Android实现新闻项目

版权声明：个人见解,希望可以帮助大家,共同进步. https://blog.csdn.net/weixin_40783315/article/details/81351965

这是一个新闻类的项目,由于工作原因只能是一点一点写,后续会补充完整,有疑惑可以私信我.

首先是首页面,欢迎页实现     旋转 缩放 渐变 的效果 ,三个引导页实现侧滑的同时底部的小点跟随侧滑移动.

GuideActivity.java

package com.example.lenovo.myx2_d1;

import android.app.Activity;
import android.content.Context;
import android.media.Image;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by LENOVO on 2018/08/01.
 */

public class GuideActivity extends Activity {

    private LinearLayout dotLayout;
    private ImageView redDot;
    private ViewPager viewPager;
    private int[] imgs = {R.drawable.guide_1, R.drawable.guide_2, R.drawable.guide_3};
    private int leftMargin =0 ;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.guide_activity);

        leftMargin = dip2px(this,10f);

        initView();
        initLoad();
        initViewPager();
    }

    private List<ImageView> imgViews = new ArrayList<>();

    private void initViewPager(){

        // 把图片int集合遍历，同时创建多个ImageView,且设置图片，然后把imgView放入到imgViews集合里

        for (int img :imgs){
            ImageView imgView = new ImageView(this);
            imgView.setBackgroundResource(img);
            imgViews.add(imgView);
        }
        MyPager myPager = new MyPager(imgViews);
        viewPager.setAdapter(myPager);
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                int tempMargin = leftMargin;
                int leftMar = (int) ((position*tempMargin)+(tempMargin*positionOffset));
                RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) redDot.getLayoutParams();
                params.leftMargin = leftMar*2;
                redDot.setLayoutParams(params);
            }

            @Override
            public void onPageSelected(int position) {

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }
    private void initView() {
        dotLayout = findViewById(R.id.dot_layout);
        redDot = findViewById(R.id.red_dot);
        viewPager = findViewById(R.id.view_pager);
    }

    private void initLoad() {

        // 添加三个点到Layout

        for (int x = 0; x < imgs.length; x++) {
            ImageView dot = new ImageView(this);
            dot.setBackgroundResource(R.drawable.point_normal);
            if (x != 0) {
                LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
                params.leftMargin = leftMargin;

                dot.setLayoutParams(params);
            }
            dotLayout.addView(dot);
        }
    }

    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    public static int dip2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}

MyPager.java

package com.example.lenovo.myx2_d1;

/**
 * Created by LENOVO on 2018/08/01.
 */

import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public  class MyPager extends PagerAdapter {

    private List<ImageView> imgList;

    public MyPager(List<ImageView> imgs){
        if (imgList==null){
            imgList  = new ArrayList<>();
            imgList.addAll(imgs);
        }
    }

    @Override
    public int getCount() {
        return imgList.size();
    }

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

    @NonNull // 添加子view==imageview，到container

    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
        ImageView img=  imgList.get(position);
        container.addView(img);
        return img;
    }

    @Override
    public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
        container.removeView(imgList.get(position));
    }
}

SplashActivity.java

package com.example.lenovo.myx2_d1;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.RotateAnimation;
import android.view.animation.ScaleAnimation;
import android.widget.RelativeLayout;

/**
 * Created by LENOVO on 2018/08/01.
 */

public class SplashActivity extends AppCompatActivity {
    private RelativeLayout rootLayout;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        initView();
        // 实现  旋转  缩放  渐变   的效果

        AlphaAnimation alphaAnimation = new AlphaAnimation(0,1);
        alphaAnimation.setFillAfter(true);

        ScaleAnimation  scaleAnimation=new ScaleAnimation(0,1,0,1,ScaleAnimation.RELATIVE_TO_SELF,0.5f,ScaleAnimation.RELATIVE_TO_SELF,0.5f);
        scaleAnimation.setFillAfter(true);

        RotateAnimation rotateAnimation=new RotateAnimation(0,360,RotateAnimation.RELATIVE_TO_SELF,0.5f,RotateAnimation.RELATIVE_TO_SELF,0.5f);
        rotateAnimation.setFillAfter(true);

        AnimationSet animationSet = new AnimationSet(false);
        animationSet.addAnimation(alphaAnimation);
        animationSet.addAnimation(scaleAnimation);
        animationSet.addAnimation(rotateAnimation);

        animationSet.setDuration(2000);
        rootLayout.startAnimation(animationSet);

        animationSet.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {

                Intent intent = new Intent(SplashActivity.this,GuideActivity.class);
                startActivity(intent);
                finish();
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });




    }

    private void initView(){
        rootLayout = findViewById(R.id.root_layout);
    }

    private void initLoad(){

    }
}

以下是布局文件

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/root_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/splash_bg_newyear">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/splash_sheep_newyear" />
</RelativeLayout>

content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    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"

    tools:context=".SplashActivity"
    tools:showIn="@layout/activity_main">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

guide_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="50dp"
        android:orientation="horizontal">

        <LinearLayout
            android:id="@+id/dot_layout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal" />

        <ImageView
            android:id="@+id/red_dot"
            android:background="@drawable/point_red"
            android:layout_width="10dp"
            android:layout_height="10dp" />
    </RelativeLayout>
</RelativeLayout>

values/style.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.lenovo.myx2_d1">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".SplashActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".GuideActivity"></activity>
    </application>


</manifest>