Android 使用正则表达式来快速生成多套dpi及分分辨率适配的UI

　在Android开发中，往往为了适配dpi和分辨率，要写多套layout或者values，而鉴于dpi和分辨率的计算方式，很多时候适配的大部分工作都是简单的计算方面。譬如DPI从1.5到2.0，就是将所有dip、sp为单位的数值都乘以0.75（也就是1.5/2）。所以我们完成可以自己写一个小工具来批量读取layout或者values文件，然后进行批量操作并保存。

　　对文件的批量打开读取操作我这里就不浪费周章了，大家可以自行查阅资料，这里主要贴出核心代码。

<pre style="margin-top: 0px; margin-bottom: 0px; padding: 0px; white-space: pre-wrap; word-wrap: break-word; line-height: 21.6000003814697px; font-family: 'Courier New' !important;"> FileInputStream inputStream = <span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">new</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> FileInputStream(subFile);
BufferedReader reader </span>= <span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">new</span> BufferedReader(<span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">new</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> InputStreamReader(
inputStream));
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">if</span> (sb == <span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">null</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">) {
sb </span>= <span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">new</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> StringBuffer();
}
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">for</span> (String s = reader.readLine(); s != <span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">null</span>; s =<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> reader.readLine()) {
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 128, 0); line-height: 1.5 !important;">//</span><span style="margin: 0px; padding: 0px; color: rgb(0, 128, 0); line-height: 1.5 !important;"> 使用的是逐行读取，所以xml的格式必须每行都是完整的，不然会出现各种意想不到的结果。</span>
String temp =<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> s;
Pattern dpPattern </span>= Pattern.compile("\"(.+?)dp\""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
Matcher dpMatcher </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> dpPattern.matcher(temp);
System.out.println(s);
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">if</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> (dpMatcher.find()) {
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">for</span> (<span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">int</span> gNum = 1; gNum <= dpMatcher.groupCount(); gNum++<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">) {
System.out.println(</span>"dp"<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
System.out.println(dpMatcher.group(gNum));
temp </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> temp.replaceAll(dpMatcher.group(gNum),
Float.parseFloat(dpMatcher.group(gNum))
</span>* CHANGE_RATIO + ""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
}
}
Pattern dipPattern </span>= Pattern.compile("\"(.+?)dip\""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
Matcher dipMatcher </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> dipPattern.matcher(temp);
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">if</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> (dipMatcher.find()) {
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">for</span> (<span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">int</span> gNum = 1; gNum <= dipMatcher.groupCount(); gNum++<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">) {
System.out.println(</span>"dip"<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
System.out.println(dipMatcher.group(gNum));
temp </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> temp.replaceAll(dipMatcher.group(gNum),
Float.parseFloat(dipMatcher.group(gNum))
</span>* CHANGE_RATIO + ""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
}
}
Pattern spPattern </span>= Pattern.compile("\"(.+?)sp\""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
Matcher spMatcher </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> spPattern.matcher(temp);
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">if</span><span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> (spMatcher.find()) {
</span><span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">for</span> (<span style="margin: 0px; padding: 0px; color: rgb(0, 0, 255); line-height: 1.5 !important;">int</span> gNum = 1; gNum <= spMatcher.groupCount(); gNum++<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">) {
System.out.println(</span>"sp"<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
System.out.println(spMatcher.group(gNum));
temp </span>=<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;"> temp.replaceAll(spMatcher.group(gNum),
Float.parseFloat(spMatcher.group(gNum))
</span>* CHANGE_RATIO + ""<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
}
}
sb.append(temp </span>+ "\n"<span style="margin: 0px; padding: 0px; line-height: 1.5 !important;">);
}</span>

通过上述代码，我们可以发现逻辑很简单，就是找出“xxxdp”里面xxx的值，然后乘以一个转化系数CHANGE_RATIO而已，当我们要将dpi从1.5转成2.0的时候，就可以这么做了~该正则表达式适用于批量修改layout里的数值。如果是修改values里的dimens数值的话，我们可以将对应语句换为

Pattern dpPattern = Pattern.compile(">(.+?)dp<");

大家可以多开发一点这样的小工具，来提高平时的工作效率~