百分比布局让其中的控件在指定高度，宽度，margin时使用屏幕宽高的百分比，不使用dp,px。这样一套布局可以适应多个屏幕，方便适配。如：
app:layout_heightPercent="30%"
它们分别为
图1. 2.7''_
240*320:ldpi 图2. 4.0''_480*800:hdpi 图3. 5.5''_1440*2560:560dpi 图4. 8.86''_2048*1536:xhdpi
点击可看原图
根百分比布局背景色 ：#c2c2c2
其它百分比布局背景色：#8b0a50
2. ConstraintLayout
实现百分比布局
PercentRelativeLayout等百分比布局与 ConstraintLayout 等不兼容, ConstraintLayout 支持的百分比方法有下面几种：
Guideline .
bias : app:layout_constraintHorizontal_bias="0.3" 和 app:layout_constraintVertical_bias="0.3"
百分比值 : app:layout_constraintWidth_percent="0.4" 和 app:layout_constraintHeight_percent="0.9"
宽高比 : app:layout_constraintDimensionRatio
2.1 Guideline.
1 <android.support.constraint.Guideline
2 android:id="@+id/guideline"
3 android:layout_width="wrap_content"
4 android:layout_height="wrap_content"
5 android:orientation="vertical"
6 app:layout_constraintGuide_percent="0.3046875" />
8 <TextView
9 android:id="@+id/txt_args_minimumLatency"
10 android:layout_width="0dp"
11 android:layout_height="wrap_content"
12 android:layout_marginEnd="8dp"
13 android:layout_marginLeft="8dp"
14 android:layout_marginRight="8dp"
15 android:layout_marginStart="8dp"
16 android:layout_marginTop="16dp"
17 android:gravity="end|center_vertical"
18 android:text="最小反应时间 : "
19 app:layout_constraintEnd_toStartOf="@+id/guideline"
20 app:layout_constraintStart_toStartOf="parent"
21 app:layout_constraintTop_toBottomOf="@+id/txt_arg_connectivity" />
2.2 bias
同时指定左右方相对约束后，可以指定在左右之间的百分比。
app:layout_constraintHorizontal_bias="0.9"
上下同理。
app:layout_constraintVertical_bias="0.8"
1 <?xml version="1.0" encoding="utf-8"?>
2 <androidx.constraintlayout.widget.ConstraintLayout
3 xmlns:android="http://schemas.android.com/apk/res/android"
4 xmlns:tools="http://schemas.android.com/tools"
5 xmlns:app="http://schemas.android.com/apk/res-auto"
6 android:layout_width="match_parent"
7 android:layout_height="match_parent"
8 tools:context=".MainActivity">
10 <TextView
11 android:layout_width="wrap_content"
12 android:layout_height="wrap_content"
13 android:text="Hello World!"
