查看寻呼机，上一个和下一个项目的尺寸更小，无限滚动 [英] View Pager with previous and next item smaller in size with infinite scroll
本文介绍了查看寻呼机，上一个和下一个项目的尺寸更小，无限滚动的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
想要创建与以下 UI 相同的视图分页器，应用了自定义转换器但无法正常工作.
ViewPager.java
public class MyViewPager extends ViewPager implements ViewPager.PageTransformer {public static final String TAG = "MyViewPager";私人浮动 MAX_SCALE = 0.0f;私人 int mPageMargin;私人布尔动画启用=真；私人布尔fadeEnabled=false；私人浮动淡入淡出=0.5f；公共 MyViewPager(上下文上下文){这(上下文，空)；}public MyViewPager(上下文上下文，AttributeSet attrs){超级(上下文，属性)；//剪裁应该在寻呼机上为其子级关闭，以便它们可以超出范围.设置剪辑儿童(假)；setClipToPadding(假);//避免在页面末尾出现淡入淡出效果setOverScrollMode(2);setPageTransformer(false, this);setOffscreenPageLimit(3);mPageMargin = dp2px(context.getResources(), 50);setPadding(mPageMargin, mPageMargin, mPageMargin, mPageMargin);}公共 int dp2px(资源资源，int dp){return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resource.getDisplayMetrics());}公共无效 setAnimationEnabled(布尔启用){this.animationEnabled = 启用；}公共无效 setFadeEnabled(boolean fadeEnabled) {this.fadeEnabled = fadeEnabled;}公共无效 setFadeFactor(浮动淡化因子){this.fadeFactor = fadeFactor;}@覆盖公共无效 setPageMargin(int marginPixels){mPageMargin = 边距像素；//setPadding(mPageMargin, mPageMargin, mPageMargin, mPageMargin);}@覆盖public void transformPage(查看页面，浮动位置) {if (mPageMargin <= 0|| !animationEnabled)返回;page.setPadding(mPageMargin/3, mPageMargin/3, mPageMargin/3, mPageMargin/3);if (MAX_SCALE == 0.0f && 位置> 0.0f && 位置< 1.0f) {MAX_SCALE = 位置；}位置 = 位置 - MAX_SCALE；浮动绝对位置 = Math.abs(位置);如果(位置 <= -1.0f || 位置 >= 1.0f){如果(淡入淡出)page.setAlpha(fadeFactor);//页面不可见 -- 停止任何正在运行的动画}否则如果(位置== 0.0f){//页面被选中 -- 如有必要，重置任何视图page.setScaleX((1 + MAX_SCALE));page.setScaleY((1 + MAX_SCALE));page.setAlpha(1);} 别的 {page.setScaleX(1 + MAX_SCALE * (1 - absolutePosition));page.setScaleY(1 + MAX_SCALE * (1 - absolutePosition));如果(淡入淡出)page.setAlpha(Math.max(fadeFactor, 1 - absolutePosition));}}} 解决方案
UPDATE - 如果你想使当前页面缩放使用下面 PageTransformer
导入android.os.Bundle；导入androidx.appcompat.app.AppCompatActivity；导入androidx.viewpager2.widget.ViewPager2；公共类 JavaActivity 扩展 AppCompatActivity {ViewPager2 我的ViewPager2；我的适配器我的适配器；@覆盖protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_java);myViewPager2 = findViewById(R.id.viewpager);我的适配器 = 新的我的适配器(这个)；myViewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);myViewPager2.setAdapter(MyAdapter);myViewPager2.setOffscreenPageLimit(3);float pageMargin = getResources().getDimensionPixelOffset(R.dimen.pageMargin);float pageOffset = getResources().getDimensionPixelOffset(R.dimen.offset);myViewPager2.setPageTransformer((页面，位置) -> {浮动 myOffset = 位置 * -(2 * pageOffset + pageMargin);如果(位置 < -1){page.setTranslationX(-myOffset);} else if (位置 <= 1) {float scaleFactor = Math.max(0.7f, 1 - Math.abs(位置 - 0.14285715f));page.setTranslationX(myOffset);page.setScaleY(scaleFactor);page.setAlpha(scaleFactor);} 别的 {page.setAlpha(0);page.setTranslationX(myOffset);}});}}输出
注意:您可以从
Want to create the view pager same as following UI, applied custom transformer but not working.
ViewPager.java
public class MyViewPager extends ViewPager implements ViewPager.PageTransformer {
public static final String TAG = "MyViewPager";
private float MAX_SCALE = 0.0f;
private int mPageMargin;
private boolean animationEnabled=true;
private boolean fadeEnabled=false;
private float fadeFactor=0.5f;
public MyViewPager(Context context) {
this(context, null);
}
public MyViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
// clipping should be off on the pager for its children so that they can scale out of bounds.
