android 商城 实战项目 android 实战项目app

本篇实现效果图：

新建分别一个空的Activity，命名为SplashActivity和GuideActivity(GuideActivity是app 引导页，效果下一步实现~):

1. SplashActivity.class

package com.example.myapp.activity;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.widget.LinearLayout;

import com.example.myapp.R;

public class SplashActivity extends AppCompatActivity {
    
    private LinearLayout ll;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        ll = findViewById(R.id.main_ll);
        //设置渐变效果
        setAlphaAnimation();
    }

    /**
     * 设置渐变效果
     */
    private void setAlphaAnimation() {
        //生成动画对象
        AlphaAnimation animation = new AlphaAnimation(0.3f, 1.0f);
        //设置持续时间3s
        animation.setDuration(3000);
        //给控件设置动画
        ll.setAnimation(animation);
        //设置动画监听
        animation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                jump2Activity();
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });
    }

    /**
     * 根据首次启动应用与否跳转到相应界面
     */
    private void jump2Activity() {
        SharedPreferences sharedPreferences = getSharedPreferences("data", MODE_PRIVATE);
        String First = sharedPreferences.getString("isFirst", "0");
        Intent intent = new Intent();
        if ("0".equals(First)) {
            intent.setClass(this, GuideActivity.class);
        }else{
            intent.setClass(this, MainActivity.class);
        }
        startActivity(intent);
        finish();
    }

}

2. activity_splash

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <LinearLayout
        android:id="@+id/main_ll"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:gravity="center">

        <ImageView
            android:id="@+id/main_iv"
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:src="@mipmap/ic_launcher" />

        <TextView
            android:id="@+id/main_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:layout_marginTop="10dp"
            android:text="我是splsh页" />
    </LinearLayout>


</RelativeLayout>