android文件大小输出工具类

原文地址：http://blog.csdn.net/eyishion/article/details/51583950

根据文件大小自动转为以B,KB, MB, GB为单位的工具类.以后不用自己手动计算。 
贴一下源代码，看了之后，让你感觉倍爽：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> String <span class="hljs-title" style="box-sizing: border-box;">formatFileSize</span>(Context context, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">long</span> number)        {            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> formatFileSize(context, number, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</span>);        }        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> String <span class="hljs-title" style="box-sizing: border-box;">formatShortFileSize</span>(Context context, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">long</span> number)        {            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> formatFileSize(context, number, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);        }        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> String <span class="hljs-title" style="box-sizing: border-box;">formatFileSize</span>(Context context, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">long</span> number, boolean shorter)         {            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (context == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">""</span>;            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> result = number;            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.byteShort;            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">900</span>) {                suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.kilobyteShort;                result = result / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span>;            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">900</span>) {                suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.megabyteShort;                result = result / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span>;            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">900</span>) {                suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.gigabyteShort;                result = result / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span>;            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">900</span>) {                suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.terabyteShort;                result = result / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span>;            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">900</span>) {                suffix = com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.petabyteShort;                result = result / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span>;            }            String <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>;            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result < <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>) {                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.2f"</span>, result);            } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result < <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>) {                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (shorter) {                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.1f"</span>, result);                } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.2f"</span>, result);                }            } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (result < <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>) {                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (shorter) {                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.0f"</span>, result);                } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {                    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.2f"</span>, result);                }            } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {                <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span> = String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%.0f"</span>, result);            }            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> context.getResources().                getString(com.android.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">internal</span>.R.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">string</span>.fileSizeSuffix,                          <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">value</span>, context.getString(suffix));        }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li></ul>

自己试试一下，看看效果。在子线程里面操作

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Thread() {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">run</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">long</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>;         <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">do</span> {        Log.e(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"tag"</span>, Formatter.formatFileSize(MainActivity.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>, i));        Log.e(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"tag"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"short---"</span>+ Formatter.formatShortFileSize(MainActivity.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>,i));                    i *= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">102.4</span>;            } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span> (i < <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000000000</span>);        };        }.start();</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

打印的结果如下： 

以后计算文件大小就用它了,^_^