setClipChildren(false);
setClipToPadding(false);
// to avoid fade effect at the end of the page
setOverScrollMode(2);
setPageTransformer(false, this);
setOffscreenPageLimit(3);
mPageMargin = dp2px(context.getResources(), 50);
setPadding(mPageMargin, mPageMargin, mPageMargin, mPageMargin);
}
public int dp2px(Resources resource, int dp) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resource.getDisplayMetrics());
}
public void setAnimationEnabled(boolean enable) {
this.animationEnabled = enable;
}
public void setFadeEnabled(boolean fadeEnabled) {
this.fadeEnabled = fadeEnabled;
}
public void setFadeFactor(float fadeFactor) {
this.fadeFactor = fadeFactor;
}
@Override
public void setPageMargin(int marginPixels) {
mPageMargin = marginPixels;
// setPadding(mPageMargin, mPageMargin, mPageMargin, mPageMargin);
}
@Override
public void transformPage(View page, float position) {
if (mPageMargin <= 0|| !animationEnabled)
return;
page.setPadding(mPageMargin / 3, mPageMargin / 3, mPageMargin / 3, mPageMargin / 3);
if (MAX_SCALE == 0.0f && position > 0.0f && position < 1.0f) {
MAX_SCALE = position;
}
position = position - MAX_SCALE;
float absolutePosition = Math.abs(position);
if (position <= -1.0f || position >= 1.0f) {
if(fadeEnabled)
page.setAlpha(fadeFactor);
// Page is not visible -- stop any running animations
} else if (position == 0.0f) {
// Page is selected -- reset any views if necessary
page.setScaleX((1 + MAX_SCALE));
page.setScaleY((1 + MAX_SCALE));
page.setAlpha(1);
} else {
page.setScaleX(1 + MAX_SCALE * (1 - absolutePosition));
page.setScaleY(1 + MAX_SCALE * (1 - absolutePosition));
if(fadeEnabled)
page.setAlpha( Math.max(fadeFactor, 1 - absolutePosition));
}
}
}
解决方案
UPDATE - if you want to make current page zoom use below PageTransformer
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;
public class JavaActivity extends AppCompatActivity {
ViewPager2 myViewPager2;
MyAdapter MyAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_java);
myViewPager2 = findViewById(R.id.viewpager);
MyAdapter = new MyAdapter(this);
myViewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);
myViewPager2.setAdapter(MyAdapter);
myViewPager2.setOffscreenPageLimit(3);
float pageMargin = getResources().getDimensionPixelOffset(R.dimen.pageMargin);
float pageOffset = getResources().getDimensionPixelOffset(R.dimen.offset);
myViewPager2.setPageTransformer((page, position) -> {
float myOffset = position * -(2 * pageOffset + pageMargin);
if (position < -1) {
page.setTranslationX(-myOffset);
} else if (position <= 1) {
float scaleFactor = Math.max(0.7f, 1 - Math.abs(position - 0.14285715f));
page.setTranslationX(myOffset);
page.setScaleY(scaleFactor);
page.setAlpha(scaleFactor);
} else {
page.setAlpha(0);
page.setTranslationX(myOffset);
}
});
}
}
OUTPUT
NOTE: you can download complete code from my GitHub repositories
Try this way
JavaActivity
import android.os.Bundle;
import android.view.View;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.view.ViewCompat;
import androidx.viewpager2.widget.ViewPager2;
public class JavaActivity extends AppCompatActivity {
ViewPager2 myViewPager2;
MyAdapter MyAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_java);
myViewPager2 = findViewById(R.id.viewpager);
MyAdapter = new MyAdapter(this);
myViewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);
myViewPager2.setAdapter(MyAdapter);
myViewPager2.setOffscreenPageLimit(3);
float pageMargin= getResources().getDimensionPixelOffset(R.dimen.pageMargin);
float pageOffset = getResources().getDimensionPixelOffset(R.dimen.offset);
myViewPager2.setPageTransformer(new ViewPager2.PageTransformer() {
@Override
public void transformPage(@NonNull View page, float position) {
float myOffset = position * -(2 * pageOffset + pageMargin);
if (myViewPager2.getOrientation() == ViewPager2.ORIENTATION_HORIZONTAL) {
if (ViewCompat.getLayoutDirection(myViewPager2) == ViewCompat.LAYOUT_DIRECTION_RTL) {
page.setTranslationX(-myOffset);
} else {
page.setTranslationX(myOffset);
}
} else {
page.setTranslationY(myOffset);
}
}
});
}
}
activity_java layout file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".JavaActivity">
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/viewpager"
android:clipToPadding="false"
android:clipChildren="false"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
>
MyAdapter
import android.content.Context;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private Context context;
public MyAdapter(Context context) {
this.context = context;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.row_item, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
holder.tvName.setText(String.format("Row number%d", position));
if (position % 2 ==0){
holder.imgBanner.setBackgroundColor(Color.RED);
}else {
holder.imgBanner.setBackgroundColor(Color.GREEN);
}
}
@Override
public int getItemCount() {
return 15;
}
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView tvName;
ImageView imgBanner;
public MyViewHolder(@NonNull View itemView) {
super(itemView);
tvName = itemView.findViewById(R.id.tvName);
imgBanner = itemView.findViewById(R.id.imgBanner);
}
}
}
row_item layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_marginLeft="@dimen/pageMarginAndOffset"
android:layout_marginRight="@dimen/pageMarginAndOffset"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="@+id/imgBanner"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorAccent"
android:contentDescription="@string/app_name"/>
<TextView
android:id="@+id/tvName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center"
android:layout_centerInParent="true"
android:textColor="@android:color/white"
android:textSize="20sp"
android:textStyle="bold"
tools:text="Hello"/>
</RelativeLayout>
OUTPUT
这篇关于查看寻呼机，上一个和下一个项目的尺寸更小，无限滚动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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