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  • 如何创建启动界面Splash Screen

    启动界面Splash Screen在应用程序是很常用的,往往在启动界面中显示产品Logo、公司Logo或者开发者信息,如果应用程序启动时间比较长,那么启动界面就是一个很好的东西,可以让用户耐心等待这段枯燥的时间。

    Android 应用程序创建一个启动界面Splash Screen非常简单。比如创建一个工程MySample,主Acitity就叫MySample,创建另一个Activity叫 SplashScreen,用于显示启动界面,资源文件为splash.xml。

    SplashScreen的代码如下:
    package com.ctoof.android;

    import android.app.Activity;
    import android.content.Intent;
    import android.os.Bundle;
    import android.view.MotionEvent;

    public class SplashScreen extends Activity {
        protected boolean _active = true;
        protected int _splashTime = 5000;
        
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.splash);
            
            Thread splashTread = new Thread() {
                @Override
                public void run() {
                    try {
                        int waited = 0;
                        while(_active && (waited < _splashTime)) {
                            sleep(100);
                            if(_active) {
                                waited += 100;
                            }
                        }
                    } catch(InterruptedException e) {
                        // do nothing
                    } finally {
                        finish();
                        // 启动主应用
                        startActivity(new Intent("com.ctoof.android.MySample.MyApp"));
                        stop();
                    }
                }
            };
            splashTread.start();
        }
        
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_DOWN) {
                _active = false;
            }
            return true;
        }
    }
    然后在AndroidMainfest.xml中修改代码如下:
    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.ctoof.android"
          android:versionCode="1"
          android:versionName="1.0">
        <application android:icon="@drawable/icon" android:label="@string/app_name">
            <activity android:name=".SplashScreen"
                      android:label="@string/app_name">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
            <activity android:name=".MyApp">
                <intent-filter>
                    <action android:name=" com.ctoof.android. MySample.MyApp " />
                    <category android:name="android.intent.category.DEFAULT" />
                </intent-filter>
            </activity>
        </application>
        <uses-sdk android:minSdkVersion="4" />
    </manifest>

    在这里负责注册两个活动。把负责管理启动界面Splash Screen的活动Activity作为应用程序的主活动,然后在SplashScreen中负责启动MyApp。

     

    new Handler().postDelayed(new Runnable(){   // 为了减少代码使用匿名Handler创建一个延时的调用
                public void run() {  
                    Intent i = new Intent(SplashScreen.this, Main.class);    //通过Intent打开最终真正的主界面Main这个Activity
                    SplashScreen.this.startActivity(i);    //启动Main界面
                    SplashScreen.this.finish();    //关闭自己这个开场屏
                }  
            }, 5000);   //5秒,够用了吧

     

    在Activity中的onCreate方法中,初始化并开始Timer:
    1    timer = new Timer(true);
    2    startTime = System.currentTimeMillis();
    3    timer.schedule(task, 0, 1);
    startTime是开始时间,要判断时间差是否满足设定的时间。下面是TimerTask的代码:
    01    private final TimerTask task = new TimerTask() {
    02                    @Override
    03                    public void run() {
    04                           if (task.scheduledExecutionTime() - startTime == 1000 || !_active) {
    05                                             Message message = new Message();  
    06                                             message.what = 0;
    07                                             timerHandler.sendMessage(message);
    08                                             timer.cancel();
    09                                             this.cancel();
    10                                          }
    11    
    12                    }
    13            };
    还有handler的代码:
    01    private final Handler timerHandler = new Handler() {
    02                    public void handleMessage(Message msg) {
    03                            switch (msg.what) {  
    04                case 0:
    05                 
    06                        SplashScreen.this.finish();
    07                            //start new activity here
    08                        break;
    09                            }  
    10                            super.handleMessage(msg);  
    11                    }
    12            };

    1    @Override
    2        public boolean onTouchEvent(MotionEvent event) {
    3            if (event.getAction() == MotionEvent.ACTION_DOWN) {
    4                _touched = false;
    5            }
    6            return true;
    7        }

    在显示Splash Screen的过程中,如果触摸了屏幕,会直接跳过Splash Screen的,给用户以更高的体验。

    这样一个基本的Splash就实现了。

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  • 原文地址:https://www.cnblogs.com/jiezzy/p/2492166.html
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