14 app:layout_constraintVertical_bias="0.8"
15 app:layout_constraintHorizontal_bias="0.9"
16 app:layout_constraintBottom_toBottomOf="parent"
17 app:layout_constraintLeft_toLeftOf="parent"
18 app:layout_constraintRight_toRightOf="parent"
19 app:layout_constraintTop_toTopOf="parent"/>
21 </androidx.constraintlayout.widget.ConstraintLayout>
2.3 百分比值
用app:layout_constraintWidth_percent="0.4" 和 app:layout_constraintHeight_percent="0.9" 设置该控件相对父布局的百分比大小。
注意：在 android:layout_width="0dp" 时，app:layout_constraintWidth_percent="0.4"才生效，高度百分比同理。
1 <Button
2 android:id="@+id/btn_login"
3 android:layout_width="0dp"
4 app:layout_constraintWidth_percent="0.4"
5 android:layout_height="0dp"
6 app:layout_constraintHeight_percent="0.9"
7 android:layout_marginStart="8dp"
8 android:layout_marginTop="8dp"
9 android:layout_marginEnd="8dp"
10 android:layout_marginBottom="8dp"
11 android:background="@drawable/selector_login_button"
12 android:enabled="false"
13 android:maxLength="32"
14 android:maxLines="1"
15 android:text="登录"
16 android:textColor="#fff"
17 android:textSize="15sp"
18 app:layout_constraintBottom_toBottomOf="parent"
19 app:layout_constraintEnd_toEndOf="parent"
20 app:layout_constraintStart_toStartOf="parent"
21 app:layout_constraintTop_toTopOf="parent"
22 />
2.4 宽高比
宽度/高度的比值：app:layout_constraintDimensionRatio，注意宽、高中必需有一个是0dp，才可以。使用它可以根据宽算高，或者根据高算宽。
1 <ImageView
2 android:id="@+id/finish_delete_icon"
3 android:layout_width="22dp"
4 android:layout_height="0dp"
5 app:layout_constraintDimensionRatio="0.5"
6 android:src="@mipmap/delete"
7 android:textColor="@color/title_color"
8 app:layout_constraintEnd_toEndOf="parent"
9 app:layout_constraintHorizontal_bias="0.33"
10 app:layout_constraintStart_toStartOf="parent"
11 app:layout_constraintTop_toTopOf="parent"
12 />
2.5 如何用代码修改百分比布局
1 @Override
2 public void onKeyboardChange(boolean isShow, int keyboardHeight) {
3 ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams) mBtnLogin.getLayoutParams();
4 if (isShow ) {
5 params.matchConstraintPercentWidth = 0.8f; //修改百分比宽度
6 params.verticalBias = 0.93f; //修改百分比位置，横向同理
7 } else {
8 params.matchConstraintPercentWidth = 0.3f; //修改百分比宽度
9 params.verticalBias = 0.65f; //修改百分比位置，横向同理
10 }
12 /*
13 //其它同理 ,如:
14 params.guidePercent = 0.3f;
15 params.verticalWeight = 2;
16 */
18 mBtnLogin.setLayoutParams(params);
上方红底白字是percent支援包版本号，在sdk/extras/android/m2repository/com/android/support/percent/ 目录下有详细的版本。
可以使用 26.+ 也可以使用具体版本号如：26.0.0-alpha1 .
4.常用百分比布局
PercentRelativeLayout
相对百分比布局
PercentFrameLayout
相对层百分比布局
PercentLinearLayout
相对线性百分比布局，这个在com.android.support:percent中没有，本文提供代码。把它加到项目中就可以。
5.百分比布局属性
5.1 属性表
app:layout_widthPercent
控件宽度百分比（相对屏幕宽度）
app:layout_widthPercent="100%"
app:layout_heightPercent
控件高度百分比（相对屏幕高度）
app:layout_heightPercent="50%"
5.2 注意事项
app:layout_marginStartPercent="10%"与 app:layout_marginEndPercent="10%" 成对出现指定最大宽度
app:layout_marginLeftPercent="30%" 与 app:layout_marginRightPercent="30%"成对出现指定最大宽度
只要layout_marginStartPercent 这对中出现一个，则layout_marginLeftPercent 这对无效。
app:layout_xxx与android:layout_xxx 在指定相同含义（如都指定左边距）时，取app:layout_xxx的值。
最好只使用百分比系列的属性，也可混合使用。
1 app:layout_marginRightPercent="30%"
2 android:layout_marginLeft="5dp"
6.相对百分比布局
1 <?xml version="1.0" encoding="utf-8"?>
2 <android.support.percent.PercentRelativeLayout
3 xmlns:android="http://schemas.android.com/apk/res/android"
4 xmlns:app="http://schemas.android.com/apk/res-auto"
