查看寻呼机，上一个和下一个项目的尺寸更小，无限滚动

时间：2023-10-04

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跟版网的小编来一起学习吧！

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跟版网！

上一篇：Android 2.2 + ViewPager和Fragments实现TabHost使用教程 下一篇：ViewPager Activity 通知特定事件的 Fragment

查看寻呼机，上一个和下一个项目的尺寸更小，无限滚动

问题描述

UPDATE - 如果你想使当前页面缩放使用下面 PageTransformer

UPDATE - if you want to make current page zoom use below PageTransformer

相关文章

UPDATE - 如果你想使当前页面缩放使用下面 `PageTransformer`

UPDATE - if you want to make current page zoom use below `PageTransformer`