ReactNative与Android中的屏幕适配

前言：从开始接触rn到现在终于能写出点东西了，的确得为自己好好地点个赞 ，不管咋样，学习还是得继续啊，废话少说了，在rn中我们也需要对屏幕进行适配，但是rn中的适配貌似比android原生容易很多（不得佩服facebook那些大神哈，对android原生控件封装的太屌！）。

我们先看看rn中的屏幕适配（作为一个android程序员去做rn确实比ios程序员考虑的东西多一点点哈，嘻嘻～～）：

结合android的一些适配经验，我在rn中也封装了一个工具类

ScreenUtils.js：

/**
* 屏幕工具类
* ui设计基准,iphone 6
* width:750
* height:1334
*/
var ReactNative = require('react-native');
var Dimensions = require('Dimensions');
export var screenW = Dimensions.get('window').width;
export var screenH = Dimensions.get('window').height;
var fontScale = ReactNative.PixelRatio.getFontScale();
export var pixelRatio = ReactNative.PixelRatio.get();
const r2=2;
const w2 = 750/r2;``
const h2 = 1334/r2;
/**
* 设置text为sp
* @param size  sp
* @returns {Number} dp
*/
export const DEFAULT_DENSITY=2;
export function setSpText(size:Number) {
var scaleWidth = screenW / w2;
var scaleHeight = screenH / h2;
var scale = Math.min(scaleWidth, scaleHeight);
size = Math.round((size * scale + 0.5) * pixelRatio / fontScale);
return size;
}
/**
* 屏幕适配,缩放size
* @param size
* @returns {Number}
* @constructor
*/
export function scaleSize(size:Number) {
var scaleWidth = screenW / w2;
var scaleHeight = screenH / h2;
var scale = Math.min(scaleWidth, scaleHeight);
size = Math.round((size * scale + 0.5));
return size/DEFAULT_DENSITY;
}

搞过rn的童鞋知道，rn中直接写宽高都是dp的，所以我们要以一个美工设计的ui基准来计算我们的宽高，数学不好哈，不过大概是这样的：

我们先定义好ui的设计基准：

/**
* 屏幕工具类
* ui设计基准,iphone 6
* width:750
* height:1334
*/
var ReactNative = require('react-native');
var Dimensions = require('Dimensions');
export var screenW = Dimensions.get('window').width;
export var screenH = Dimensions.get('window').height;
var fontScale = ReactNative.PixelRatio.getFontScale();
export var pixelRatio = ReactNative.PixelRatio.get();
const r2=2;
const w2 = 750/r2;``
const h2 = 1334/r2;
/**
* 设置text为sp
* @param size  sp
* @returns {Number} dp
*/
export const DEFAULT_DENSITY=2;

然后获取到我们自己手机的屏幕宽高，生成一个百分比，然后算出在iphone6上的100px，在我们手机上是多少px，最后转换成dp设置在在我们布局的style中：

const styles = StyleSheet.create({
container: {
backgroundColor: 'white',
justifyContent: 'space-between',
flexDirection: 'row',
paddingTop: ScreenUtils.scaleSize(22),
paddingBottom: ScreenUtils.scaleSize(22),
paddingRight: ScreenUtils.scaleSize(12),
paddingLeft: ScreenUtils.scaleSize(12),
alignItems: 'center'
},
});

好啦～！！，rn上的适配就完啦，是不是soeasy呢？？？

但是在android原生中，我们写布局大多数都是在xml中写的，所以我们在写布局的时候，压根就不知道我要运行在什么手机上，所以android官方建议我们使用dp啊，然后建很多layout文件啊，很多value文件啊，是的！我个人也是比较推崇官方的做法的，效率高，清晰明了，好啦！！除了android官方说的那种方法，我们是否也可以像rn一样运行后再重新算出百分比，然后再布局呢？答案是肯定的，因为rn就是一个例子，它也是对原生控件封装过的，所以才能用js轻易控制，在此之前鸿洋大神也对百分比布局做了封装，也对齐做了很详细的解析了，先贴上大神的博客链接：

[(http://blog.csdn.net/lmj623565791/article/details/46767825]http://blog.csdn.net/lmj623565791/article/details/46767825](http://blog.csdn.net/lmj623565791/article/details/46767825

