Android开发丶渐变启动页和带有指示器的引导页

package com.fantasychong.guidepagetest0905; import android.content.Intent; import android.content.SharedPreferences; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.view.ViewPager; import android.support.v4.widget.ImageViewCompat; import android.support.v7.app.AppCompatActivity; import android.view.LayoutInflater; import android.view.View; import android.widget.Adapter; import android.widget.Button; import android.widget.ImageView; import android.widget.LinearLayout; import java.util.ArrayList; import java.util.List; /* *Crated by yedona on 2018/9/5 */ public class GuideActivity extends AppCompatActivity implements View.OnClickListener, ViewPager.OnPageChangeListener { private ViewPager vp; private List<ImageView> imageViews; private int[] imgs= {R.color.colorPrimary, R.color.colorAccent, R.color.colorPrimaryDark, R.color.colorAccent}; private Button btn; private ImageView[] dotViews; private VpAdapter adapter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_guide); vp= findViewById(R.id.guide_vp); btn= findViewById(R.id.guide_btn); btn.setOnClickListener(this); //初始化图片 initImgs(); //初始化底部圆点指示器 initDots(); adapter= new VpAdapter(imageViews); vp.setAdapter(adapter); vp.addOnPageChangeListener(this); } /** * 改变首次打开的状态 */ private void setisFirst() { SharedPreferences.Editor editor= getSharedPreferences("data", MODE_PRIVATE).edit(); editor.putString("isFirst", "1"); editor.commit(); } /** * 初始化底部圆点指示器 */ private void initDots() { LinearLayout layout= findViewById(R.id.guide_ll); LinearLayout.LayoutParams params= new LinearLayout.LayoutParams(20, 20); params.setMargins(10, 0, 10, 0); dotViews= new ImageView[imgs.length]; for (int i= 0; i< imageViews.size(); i++){ ImageView imageView= new ImageView(this); imageView.setLayoutParams(params); imageView.setImageResource(R.drawable.dotselector); if (i== 0){ imageView.setSelected(true); }else{ imageView.setSelected(false); } dotViews[i]= imageView; final int finalI = i; dotViews[i].setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { vp.setCurrentItem(finalI); } }); layout.addView(imageView); } } /** * 初始化图片 */ private void initImgs() { ViewPager.LayoutParams params= new ViewPager.LayoutParams(); imageViews= new ArrayList<ImageView>(); for (int i= 0; i< imgs.length; i++){ ImageView imageView= new ImageView(this); imageView.setLayoutParams(params); imageView.setImageResource(imgs[i]); imageView.setScaleType(ImageView.ScaleType.FIT_XY); imageViews.add(imageView); } } @Override public void onClick(View view) { switch (view.getId()){ case R.id.guide_btn: setisFirst(); Intent intent= new Intent(GuideActivity.this, MainActivity.class); startActivity(intent); finish(); break; } } @Override public void onPageScrolled(int i, float v, int i1) { } @Override public void onPageSelected(int arg0) { for (int i= 0; i< dotViews.length; i++){ if (arg0== i){ dotViews[i].setSelected(true); }else { dotViews[i].setSelected(false); } if (arg0== dotViews.length- 1){ btn.setVisibility(View.VISIBLE); }else { btn.setVisibility(View.GONE); } } } @Override public void onPageScrollStateChanged(int i) { } }