5 android:layout_width="match_parent"
6 android:layout_height="match_parent">
9 <ImageButton
10 android:id="@+id/imageButton"
12 app:layout_widthPercent="30%"
13 app:layout_heightPercent="30%"
15 app:layout_marginLeftPercent="20%"
16 app:layout_marginRightPercent="20%"
18 app:layout_marginStartPercent="10%"
19 app:layout_marginEndPercent="10%"
21 app:layout_marginTopPercent="10%"
22 app:layout_marginBottomPercent="10%"
24 app:srcCompat="@android:drawable/ic_notification_overlay" />
26 <ImageView
27 android:id="@+id/imageView"
29 app:layout_widthPercent="30%"
30 app:layout_heightPercent="30%"
33 app:layout_marginLeftPercent="50%"
34 app:layout_marginRightPercent="10%"
36 app:layout_marginTopPercent="10%"
37 app:layout_marginBottomPercent="10%"
39 app:srcCompat="@drawable/qq" />
42 <com.google.android.gms.maps.MapView
43 android:id="@+id/mapView"
44 android:background="#d3a16c"
46 app:layout_widthPercent="100%"
47 app:layout_heightPercent="50%"
49 app:layout_marginLeftPercent="10%"
50 app:layout_marginRightPercent="10%"
52 app:layout_marginStartPercent="3%"
53 app:layout_marginEndPercent="3%"
55 app:layout_marginTopPercent="5%"
56 app:layout_marginBottomPercent="5%"
58 android:layout_alignParentBottom="true" />
60 </android.support.percent.PercentRelativeLayout>
7.层百分比布局
1 <?xml version="1.0" encoding="utf-8"?>
2 <android.support.percent.PercentFrameLayout
3 xmlns:android="http://schemas.android.com/apk/res/android"
4 xmlns:app="http://schemas.android.com/apk/res-auto"
5 android:layout_width="match_parent"
6 android:layout_height="match_parent">
7 <!-- ... XML CODE -->
9 <TextView
10 android:id="@+id/textView"
12 android:text="hello"
13 android:textAlignment="center"
15 app:layout_widthPercent="60%"
16 app:layout_heightPercent="60%"
18 app:layout_marginStartPercent="20%"
19 app:layout_marginEndPercent="20%"
21 app:layout_marginTopPercent="10%"
22 app:layout_marginBottomPercent="10%"
24 android:background="#f5a61e"/>
26 </android.support.percent.PercentFrameLayout>
8.线性百分比布局
把PercentLinearLayout.java加入到源码中：
1 package com.example.tt.percent;
3 import android.content.Context;
4 import android.content.res.TypedArray;
5 import android.support.percent.PercentLayoutHelper;
6 import android.util.AttributeSet;
7 import android.view.ViewGroup;
8 import android.widget.LinearLayout;
10 public class PercentLinearLayout extends LinearLayout
11 {
13 private PercentLayoutHelper mPercentLayoutHelper;
15 public PercentLinearLayout(Context context, AttributeSet attrs)
16 {
17 super(context, attrs);
19 mPercentLayoutHelper = new PercentLayoutHelper(this);
20 }
23 @Override
24 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
25 {
26 mPercentLayoutHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
27 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
28 if (mPercentLayoutHelper.handleMeasuredStateTooSmall())
29 {
30 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
31 }
32 }
34 @Override
35 protected void onLayout(boolean changed, int l, int t, int r, int b)
36 {
37 super.onLayout(changed, l, t, r, b);
38 mPercentLayoutHelper.restoreOriginalParams();
39 }
41 @Override
42 public LayoutParams generateLayoutParams(AttributeSet attrs)
43 {
44 return new LayoutParams(getContext(), attrs);
45 }
48 public static class LayoutParams extends LinearLayout.LayoutParams
49 implements PercentLayoutHelper.PercentLayoutParams