好啦！我们今天要做的也就是在百分比布局的基础上简单封装下，然后使得其能够像rn一样，直接写上美工标的px就能完美适配大部分手机了。

先上张运行好的效果图（效果还是很不错的！）：

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
tools:context="com.example.leo.textdemo.MainActivity">

<com.yasin.px_percent_layout.PercentLinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="10%w"
app:layout_heightPercent="10%h"
android:text="10%w,10%h"
android:background="#ff0000"
android:textColor="#fff"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="20%sw"
app:layout_heightPercent="20%sh"
android:text="屏幕宽的20%sw,屏幕高的20%sh"
android:background="#ffff00"
android:textColor="#ff00"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="200px"
app:layout_heightPercent="200px"
android:text="iphone6为基准的宽：200px，高：200px"
android:background="#0000ff"
android:textColor="#fff"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="375px"
app:layout_heightPercent="375px"
android:text="iphone6为基准的宽：370px，高：370px,textsize为28px"
android:background="#00ff00"
app:layout_textSizePercent="28px"
android:textColor="#ff00"
/>

</com.yasin.px_percent_layout.PercentLinearLayout>
</RelativeLayout>

先走一遍百分比布，看它到底是咋实现适配的(以下是来自鸿洋大神封装过后的代码，我就直接拿走解析了，嘻嘻！！)：

PercentLinearLayout.java:

package com.yasin.px_percent_layout;

import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.ScrollView;

public class PercentLinearLayout extends LinearLayout {

private static final String TAG = "PercentLinearLayout";
private PercentLayoutHelper mPercentLayoutHelper;

public PercentLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);

mPercentLayoutHelper = new PercentLayoutHelper(this);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int tmpHeightMeasureSpec = MeasureSpec.makeMeasureSpec(heightSize, heightMode);

int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int tmpWidthMeasureSpec = MeasureSpec.makeMeasureSpec(widthSize, widthMode);

//fixed scrollview height problems
if (heightMode == MeasureSpec.UNSPECIFIED && getParent() != null && (getParent() instanceof ScrollView)) {
int baseHeight = 0;
Context context = getContext();
if (context instanceof Activity) {
Activity act = (Activity) context;
int measuredHeight = act.findViewById(android.R.id.content).getMeasuredHeight();
baseHeight = measuredHeight;
} else {
baseHeight = getScreenHeight();
}
tmpHeightMeasureSpec = MeasureSpec.makeMeasureSpec(baseHeight, heightMode);
}

mPercentLayoutHelper.adjustChildren(tmpWidthMeasureSpec, tmpHeightMeasureSpec);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mPercentLayoutHelper.handleMeasuredStateTooSmall()) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

private int getScreenHeight() {
WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return outMetrics.heightPixels;
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
mPercentLayoutHelper.restoreOriginalParams();
}

@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}

public static class LayoutParams extends LinearLayout.LayoutParams
implements PercentLayoutHelper.PercentLayoutParams {
private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;

public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}

@Override
public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo() {
return mPercentLayoutInfo;
}

@Override
protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) {
PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr);
}

public LayoutParams(int width, int height) {
super(width, height);
}

public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}

public LayoutParams(MarginLayoutParams source) {
super(source);
}

}

}

代码不要太简单哈，就在构造方法中创建了一个mPercentLayoutHelper：

public PercentLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);

mPercentLayoutHelper = new PercentLayoutHelper(this);
}

我们待会再来说这个PercentLayoutHelper，

然后就是创建了一个自己的LayoutParams：

public static class LayoutParams extends LinearLayout.LayoutParams
implements PercentLayoutHelper.PercentLayoutParams {
private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;

public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}

@Override
public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo() {
return mPercentLayoutInfo;
}

@Override
protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr) {
PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr);
}

public LayoutParams(int width, int height) {
super(width, height);
}

public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}

public LayoutParams(MarginLayoutParams source) {
super(source);
}

}

其中也咩有啥代码，创建了一个PercentLayoutInfo。

然后核心代码就是onMeasure方法里面了：

mPercentLayoutHelper.adjustChildren(tmpWidthMeasureSpec, tmpHeightMeasureSpec);

核心也就这一句。

终结下来就是：

1、先获取到我们在布局文件中定义的属性：

app:layout_widthPercent="10%w"
app:layout_heightPercent="10%h"
.......

