MainActivity

package com.bwie.a20181024_b;

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 {

private ViewPager vp_img;
private Button btn_in;
private List<Integer> imageIds;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //1.找控制元件
    vp_img = findViewById(R.id.vp_img);
    btn_in = findViewById(R.id.btn_in);
    //2.建立圖片的集合
    imageIds = new ArrayList<>();
    //3把圖片新增進去
    imageIds.add(R.drawable.t);
    imageIds.add(R.drawable.u);
    imageIds.add(R.drawable.w);
    //4建立sharedPreferences
    SharedPreferences sharedPreferences = getSharedPreferences("1606B",MODE_PRIVATE);
    if (!sharedPreferences.getBoolean("login",true)){
        startActivity(new Intent(MainActivity.this,ShowActivity.class));
        finish();
        return;
    }

    //5建立介面卡
    vp_img.setAdapter(new PagerAdapter() {
        @Override
        public int getCount() {
            return imageIds.size();
        }

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

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

        @Override
        public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
            container.removeView((View) object);
        }
    });
    //6頁面滑動
    vp_img.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int i, float v, int i1) {

        }

        @Override
        public void onPageSelected(int i) {
            if (i == imageIds.size()-1){
                //把按鈕設定成可見的
                btn_in.setVisibility(View.VISIBLE);
            }else {
                //吧按鈕設定成隱藏的
                btn_in.setVisibility(View.GONE);
            }
        }

        @Override
        public void onPageScrollStateChanged(int i) {

        }
    });

    //按鈕的點選事件
    btn_in.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(MainActivity.this,ShowActivity.class));
            finish();
            return;
        }
    });


}
 

}

佈局

<android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/vp_img"></android.support.v4.view.ViewPager>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:gravity="center_horizontal">
    <Button
        android:layout_width="wrap_content"
        android:id="@+id/btn_in"
        android:text="進入"
        android:layout_height="wrap_content"
        android:visibility="gone"/>
</LinearLayout>