50 {
51 private PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;
53 public LayoutParams(Context c, AttributeSet attrs)
54 {
55 super(c, attrs);
56 mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
57 }
59 @Override
60 public PercentLayoutHelper.PercentLayoutInfo getPercentLayoutInfo()
61 {
62 return mPercentLayoutInfo;
63 }
65 @Override
66 protected void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr)
67 {
68 PercentLayoutHelper.fetchWidthAndHeight(this, a, widthAttr, heightAttr);
69 }
71 public LayoutParams(int width, int height) {
72 super(width, height);
73 }
76 public LayoutParams(ViewGroup.LayoutParams source) {
77 super(source);
78 }
80 public LayoutParams(MarginLayoutParams source) {
81 super(source);
82 }
84 }
使用相对布局时注意：android:layout_width和height要为0dp。光指定 app:layout_heightPercent 不行。
1 <?xml version="1.0" encoding="utf-8"?>
2 <com.example.tt.percent.PercentLinearLayout
3 xmlns:android="http://schemas.android.com/apk/res/android"
4 xmlns:app="http://schemas.android.com/apk/res-auto"
5 android:layout_width="match_parent"
6 android:layout_height="match_parent"
7 android:orientation="vertical">
8 <View
9 android:layout_width="0dp"
10 android:layout_height="0dp"
11 android:background="#ff44aacc"
12 app:layout_heightPercent="10%"
13 app:layout_widthPercent="60%"/>
15 <View
16 android:layout_width="0dp"
17 android:layout_height="0dp"
18 android:background="#ff4400cc"
19 app:layout_heightPercent="10%"
20 app:layout_widthPercent="70%"/>
22 </com.example.tt.percent.PercentLinearLayout>
9.复合使用百分比布局
1 <?xml version="1.0" encoding="utf-8"?>
3 <android.support.percent.PercentRelativeLayout
4 xmlns:android="http://schemas.android.com/apk/res/android"
5 xmlns:app="http://schemas.android.com/apk/res-auto"
6 android:layout_width="match_parent"
7 android:layout_height="match_parent"
8 android:background="@color/colorParentLayout">
11 <com.example.tt.percent.PercentLinearLayout
12 android:orientation="horizontal"
13 android:id="@+id/percentLinearLayout"
14 app:layout_widthPercent="98%"
15 app:layout_heightPercent="30%"
16 app:layout_marginStartPercent="1%"
17 app:layout_marginEndPercent="1%"
18 app:layout_marginTopPercent="1%"
19 app:layout_marginBottomPercent="1%"
20 android:background="@color/colorChildLayout"
23 <ImageButton
24 android:id="@+id/imageButton"
25 android:layout_width="0dp"
26 android:layout_height="0dp"
27 android:contentDescription="w=45%,h=94%"
28 app:layout_widthPercent="45%"
29 app:layout_heightPercent="94%"
30 app:layout_marginStartPercent="2%"
31 app:layout_marginEndPercent="2%"
32 app:layout_marginTopPercent="3%"
33 app:layout_marginBottomPercent="3%"
34 android:background="#efdd82"
35 app:srcCompat="@android:drawable/ic_notification_overlay" />
37 <ImageView
38 android:id="@+id/imageView"
39 android:layout_width="0dp"
40 android:layout_height="0dp"
41 android:background="#7819d2"
42 app:layout_widthPercent="45%"
43 app:layout_heightPercent="94%"
44 app:layout_marginStartPercent="2%"
45 app:layout_marginEndPercent="2%"
46 app:layout_marginTopPercent="3%"
47 app:layout_marginBottomPercent="3%"
48 android:contentDescription="w=45%,h=94%"
50 app:srcCompat="@drawable/qq" />
52 </com.example.tt.percent.PercentLinearLayout>
54 <android.support.percent.PercentRelativeLayout
55 android:layout_below="@+id/percentLinearLayout"
56 app:layout_widthPercent="98%"
