引导页跳转

//引导也布局




    

    

//.java
package com.example.yindao;

import android.content.Intent;
import android.content.SharedPreferences;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private ViewPager vp_splash;
    private Button btn_goto_main;
    private List imgIds;
    private SharedPreferences sp;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initView();
        initData();
        initListener();
    }

    private void initData() {
        sp = getSharedPreferences("isFirstUse", MODE_PRIVATE);
        if(sp.getBoolean("fin", false)){
            startActivity(new Intent(MainActivity.this,LoginActivityActivity.class));
            finish();
        }else{
            SharedPreferences.Editor edit = sp.edit();
            edit.putBoolean("fin", true);
            edit.commit();
        }


        imgIds = new ArrayList<>();
        imgIds.add(R.drawable.one);
        imgIds.add(R.drawable.two);
        imgIds.add(R.drawable.tree);


        vp_splash.setAdapter(new PagerAdapter() {
            @Override
            public int getCount() {
                return imgIds.size();
            }

            @Override
            public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
                return view == object;
            }

            @NonNull
            @Override
            public Object instantiateItem(@NonNull ViewGroup container, int position) {
                ImageView img = new ImageView(MainActivity.this);
                img.setImageResource(imgIds.get(position));
                container.addView(img);
                return img;
            }

            @Override
            public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
                container.removeView((View) object);
            }
        });
    }
    private void initListener() {
        vp_splash.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if (position == imgIds.size() - 1) {
                    btn_goto_main.setVisibility(View.VISIBLE);
                } else {
                    btn_goto_main.setVisibility(View.GONE);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

    private void initView() {
        vp_splash = (ViewPager) findViewById(R.id.vp_splash);
        btn_goto_main = (Button) findViewById(R.id.btn_goto_main);

        btn_goto_main.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_goto_main:
                Intent intent = new Intent(this, LoginActivityActivity.class);
                startActivity(intent);
                break;
        }
    }
}