一，简介：
今日头条的适配方案是启动Application ,重新定义布局参数
适配方法如下
调取方法
public class Myapplication extends Application {
@Override
public void onCreate() {
ScreenAdapter.setup(this);
ScreenAdapter.register(this , 360 , ScreenAdapter.MATCH_BASE_WIDTH , ScreenAdapter.MATCH_UNIT_DP);
super.onCreate();
}
}
创建适配类
ScreenAdapter/**
* 屏幕适配方案
* <br>
* <p>PS: 提供 dp、sp 以及 pt 作为适配单位，建议开发中以 dp、sp 适配为主，pt 可作为 dp、sp 的适配补充</p>
* <p>PS: 由今日头条适配方案修改而来: https://mp.weixin.qq.com/s/d9QCoBP6kV9VSWvVldVVwA</p>
*/
public final class ScreenAdapter {
/**
* 屏幕适配的基准
*/
public static final int MATCH_BASE_WIDTH = 0;
public static final int MATCH_BASE_HEIGHT = 1;
/**
* 适配单位
*/
public static final int MATCH_UNIT_DP = 0;
public static final int MATCH_UNIT_PT = 1;
// 适配信息
private static MatchInfo sMatchInfo;
// Activity 的生命周期监测
private static Application.ActivityLifecycleCallbacks mActivityLifecycleCallback;
private ScreenAdapter() {
throw new UnsupportedOperationException("u can't instantiate me...");
}
/**
* 初始化
*
* @param application
*/
public static void setup(@NonNull final Application application) {
DisplayMetrics displayMetrics = application.getResources().getDisplayMetrics();
if (sMatchInfo == null) {
// 记录系统的原始值
sMatchInfo = new MatchInfo();
sMatchInfo.setScreenWidth(displayMetrics.widthPixels);
sMatchInfo.setScreenHeight(displayMetrics.heightPixels);
sMatchInfo.setAppDensity(displayMetrics.density);
sMatchInfo.setAppDensityDpi(displayMetrics.densityDpi);
sMatchInfo.setAppScaledDensity(displayMetrics.scaledDensity);
sMatchInfo.setAppXdpi(displayMetrics.xdpi);
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
// 添加字体变化的监听
application.registerComponentCallbacks(new ComponentCallbacks() {
@Override
public void onConfigurationChanged(Configuration newConfig) {
// 字体改变后,将 appScaledDensity 重新赋值
if (newConfig != null && newConfig.fontScale > 0) {
sMatchInfo.setAppScaledDensity(application.getResources().getDisplayMetrics().scaledDensity);
}
}
@Override
public void onLowMemory() {
}
});
}
}
/**
* 在 application 中全局激活适配（也可单独使用 match() 方法在指定页面中配置适配）
*/
@RequiresApi(api = Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public static void register(@NonNull final Application application, final float designSize, final int matchBase, final int matchUnit) {
if (mActivityLifecycleCallback == null) {
mActivityLifecycleCallback = new Application.ActivityLifecycleCallbacks() {
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
if (activity != null) {
match(activity, designSize, matchBase, matchUnit);
}
}
@Override
public void onActivityStarted(Activity activity) {
}
@Override
public void onActivityResumed(Activity activity) {
}
@Override
public void onActivityPaused(Activity activity) {
}
@Override
public void onActivityStopped(Activity activity) {
}
@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
}
@Override
public void onActivityDestroyed(Activity activity) {
}
};
application.registerActivityLifecycleCallbacks(mActivityLifecycleCallback);
}
}
/**
* 全局取消所有的适配
*/
@RequiresApi(api = Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public static void unregister(@NonNull final Application application, @NonNull int... matchUnit) {
if (mActivityLifecycleCallback != null) {
application.unregisterActivityLifecycleCallbacks(mActivityLifecycleCallback);
mActivityLifecycleCallback = null;
}
for (int unit : matchUnit) {
cancelMatch(application, unit);
}
}
/**
* 适配屏幕（放在 Activity 的 setContentView() 之前执行）
*
* @param context
* @param designSize
*/
public static void match(@NonNull final Context context, final float designSize) {
match(context, designSize, MATCH_BASE_WIDTH, MATCH_UNIT_DP);
}
/**
* 适配屏幕（放在 Activity 的 setContentView() 之前执行）
*
* @param context
* @param designSize
* @param matchBase
*/
public static void match(@NonNull final Context context, final float designSize, int matchBase) {
match(context, designSize, matchBase, MATCH_UNIT_DP);
}
/**
* 适配屏幕（放在 Activity 的 setContentView() 之前执行）
*
* @param context
* @param designSize 设计图的尺寸
* @param matchBase 适配基准 MATCH_BASE_WIDTH或者MATCH_BASE_HEIGHT
* @param matchUnit 使用的适配单位 MATCH_UNIT_DP或者MATCH_UNIT_PT
*/
public static void match(@NonNull final Context context, final float designSize, int matchBase, int matchUnit) {
if (designSize == 0) {
throw new UnsupportedOperationException("The designSize cannot be equal to 0");
}
if (matchUnit == MATCH_UNIT_DP) {
matchByDP(context, designSize, matchBase);
} else if (matchUnit == MATCH_UNIT_PT) {
matchByPT(context, designSize, matchBase);
}
}
/**
* 重置适配信息，取消适配
*/
public static void cancelMatch(@NonNull final Context context) {
cancelMatch(context, MATCH_UNIT_DP);
cancelMatch(context, MATCH_UNIT_PT);
}
/**
* 重置适配信息，取消适配
*
* @param context