57 app:layout_heightPercent="25%"
58 android:background="@color/colorChildLayout"
59 app:layout_marginStartPercent="1%"
60 app:layout_marginEndPercent="1%"
61 app:layout_marginTopPercent="1%"
62 app:layout_marginBottomPercent="1%"
65 <com.example.tt.percent.PercentLinearLayout
66 android:id="@+id/lineLayout"
67 app:layout_widthPercent="46%"
68 app:layout_heightPercent="100%"
69 app:layout_marginStartPercent="2%"
70 app:layout_marginTopPercent="3%"
71 app:layout_marginBottomPercent="3%"
72 android:background="#7d6a5e"
73 android:orientation="vertical">
75 <TextView
76 android:layout_width="0dp"
77 android:layout_height="0dp"
78 android:background="#ff44aacc"
79 android:text="w=78.923%,h=43%"
80 app:layout_heightPercent="43%"
81 app:layout_widthPercent="78.923%"
82 app:layout_marginStartPercent="3%"
83 app:layout_marginTopPercent="3%"
84 app:layout_marginBottomPercent="3%"/>
86 <TextView
87 android:layout_width="0dp"
88 android:layout_height="0dp"
89 android:background="#ff4400cc"
90 android:text="w=89.99%,h=43%"
91 app:layout_heightPercent="43%"
92 app:layout_widthPercent="89.99%"
93 app:layout_marginStartPercent="3%"
94 app:layout_marginTopPercent="3%"
95 app:layout_marginBottomPercent="3%"/>
97 </com.example.tt.percent.PercentLinearLayout>
99 <android.support.percent.PercentFrameLayout
100 android:layout_toRightOf="@+id/lineLayout"
101 app:layout_widthPercent="46%"
102 app:layout_heightPercent="100%"
103 android:background="#9f8ea7"
104 app:layout_marginStartPercent="2%"
105 app:layout_marginTopPercent="3%"
106 app:layout_marginBottomPercent="3%"
108 android:id="@+id/percentFrameLayout">
110 <TextView
111 android:id="@+id/textView"
112 android:background="#f5a61e"
113 android:text="w=90%,h=60%\nbottom=3%,top=3%\nstart=3%,end=3%"
114 app:layout_heightPercent="60%"
115 app:layout_widthPercent="90%"
116 app:layout_marginStartPercent="3%"
117 app:layout_marginEndPercent="3%"
118 app:layout_marginTopPercent="3%"
119 app:layout_marginBottomPercent="3%"
120 />
122 </android.support.percent.PercentFrameLayout>
123 </android.support.percent.PercentRelativeLayout>
125 <android.support.percent.PercentFrameLayout
126 app:layout_widthPercent="100%"
127 app:layout_heightPercent="40%"
128 app:layout_marginStartPercent="1%"
129 app:layout_marginEndPercent="1%"
131 app:layout_marginTopPercent="60%"
132 app:layout_marginBottomPercent="1%"
133 android:background="@color/colorChildLayout"
136 <ImageView
137 android:id="@+id/mapView"
139 android:contentDescription="w=48%,h=98%"
140 android:background="#555555"
141 android:layout_alignParentBottom="true"
143 app:layout_widthPercent="98%"
144 app:layout_heightPercent="48%"
146 app:layout_marginStartPercent="1%"
147 app:layout_marginEndPercent="1%"
149 app:layout_marginTopPercent="5%"
150 app:layout_marginBottomPercent="1%"
152 app:srcCompat="@drawable/google" />
154 <Button
155 android:id="@+id/btn_bottom"
156 app:layout_widthPercent="98%"
157 app:layout_heightPercent="40%"
159 app:layout_marginStartPercent="1%"
160 app:layout_marginEndPercent="1%"
162 app:layout_marginTopPercent="55%"
163 app:layout_marginBottomPercent="1%"
164 android:textAlignment="center"
165 android:textAllCaps="false"
166 android:text="Button:w=98%,h=40%" />
168 </android.support.percent.PercentFrameLayout>
171 </android.support.percent.PercentRelativeLayout>
10.下载示例
https://git.oschina.net/xi/PercentLayout.git