2、然后把获取到的属性封装进一个叫PercentLayoutInfo的类中：

public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}

3、在onMeasure方法中根据传进的属性对子控件进行重置大小：

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int tmpHeightMeasureSpec = MeasureSpec.makeMeasureSpec(heightSize, heightMode);

int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int tmpWidthMeasureSpec = MeasureSpec.makeMeasureSpec(widthSize, widthMode);

//fixed scrollview height problems
if (heightMode == MeasureSpec.UNSPECIFIED && getParent() != null && (getParent() instanceof ScrollView)) {
int baseHeight = 0;
Context context = getContext();
if (context instanceof Activity) {
Activity act = (Activity) context;
int measuredHeight = act.findViewById(android.R.id.content).getMeasuredHeight();
baseHeight = measuredHeight;
} else {
baseHeight = getScreenHeight();
}
tmpHeightMeasureSpec = MeasureSpec.makeMeasureSpec(baseHeight, heightMode);
}
mPercentLayoutHelper.adjustChildren(tmpWidthMeasureSpec, tmpHeightMeasureSpec);
super.onMeasure(widthMeasureSpec, hei }
}

看完是不是觉得很简单呢？ 是的，本来就不难哈，我们接着往下看：

先看看它是咋拿到我们在布局文件中写的属性的（怎么封装）：

public static PercentLayoutInfo getPercentLayoutInfo(Context context,
AttributeSet attrs) {
PercentLayoutInfo info = null;
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.PercentLayout_Layout);

info = setWidthAndHeightVal(array, info);

info = setMarginRelatedVal(array, info);

info = setTextSizeSupportVal(array, info);

info = setMinMaxWidthHeightRelatedVal(array, info);

info = setPaddingRelatedVal(array, info);

array.recycle();

if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "constructed: " + info);
}
return info;
}

获取TypedArray数组中的数据（我们就只看setWidthAndHeightVal代码了）：

private static PercentLayoutInfo setWidthAndHeightVal(TypedArray array, PercentLayoutInfo info) {
PercentLayoutInfo.PercentVal percentVal = getPercentVal(array, R.styleable.PercentLayout_Layout_layout_widthPercent, true);
if (percentVal != null) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "percent width: " + percentVal.percent);
}
info = checkForInfoExists(info);
info.widthPercent = percentVal;
}
percentVal = getPercentVal(array, R.styleable.PercentLayout_Layout_layout_heightPercent, false);

if (percentVal != null) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "percent height: " + percentVal.percent);
}
info = checkForInfoExists(info);
info.heightPercent = percentVal;
}

return info;
}

获取到heightPercent跟widthPercent信息然后赋给info对象，没啥好看的，重点看看咋获取到的widthPercent信息：

private static PercentLayoutInfo.PercentVal getPercentVal(TypedArray array, int index, boolean baseWidth) {
String sizeStr = array.getString(index);
PercentLayoutInfo.PercentVal percentVal = getPercentVal(sizeStr, baseWidth);
return percentVal;
}

也没啥看的（继续往下走）：

private static PercentLayoutInfo.PercentVal getPercentVal(String percentStr, boolean isOnWidth) {
//valid param
if (percentStr == null) {
return null;
}
Pattern p = Pattern.compile(REGEX_PERCENT);
Matcher matcher = p.matcher(percentStr);
if (TextUtils.isEmpty(percentStr) ||
(!matcher.matches() && !(percentStr.toLowerCase().endsWith("px")))) {
throw new RuntimeException("the value of layout_xxxPercent invalid! ==>" + percentStr);
}
String floatVal;
String lastAlpha;
float percent;
int len = percentStr.length();
if (matcher.matches()) {
//extract the float value
floatVal = matcher.group(1);
lastAlpha = percentStr.substring(len - 1);
percent = Float.parseFloat(floatVal) / 100f;
} else {
//extract the float value
floatVal = percentStr.substring(0, percentStr.indexOf("px"));
lastAlpha = percentStr.substring(len - 1);
percent = Float.parseFloat(floatVal);
}