* @param matchUnit 需要取消适配的单位
*/
public static void cancelMatch(@NonNull final Context context, int matchUnit) {
if (sMatchInfo != null) {
final DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
if (matchUnit == MATCH_UNIT_DP) {
if (displayMetrics.density != sMatchInfo.getAppDensity()) {
displayMetrics.density = sMatchInfo.getAppDensity();
}
if (displayMetrics.densityDpi != sMatchInfo.getAppDensityDpi()) {
displayMetrics.densityDpi = (int) sMatchInfo.getAppDensityDpi();
}
if (displayMetrics.scaledDensity != sMatchInfo.getAppScaledDensity()) {
displayMetrics.scaledDensity = sMatchInfo.getAppScaledDensity();
}
} else if (matchUnit == MATCH_UNIT_PT) {
if (displayMetrics.xdpi != sMatchInfo.getAppXdpi()) {
displayMetrics.xdpi = sMatchInfo.getAppXdpi();
}
}
}
}
public static MatchInfo getMatchInfo() {
return sMatchInfo;
}
/**
* 使用 dp 作为适配单位（适合在新项目中使用，在老项目中使用会对原来既有的 dp 值产生影响）
* <br>
* <ul>
* dp 与 px 之间的换算:
* <li> px = density * dp </li>
* <li> density = dpi / 160 </li>
* <li> px = dp * (dpi / 160) </li>
* </ul>
*
* @param context
* @param designSize 人工设计图的宽/高（单位: dp）
* 例如：安卓UI设计成720*1280 ,屏幕5英寸， 则1dp=2px ,宽为360dp
* @param base 适配基准
*/
private static void matchByDP(@NonNull final Context context, final float designSize, int base) {
final float targetDensity;
if (base == MATCH_BASE_WIDTH) {
targetDensity = sMatchInfo.getScreenWidth() * 1f / designSize;
} else if (base == MATCH_BASE_HEIGHT) {
targetDensity = sMatchInfo.getScreenHeight() * 1f / designSize;
} else {
targetDensity = sMatchInfo.getScreenWidth() * 1f / designSize;
}
final int targetDensityDpi = (int) (targetDensity * 160);
final float targetScaledDensity = targetDensity * (sMatchInfo.getAppScaledDensity() / sMatchInfo.getAppDensity());
final DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
displayMetrics.density = targetDensity;
displayMetrics.densityDpi = targetDensityDpi;
displayMetrics.scaledDensity = targetScaledDensity;
}
/**
* 使用 pt 作为适配单位（因为 pt 比较冷门，新老项目皆适合使用；也可作为 dp 适配的补充，
* 在需要同时适配宽度和高度时，使用 pt 来适配 dp 未适配的宽度或高度）
* <br/>
* <p> pt 转 px 算法: pt * metrics.xdpi * (1.0f/72) </p>
*
* @param context
* @param designSize 设计图的宽/高（单位: pt）
* @param base 适配基准
*/
private static void matchByPT(@NonNull final Context context, final float designSize, int base) {
final float targetXdpi;
if (base == MATCH_BASE_WIDTH) {
targetXdpi = sMatchInfo.getScreenWidth() * 72f / designSize;
} else if (base == MATCH_BASE_HEIGHT) {
targetXdpi = sMatchInfo.getScreenHeight() * 72f / designSize;
} else {
targetXdpi = sMatchInfo.getScreenWidth() * 72f / designSize;
}
final DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
displayMetrics.xdpi = targetXdpi;
}
/**
* 适配信息
*/
public static class MatchInfo {
private int screenWidth;
private int screenHeight;
private float appDensity;
private float appDensityDpi;
private float appScaledDensity;
private float appXdpi;
public int getScreenWidth() {
return screenWidth;
}
public void setScreenWidth(int screenWidth) {
this.screenWidth = screenWidth;
}
public int getScreenHeight() {
return screenHeight;
}
public void setScreenHeight(int screenHeight) {
this.screenHeight = screenHeight;
}
public float getAppDensity() {
return appDensity;
}
public void setAppDensity(float appDensity) {
this.appDensity = appDensity;
}
public float getAppDensityDpi() {
return appDensityDpi;
}
public void setAppDensityDpi(float appDensityDpi) {
this.appDensityDpi = appDensityDpi;
}
public float getAppScaledDensity() {
return appScaledDensity;
}
public void setAppScaledDensity(float appScaledDensity) {
this.appScaledDensity = appScaledDensity;
}
public float getAppXdpi() {
return appXdpi;
}
public void setAppXdpi(float appXdpi) {
this.appXdpi = appXdpi;
}
}
}布局 activity_main.xml：
<?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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:orientation="vertical"
>
<RelativeLayout
android:layout_width="100dp"
android:layout_height="200dp"
android:background="@color/colorAccent"
android:layout_margin="20dp"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/app_name"
/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
<RelativeLayout
android:layout_width="100dp"
android:layout_height="200dp"
android:background="@color/colorAccent"
android:layout_margin="20dp"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/app_name"
/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
<RelativeLayout
android:layout_width="100dp"
android:layout_height="200dp"
android:background="@color/colorAccent"
android:layout_margin="20dp"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/app_name"
/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
</LinearLayout>
</RelativeLayout>适配成功后，显示如下：
