Improve AutoSize#getMetricsOnMiui

Author: JessYanCoding

autosize/src/main/java/me/jessyan/autosize/AutoSize.java

@@ -24,7 +24,6 @@
 import android.util.DisplayMetrics;
 import android.view.View;
 
-import java.lang.reflect.Field;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -300,11 +299,9 @@ private static void setDensity(DisplayMetrics displayMetrics, float density, int
      * @return {@link DisplayMetrics}, 可能为 {@code null}
      */
     private static DisplayMetrics getMetricsOnMiui(Resources resources) {
-        if ("MiuiResources".equals(resources.getClass().getSimpleName()) || "XResources".equals(resources.getClass().getSimpleName())) {
+        if (AutoSizeConfig.getInstance().isMiui() && AutoSizeConfig.getInstance().getTmpMetricsField() != null) {
             try {
-                Field field = Resources.class.getDeclaredField("mTmpMetrics");
-                field.setAccessible(true);
-                return (DisplayMetrics) field.get(resources);
+                return (DisplayMetrics) AutoSizeConfig.getInstance().getTmpMetricsField().get(resources);
             } catch (Exception e) {
                 return null;
             }

autosize/src/main/java/me/jessyan/autosize/AutoSizeCompat.java

@@ -19,7 +19,6 @@
 import android.content.res.Resources;
 import android.util.DisplayMetrics;
 
-import java.lang.reflect.Field;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -280,11 +279,9 @@ private static void setDensity(DisplayMetrics displayMetrics, float density, int
      * @return {@link DisplayMetrics}, 可能为 {@code null}
      */
     private static DisplayMetrics getMetricsOnMiui(Resources resources) {
-        if ("MiuiResources".equals(resources.getClass().getSimpleName()) || "XResources".equals(resources.getClass().getSimpleName())) {
+        if (AutoSizeConfig.getInstance().isMiui() && AutoSizeConfig.getInstance().getTmpMetricsField() != null) {
             try {
-                Field field = Resources.class.getDeclaredField("mTmpMetrics");
-                field.setAccessible(true);
-                return (DisplayMetrics) field.get(resources);
+                return (DisplayMetrics) AutoSizeConfig.getInstance().getTmpMetricsField().get(resources);
             } catch (Exception e) {
                 return null;
             }

autosize/src/main/java/me/jessyan/autosize/AutoSizeConfig.java

@@ -26,6 +26,8 @@
 import android.support.v4.app.Fragment;
 import android.util.DisplayMetrics;
 
+import java.lang.reflect.Field;
+
 import me.jessyan.autosize.external.ExternalAdaptManager;
 import me.jessyan.autosize.unit.UnitsManager;
 import me.jessyan.autosize.utils.LogUtils;
@@ -124,6 +126,14 @@ public final class AutoSizeConfig {
      * 如果为 {@code false}, 则会跟随系统设置中字体大小的改变, 默认为 {@code false}
      */
     private boolean isExcludeFontScale;
+    /**
+     * 是否是 Miui 系统
+     */
+    private boolean isMiui;
+    /**
+     * Miui系统中的 mTmpMetrics 字段
+     */
+    private Field mTmpMetricsField;
     /**
      * 屏幕适配监听器，用于监听屏幕适配时的一些事件
      */
@@ -219,6 +229,15 @@ public void onLowMemory() {
         LogUtils.d("initDensity = " + mInitDensity + ", initScaledDensity = " + mInitScaledDensity);
         mActivityLifecycleCallbacks = new ActivityLifecycleCallbacksImpl(strategy == null ? new WrapperAutoAdaptStrategy(new DefaultAutoAdaptStrategy()) : strategy);
         application.registerActivityLifecycleCallbacks(mActivityLifecycleCallbacks);
+        if ("MiuiResources".equals(application.getResources().getClass().getSimpleName()) || "XResources".equals(application.getResources().getClass().getSimpleName())) {
+            isMiui = true;
+            try {
+                mTmpMetricsField = Resources.class.getDeclaredField("mTmpMetrics");
+                mTmpMetricsField.setAccessible(true);
+            } catch (Exception e) {
+                mTmpMetricsField = null;
+            }
+        }
         return this;
     }
 
@@ -462,6 +481,24 @@ public boolean isVertical() {
         return isVertical;
     }
 
+    /**
+     * 返回 {@link #isMiui}
+     *
+     * @return {@link #isMiui}
+     */
+    public boolean isMiui() {
+        return isMiui;
+    }
+
+    /**
+     * 返回 {@link #mTmpMetricsField}
+     *
+     * @return {@link #mTmpMetricsField}
+     */
+    public Field getTmpMetricsField() {
+        return mTmpMetricsField;
+    }
+
     /**
      * 设置屏幕方向
      *