PercentLayoutInfo.PercentVal percentVal = new PercentLayoutInfo.PercentVal();
percentVal.percent = percent;
if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.SW)) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_SCREEN_WIDTH;
} else if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.SH)) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_SCREEN_HEIGHT;
} else if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.PERCENT)) {
if (isOnWidth) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_WIDTH;
} else {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_HEIGHT;
}
} else if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.W)) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_WIDTH;
} else if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.H)) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.BASE_HEIGHT;
} else if (percentStr.endsWith(PercentLayoutInfo.BASEMODE.PX)) {
percentVal.basemode = PercentLayoutInfo.BASEMODE.ABSOLUTE_PX;
} else {
throw new IllegalArgumentException("the " + percentStr + " must be endWith [%|w|h|sw|sh]");
}

return percentVal;
}

好啦，终于看到核心代码了，不做太多解释，相信都看得懂，简单来说就是获取到我们设置的值，然后判断我们设置的值属于哪种类型：

类型有：

private enum BASEMODE {

BASE_WIDTH, BASE_HEIGHT, BASE_SCREEN_WIDTH, BASE_SCREEN_HEIGHT, ABSOLUTE_PX;

/**
* width_parent
*/
public static final String PERCENT = "%";
/**
* width_parent
*/
public static final String W = "w";
/**
* height_parent
*/
public static final String H = "h";
/**
* width_screen
*/
public static final String SW = "sw";
/**
* height_screen
*/
public static final String SH = "sh";
/**
* absolute px
*/
public static final String PX = "px";
}

就是我们布局中写的：

app:layout_widthPercent="10%w"
app:layout_heightPercent="10%h"
app:layout_widthPercent="20%sw"
app:layout_heightPercent="20%sh"
app:layout_widthPercent="200px"
app:layout_heightPercent="200px"

小伙伴是不是看懂了呢？ 比如20％sw，就是把20跟sw取出来，然后封装进类中。

好啦，我们已经拿到我们在布局中设置的属性了，然后我们就得根据我们设置的值重新赋给子控件了。

在onMeasure中我们找到adjustChildren方法：

/**
* Iterates over children and changes their width and height to one calculated from percentage
* values.
*
* @param widthMeasureSpec  Width MeasureSpec of the parent ViewGroup.
* @param heightMeasureSpec Height MeasureSpec of the parent ViewGroup.
*/
public void adjustChildren(int widthMeasureSpec, int heightMeasureSpec) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "adjustChildren: " + mHost + " widthMeasureSpec: "
+ View.MeasureSpec.toString(widthMeasureSpec) + " heightMeasureSpec: "
+ View.MeasureSpec.toString(heightMeasureSpec));
}
int widthHint = View.MeasureSpec.getSize(widthMeasureSpec);
int heightHint = View.MeasureSpec.getSize(heightMeasureSpec);

if (Log.isLoggable(TAG, Log.DEBUG))
Log.d(TAG, "widthHint = " + widthHint + " , heightHint = " + heightHint);

for (int i = 0, N = mHost.getChildCount(); i < N; i++) {
View view = mHost.getChildAt(i);
ViewGroup.LayoutParams params = view.getLayoutParams();

if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "should adjust " + view + " " + params);
}

if (params instanceof PercentLayoutParams) {
PercentLayoutInfo info =
((PercentLayoutParams) params).getPercentLayoutInfo();
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "using " + info);
}
if (info != null) {
supportTextSize(widthHint, heightHint, view, info);
supportPadding(widthHint, heightHint, view, info);
supportMinOrMaxDimesion(widthHint, heightHint, view, info);

if (params instanceof ViewGroup.MarginLayoutParams) {
info.fillMarginLayoutParams((ViewGroup.MarginLayoutParams) params,
widthHint, heightHint);
} else {
info.fillLayoutParams(params, widthHint, heightHint);
}
}
}
}
}

遍历我们的子控件，然后根据我们上面获取到的info类，进行重新布局：

if (info != null) {
supportTextSize(widthHint, heightHint, view, info);
supportPadding(widthHint, heightHint, view, info);
supportMinOrMaxDimesion(widthHint, heightHint, view, info);

if (params instanceof ViewGroup.MarginLayoutParams) {
info.fillMarginLayoutParams((ViewGroup.MarginLayoutParams) params,
widthHint, heightHint);
} else {
info.fillLayoutParams(params, widthHint, heightHint);
}
}

demo中我们看到了：

<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="375px"
app:layout_heightPercent="375px"
android:text="iphone6为基准的宽：370px，高：370px,textsize为28px"
android:background="#00ff00"
app:layout_textSizePercent="28px"
android:textColor="#ff00"
/>

我们有设置一个app:layout_textSizePercent：

看到这我们找到一个方法，没错！也就是这里对textview设置的size大小的：

supportTextSize(widthHint, heightHint, view, info);

