Android代码优化----Application节点的模板写法及UI工具类

一、 MyApplication类的编写：

新建一个类MyApplication，继承自Application。代码如下：

MyApplication.java:

 package com.smyhvae.homepicdemo;

 import android.app.Application;
 import android.os.Handler;
 import android.os.Looper;

 /**
  * Created by smyhvae on 2015/5/13.
  */
 public class MyApplication extends Application {
     //获取到主线程的上下文
     private static MyApplication mContext = null;
     //获取到主线程的handler
     private static Handler mMainThreadHandler = null;
     //获取到主线程的looper
     private static Looper mMainThreadLooper = null;
     //获取到主线程
     private static Thread mMainThead = null;
     //获取到主线程的id
     private static int mMainTheadId;

     @Override
     public void onCreate() {
         // TODO Auto-generated method stub
         super.onCreate();
         this.mContext = this;
         this.mMainThreadHandler = new Handler();
         this.mMainThreadLooper = getMainLooper();
         this.mMainThead = Thread.currentThread();
         //android.os.Process.myUid()   获取到用户id
         //android.os.Process.myPid()获取到进程id
         //android.os.Process.myTid()获取到调用线程的id
         this.mMainTheadId = android.os.Process.myTid();
     }

     public static MyApplication getApplication() {
         return mContext;
     }

     public static Handler getMainThreadHandler() {
         return mMainThreadHandler;
     }

     public static Looper getMainThreadLooper() {
         return mMainThreadLooper;
     }

     public static Thread getMainThread() {
         return mMainThead;
     }

     public static int getMainThreadId() {
         return mMainTheadId;
     }

 }

上面的所有代码每次在开发一个新的app时都需要用到的，然后具体到不同的项目，再继续添加不同的东西。

然后记得在清单文件中进行声明：

     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme"
        android:name=".MyApplication">

需要声明的是上方代码的第6行android:name的属性。

二、UI工具类的编写：

这个工具类也是在app开发中经常用到的。可以直接copy。代码如下：

UIUtils.java:

 package com.smyhvae.homepicdemo.utils;

 import android.content.Context;
 import android.content.Intent;
 import android.content.res.ColorStateList;
 import android.content.res.Resources;
 import android.graphics.drawable.Drawable;
 import android.os.Handler;
 import android.view.LayoutInflater;
 import android.view.View;

 import com.smyhvae.homepicdemo.MyApplication;

 /**
  * Created by smyhvae on 2015/5/13.
  */

 public class UIUtils {

     public static Context getContext() {
         return MyApplication.getApplication();
     }

     public static Thread getMainThread() {
         return MyApplication.getMainThread();
     }

     public static long getMainThreadId() {
         return MyApplication.getMainThreadId();
     }

     /** dip转换px */
     public static int dip2px(int dip) {
         final float scale = getContext().getResources().getDisplayMetrics().density;
         return (int) (dip * scale + 0.5f);
     }

     /** pxz转换dip */
     public static int px2dip(int px) {
         final float scale = getContext().getResources().getDisplayMetrics().density;
         return (int) (px / scale + 0.5f);
     }

     /** 获取主线程的handler */
     public static Handler getHandler() {
         return MyApplication.getMainThreadHandler();
     }

     /** 延时在主线程执行runnable */
     public static boolean postDelayed(Runnable runnable, long delayMillis) {
         return getHandler().postDelayed(runnable, delayMillis);
     }

     /** 在主线程执行runnable */
     public static boolean post(Runnable runnable) {
         return getHandler().post(runnable);
     }

     /** 从主线程looper里面移除runnable */
     public static void removeCallbacks(Runnable runnable) {
         getHandler().removeCallbacks(runnable);
     }

     public static View inflate(int resId){
         return LayoutInflater.from(getContext()).inflate(resId,null);
     }

     /** 获取资源 */
     public static Resources getResources() {

         return getContext().getResources();
     }

     /** 获取文字 */
     public static String getString(int resId) {
         return getResources().getString(resId);
     }

     /** 获取文字数组 */
     public static String[] getStringArray(int resId) {
         return getResources().getStringArray(resId);
     }

     /** 获取dimen */
     public static int getDimens(int resId) {
         return getResources().getDimensionPixelSize(resId);
     }

     /** 获取drawable */
     public static Drawable getDrawable(int resId) {
         return getResources().getDrawable(resId);
     }

     /** 获取颜色 */
     public static int getColor(int resId) {
         return getResources().getColor(resId);
     }

     /** 获取颜色选择器 */
     public static ColorStateList getColorStateList(int resId) {
         return getResources().getColorStateList(resId);
     }
     //判断当前的线程是不是在主线程
     public static boolean isRunInMainThread() {
         return android.os.Process.myTid() == getMainThreadId();
     }

     public static void runInMainThread(Runnable runnable) {
         if (isRunInMainThread()) {
             runnable.run();
         } else {
             post(runnable);
         }
     }

     public static void startActivity(Intent intent){
 //        BaseActivity activity = BaseActivity.getForegroundActivity();
 //        if(activity != null){
 //            activity.startActivity(intent);
 //        }else{
 //            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 //            getContext().startActivity(intent);
 //        }
     }

     /** 对toast的简易封装。线程安全，可以在非UI线程调用。 */
     public static void showToastSafe(final int resId) {
         showToastSafe(getString(resId));
     }

     /** 对toast的简易封装。线程安全，可以在非UI线程调用。 */
     public static void showToastSafe(final String str) {
         if (isRunInMainThread()) {
             showToast(str);
         } else {
             post(new Runnable() {
                 @Override
                 public void run() {
                     showToast(str);
                 }
             });
         }
     }

     private static void showToast(String str) {
 //        BaseActivity frontActivity = BaseActivity.getForegroundActivity();
 //        if (frontActivity != null) {
 //            Toast.makeText(frontActivity, str, Toast.LENGTH_LONG).show();
 //        }
     }
 }