关于ViewPager
使用方法：先在xml中定义
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">
<android.support.v4.view.ViewPager
android:background="@drawable/img5"
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
再到Activity中写
package cn.euraxluo.myapplication;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.support.v7.app.AppCompatActivity;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.util.Log;
import android.view.*;
import android.widget.ImageView;
import cn.euraxluo.myapplication.transform.ZoomOutPageTransformer;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private ViewPager mViewPager;//viewpager
private textViewAdapter mViewAdapter;
private pictureViewAdapter mpViewAdapter;//图片的adapter
private int[] mImage = new int[10];
private View view1, view2, view3;
private List<View> viewList = new ArrayList<View>(3);//view数组
private LayoutInflater inflater;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
Log.d(TAG, "initView");
mViewPager = (ViewPager) findViewById(R.id.view_pager);
//关于图片的
// initmImage();
// mpViewAdapter = new pictureViewAdapter(mImage);
// mViewPager.setAdapter(mpViewAdapter);
//页面滑动
initmlayouts();
mViewAdapter = new textViewAdapter();
mViewPager.setAdapter(mViewAdapter);
mViewPager.setPageTransformer(true, new ZoomOutPageTransformer());//这一句是特效
}
private void initmImage() {
mImage[0] = R.drawable.img1;
mImage[1] = R.drawable.img2;
mImage[2] = R.drawable.img3;
mImage[3] = R.drawable.img4;
mImage[4] = R.drawable.img5;
mImage[5] = R.drawable.img6;
}
private void initmlayouts() {
//findViewById是找具体的widget控件
inflater = getLayoutInflater();//寻找xml下的布局文件，并且实例化
view1 = (View) inflater.inflate(R.layout.activity_music, null);//这是三个layout
view2 = (View) inflater.inflate(R.layout.activity_list, null);//实际用的时候发生了OOM
view3 = (View) inflater.inflate(R.layout.activity_about, null);
viewList.add(view1);
viewList.add(view2);
viewList.add(view3);
}
public class pictureViewAdapter extends PagerAdapter {
private int[] mImage;
public pictureViewAdapter(int[] mImage) {
this.mImage = mImage;//接受传入的mImge
}
@NonNull
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
ImageView imageView = new ImageView(container.getContext());
imageView.setImageResource(mImage[position]);//设置图片
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
container.removeView((View) object);
}
@Override
public int getCount() {//在viewpager显示几个页面
return mImage.length;
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
return view == o;
}
}
public class textViewAdapter extends PagerAdapter {
@Override
public int getCount() {
return viewList.size();//在viewPager中显示3个页面
}
@NonNull
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
container.addView(viewList.get(position));//添加到viewPager容器中
return viewList.get(position);//返回填充的对象
//1.将当前视图添加到container中，2.返回当前View
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
return view == o;
}
public void destroyItem(ViewGroup container, int position, Object obj) {
container.removeView((View) obj);//从当前container删除指定位置的view
}
}
}
一些简单的特效
package cn.euraxluo.myapplication.transform;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.View;
//扇子变换
public class RotateDownTransformer implements ViewPager.PageTransformer {
private static final float ROT_MAX = 20.0f;
private float mRot;
public void transformPage(View view, float position)
{
Log.e("TAG", view + " , " + position + "");
if (position < -1)
{ // [-Infinity,-1)
// This page is way off-screen to the left.
view.setRotation(0);
} else if (position <= 1) // a页滑动至b页 ； a页从 0.0 ~ -1 ；b页从1 ~ 0.0
{ // [-1,1]
// Modify the default slide transition to shrink the page as well
if (position < 0)
{
mRot = (ROT_MAX * position);
view.setPivotX(view.getMeasuredWidth() * 0.5f);
view.setPivotY(view.getMeasuredHeight());
view.setRotation( mRot);
} else
{
mRot = (ROT_MAX * position);
view.setPivotX(view.getMeasuredWidth() * 0.5f);
view.setPivotY(view.getMeasuredHeight());
view.setRotation( mRot);
}
// Scale the page down (between MIN_SCALE and 1)
// Fade the page relative to its size.
} else
{ // (1,+Infinity]
// This page is way off-screen to the right.
view.setRotation( 0);
}
}
}
package cn.euraxluo.myapplication.transform;/* MyApplication2
* cn.euraxluo.myapplication.Transform
* ScalePageTransformer
* 2019/5/18 16:31
* author:Euraxluo
* TODO
*/
import android.support.annotation.NonNull;
import android.support.v4.view.ViewPager;
import android.view.View;
public class ScalePageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE=0.75f;
@Override
public void transformPage(@NonNull View page, float position) {
if(position<-1.0f) {
page.setScaleX(MIN_SCALE);
page.setScaleY(MIN_SCALE);
}
// slide left
else if(position<=0.0f) {
page.setAlpha(1.0f);
page.setTranslationX(0.0f);
page.setScaleX(1.0f);
page.setScaleY(1.0f);
}
// slide right
else if(position<=1.0f) {
page.setAlpha(1.0f-position);
page.setTranslationX(-page.getWidth()*position);
float scale=MIN_SCALE+(1.0f-MIN_SCALE)*(1.0f-position);
page.setScaleX(scale);
page.setScaleY(scale);
}
// out of right screen
else {
page.setScaleX(MIN_SCALE);
page.setScaleY(MIN_SCALE);
}
}
}
package cn.euraxluo.myapplication.transform;/* MyApplication2
* cn.euraxluo.myapplication.Transform
* ZoomOutPageTransformer
* 2019/5/18 17:06
* author:Euraxluo
* TODO
*/
import android.annotation.SuppressLint;
import android.support.v4.view.ViewPager;
import android.view.View;
public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.85f;
private static final float MIN_ALPHA = 0.85f;
@SuppressLint("NewApi")
public void transformPage(View view, float position) {
if (position <= 1) //a页滑动至b页 ； a页从 0.0 -1 ；b页从1 ~ 0.0
{// 还可以修改默认的幻灯片转换以缩小页面
float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
if (position < 0) {//代表左边的view
view.setAlpha(1);
} else {// 使页面相对于大小淡入颜色。
view.setAlpha(MIN_ALPHA + (scaleFactor - MIN_SCALE)
/ (2 - MIN_SCALE) * (2 - MIN_ALPHA));
}
}
}
}
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