我们往下走：

private void supportTextSize(int widthHint, int heightHint, View view, PercentLayoutInfo info) {
//textsize percent support

PercentLayoutInfo.PercentVal textSizePercent = info.textSizePercent;
if (textSizePercent == null) return;
float textSize;
int base = getBaseByModeAndVal(widthHint, heightHint, textSizePercent.basemode);
if (textSizePercent.basemode == PercentLayoutInfo.BASEMODE.ABSOLUTE_PX) {
textSize = ViewUtils.scaleTextValue(mHost.getContext(), textSizePercent.percent);
} else {
textSize = (int) (base * textSizePercent.percent);
}
//Button 和 EditText 是TextView的子类
if (view instanceof TextView) {
((TextView) view).setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
}
}

这里如果我们是直接设置的px的话（如：app:layout_textSizePercent=”28px”），我们就需要根据ui基准，然后算出在我们手机上应该显示多少：

int base = getBaseByModeAndVal(widthHint, heightHint, textSizePercent.basemode);
if (textSizePercent.basemode == PercentLayoutInfo.BASEMODE.ABSOLUTE_PX) {
textSize = ViewUtils.scaleTextValue(mHost.getContext(), textSizePercent.percent);
} else {
textSize = (int) (base * textSizePercent.percent);
}

如果是直接设置的20％w，20％h，20％sh这样的值的话，我们就需要用父布局的宽、高、屏幕宽、高乘一个我们设置进去的百分比进行计算了：

textSize = (int) (base * textSizePercent.percent);

好啦！！！剩下的几个方法也都差不多，我就不一一讲了哈：

if (info != null) {
supportTextSize(widthHint, heightHint, view, info);
supportPadding(widthHint, heightHint, view, info);
supportMinOrMaxDimesion(widthHint, heightHint, view, info);

if (params instanceof ViewGroup.MarginLayoutParams) {
info.fillMarginLayoutParams((ViewGroup.MarginLayoutParams) params,
widthHint, heightHint);
} else {
info.fillLayoutParams(params, widthHint, heightHint);
}
}

嗯嗯～！ 我们的百分比跟px布局差不多就讲完啦～， 下面看看咋使用它哈：

如果要直接使用px布局的话（不用px布局可不需要做第一步与第二步）：

1、在项目的manifest文件中定义好ui设计的基准（如iphone6）：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.leo.textdemo" >

<application
android:name=".BaseApplication"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"
>
<meta-data android:name="UI_WIDTH" android:value="750"/>
<meta-data android:name="UI_HEIGHT" android:value="1334"/>
<meta-data android:name="UI_DENSITY" android:value="2"/>
<activity android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SimpleMenuActivtiy">
</activity>
</application>

</manifest>

2、在app中的application文件中，初始化布局：

package com.example.leo.textdemo;

import android.app.Application;
import android.content.Context;

import com.yasin.px_percent_layout.utils.PxAppConfig;

/**
* Created by leo on 17/2/9.
*/

public class BaseApplication extends Application {
@Override
protected void attachBaseContext(Context base) {
super.attachBaseContext(base);
PxAppConfig.init(base);
}
}

然后我们就可以在布局文件中用起来了：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
tools:context="com.example.leo.textdemo.MainActivity">

<com.yasin.px_percent_layout.PercentLinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="10%w"
app:layout_heightPercent="10%h"
android:text="10%w,10%h"
android:background="#ff0000"
android:textColor="#fff"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="20%sw"
app:layout_heightPercent="20%sh"
android:text="屏幕宽的20%sw,屏幕高的20%sh"
android:background="#ffff00"
android:textColor="#ff00"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="200px"
app:layout_heightPercent="200px"
android:text="iphone6为基准的宽：200px，高：200px"
android:background="#0000ff"
android:textColor="#fff"
/>
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_widthPercent="375px"
app:layout_heightPercent="375px"
android:text="iphone6为基准的宽：370px，高：370px,textsize为28px"
android:background="#00ff00"
app:layout_textSizePercent="28px"
android:textColor="#ff00"
/>

</com.yasin.px_percent_layout.PercentLinearLayout>
</RelativeLayout>

好啦！！！文章有点长哈，最后附上项目的git链接：

https://github.com/913453448/PercentLayoutDemo