用
	 */
	public static boolean sdCardIsAvailable() {
		String status = Environment.getExternalStorageState();
		if (!status.equals(Environment.MEDIA_MOUNTED))
			return false;
		return true;
	}

	/**
	 * Checks if there is enough Space on SDCard
	 * 
	 * @param updateSize
	 *            Size to Check
	 * @return True if the Update will fit on SDCard, false if not enough space
	 *         on SDCard Will also return false, if the SDCard is not mounted as
	 *         read/write
	 */
	public static boolean enoughSpaceOnSdCard(long updateSize) {
		String status = Environment.getExternalStorageState();
		if (!status.equals(Environment.MEDIA_MOUNTED))
			return false;
		return (updateSize < getRealSizeOnSdcard());
	}

	/**
	 * get the space is left over on sdcard
	 */
	public static long getRealSizeOnSdcard() {
		File path = new File(Environment.getExternalStorageDirectory()
				.getAbsolutePath());
		StatFs stat = new StatFs(path.getPath());
		long blockSize = stat.getBlockSize();
		long availableBlocks = stat.getAvailableBlocks();
		return availableBlocks * blockSize;
	}

	/**
	 * Checks if there is enough Space on phone self
	 * 
	 */
	public static boolean enoughSpaceOnPhone(long updateSize) {
		return getRealSizeOnPhone() > updateSize;
	}

	/**
	 * get the space is left over on phone self
	 */
	public static long getRealSizeOnPhone() {
		File path = Environment.getDataDirectory();
		StatFs stat = new StatFs(path.getPath());
		long blockSize = stat.getBlockSize();
		long availableBlocks = stat.getAvailableBlocks();
		long realSize = blockSize * availableBlocks;
		return realSize;
	}

	/**
	 * 根据手机分辨率从dp转成px
	 * 
	 * @param context
	 * @param dpValue
	 * @return
	 */
	public static int dip2px(Context context, float dpValue) {
		final float scale = context.getResources().getDisplayMetrics().density;
		return (int) (dpValue * scale + 0.5f);
	}

	/**
	 * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
	 */
	public static int px2dip(Context context, float pxValue) {
		final float scale = context.getResources().getDisplayMetrics().density;
		return (int) (pxValue / scale + 0.5f) - 15;
	}

}