Android 获取本地应用图标Icon

参考链接：Android Studio打包arr包并导入Unity中
 参考链接：Unity中调用Android方法

根据包名获取本地Icon
Android java代码

package com.android.util;

import android.app.Activity;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;

public class UseForUnity {

    /// 设置一个 Activity 参数
    private static Activity _unityActivity;

    // 通过反射获取 Unity 的 Activity 的上下文
    public static Activity getActivity() {

        if (null == _unityActivity) {
            try {
                Class<?> classtype = Class.forName("com.unity3d.player.UnityPlayer");
                Activity activity = (Activity) classtype.getDeclaredField("currentActivity").get(classtype);
                _unityActivity = activity;
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            }
        }

        return _unityActivity;
    }

    // 通过包名获取应用的 Drawable icon 并转为 byte[] 数据
    public byte[] getDrawableIconByPackageName(String packageName) {
        Drawable icon = getAppIcon(packageName);
        Bitmap bitmap = FileTool.DrawableToBitmap(icon);
        return FileTool.BitmapToByte(bitmap);
    }

    // 通过包名获取对应的 Drawable 数据
    private Drawable getAppIcon(String packageName) {
        try {
            PackageManager pm = getActivity().getPackageManager();
            ApplicationInfo info = pm.getApplicationInfo(packageName, 0);

            return info.loadIcon(pm);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
}

Unity中调用获取：

    /// <summary>
    /// 加载本地app图标
    /// </summary>
    /// <param name="packageName"></param>
    /// <returns></returns>
    public static Texture2D LoadAPPIcon(string packageName)
    {
        Texture2D texture = new Texture2D(100, 100);
#if UNITY_ANDROID
        try
        {
            // 调用aar包
            AndroidJavaObject androidJavaObject = new AndroidJavaObject("com.android.util.UseForUnity");

            // 通过安卓类的接口类获取Drawable的byte[]
            // 第一个参数：对应函数接口的名称
            // 第二个参数：对应函数接口的包名参数
            byte[] drawableBytes = androidJavaObject.Call<byte[]>("getDrawableIconByPackageName", packageName);
            texture.LoadImage(drawableBytes);
        }
        catch (System.Exception e)
        {
            Debug.LogError("加载app图标报错！！！" + packageName);
            Debug.LogError(e);
        }
#endif
        return texture;
    }

但是有时需要，显示本地所有应用的Icon，如果通过遍历本地应用，每个本地应用挨个使用上述单个获取应用Icon方法，则会有1s左右的卡顿。解决方法：Android使用线程去加载所有本地应用Icon，加载完毕，调用回调，通知Unity。

Android java代码：
回调：

package com.android.util;

//获取icon回调
public interface GetIconCallback {
    public void onSuccess(int byteLenth);

    public void onError(String errorMessage);
}

开启线程，加载图标：

package com.android.util;

import android.app.Activity;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;

public class UseForUnity {

    private byte[][] imageList;

    /// 设置一个 Activity 参数
    private static Activity _unityActivity;

    // 通过反射获取 Unity 的 Activity 的上下文
    public static Activity getActivity() {

        if (null == _unityActivity) {
            try {
                Class<?> classtype = Class.forName("com.unity3d.player.UnityPlayer");
                Activity activity = (Activity) classtype.getDeclaredField("currentActivity").get(classtype);
                _unityActivity = activity;
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            }
        }

        return _unityActivity;
    }

    //根据index获取应用图标
    public byte[] getIconByIndex(int index) {
        if (imageList == null || imageList.length <= 0) {
            // 说明此时未加载完毕
            return null;
        }
        return imageList[index];
    }

    // 开启线程，获取应用图标
    public void getIconByPackageName(final String[] packageNames, final GetIconCallback callback) {
        Thread t = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    imageList = new byte[packageNames.length][];
                    for (int i = 0; i < packageNames.length; i++) {
                        imageList[i] = getDrawableIconByPackageName(packageNames[i]);
                    }
                    // 调用回调，通知Unity加载完毕
                    callback.onSuccess(imageList.length);
                } catch (Exception e) {
                    callback.onError("get icon error");
                }
            }
        });
        t.start();
    }

    // 通过包名获取应用的 Drawable icon 并转为 byte[] 数据
    private byte[] getDrawableIconByPackageName(String packageName) {
        Drawable icon = getAppIcon(packageName);
        Bitmap bitmap = FileTool.DrawableToBitmap(icon);
        return FileTool.BitmapToByte(bitmap);
    }

    // 通过包名获取对应的 Drawable 数据
    private Drawable getAppIcon(String packageName) {
        try {
            PackageManager pm = getActivity().getPackageManager();
            ApplicationInfo info = pm.getApplicationInfo(packageName, 0);

            return info.loadIcon(pm);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
}

Unity收到onSuccess回调后，通过getIconByIndex，获得Icon：

    /// <summary>
    /// 安卓回调
    /// </summary>
    class AndroidPluginCallback : AndroidJavaProxy
    {
        public AndroidPluginCallback() : base("com.android.util.GetIconCallback") { }

        public void onSuccess(int byteLenth)
        {
            // 图标加载成功 可以获取图标
        }

        public void onError(string error)
        {
            Debug.Log("本地app icon读取失败！");
            Debug.Log(error);
        }
    }

    public static AndroidJavaObject _androidJavaObject;

    /// <summary>
    /// 开启加载应用图标线程
    /// </summary>
    /// <param name="packageName"></param>
    public static void StartLoadAppIcon(string[] packageNames)
    {
#if UNITY_ANDROID
        try
        {
            _androidJavaObject = new AndroidJavaObject("com.android.util.UseForUnity");
            _androidJavaObject.Call("getIconByPackageName", packageNames, new AndroidPluginCallback());
        }
        catch (System.Exception e)
        {
            LWDebug.LogError("开启加载应用图标线程报错！！！");
            LWDebug.LogError(e);
        }
#endif
    }

    /// <summary>
    /// 根据index加载图标
    /// </summary>
    /// <param name="index"></param>
    /// <returns></returns>
    public static Texture2D LoadIconByIndex(int index)
    {
        Texture2D texture = new Texture2D(100, 100);
#if UNITY_ANDROID
        try
        {
            // 调用getIconByIndex获取Icon，注意此处用的还需原来的androidJavaObject，不能new一个，否则获取不到
            byte[] drawableBytes = _androidJavaObject.Call<byte[]>("getIconByIndex", index);
            texture.LoadImage(drawableBytes);
        }
        catch (System.Exception e)
        {
            LWDebug.LogError("根据index加载图标!!!");
            LWDebug.LogError(e);
        }
#endif
        return texture;
    }