一.概述
对于一个联网的Android应用, 首页广告无限轮播基本已经成为标配了.
那么它是怎么实现的呢?
有几种实现方式呢?
二.无限轮播的实现
1.最常规的手段是用 ViewPager来实现
2.比较原始的手段是: Gallery 画廊来实现
3.最简单的实现手段是: Android image slider第三方库
下面由简到难依次实现
第三方库 Android image slider
github:https://github.com/daimajia/AndroidImageSlider/
只看图片就发现,非常绚丽, 有很多轮播方式可以选择,并且指示器图标也有很多选择方式, DIY 非常自由化.
步骤一:如果用AS开发需引入下面的库:
dependencies {
compile "com.android.support:support-v4:+"
compile 'com.squareup.picasso:picasso:2.3.2'
compile 'com.nineoldandroids:library:2.4.0'
compile 'com.daimajia.slider:library:1.1.5@aar'
}
步骤二:添加权限:
<!-- if you want to load images from the internet -->
<uses-permission android:name="android.permission.INTERNET" /> <!-- if you want to load images from a file OR from the internet -->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
步骤三: xml 的写法
Add the Slider to your layout:<com.daimajia.slider.library.SliderLayout
android:id="@+id/slider"
android:layout_width="match_parent"
android:layout_height="200dp"
/>
There are some default indicators. If you want to use a provided indicator:<com.daimajia.slider.library.Indicators.PagerIndicator
android:id="@+id/custom_indicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
/>
最后奉上代码:
package com.daimajia.slider.demo;import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;import com.daimajia.slider.library.Animations.DescriptionAnimation;
import com.daimajia.slider.library.Indicators.PagerIndicator;
import com.daimajia.slider.library.SliderLayout;
import com.daimajia.slider.library.SliderTypes.BaseSliderView;
import com.daimajia.slider.library.SliderTypes.TextSliderView;
import com.daimajia.slider.library.Tricks.ViewPagerEx;import java.util.HashMap;public class MainActivity extends ActionBarActivity implements BaseSliderView.OnSliderClickListener, ViewPagerEx.OnPageChangeListener{ private SliderLayout mDemoSlider; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDemoSlider = (SliderLayout)findViewById(R.id.slider); HashMap<String,String> url_maps = new HashMap<String, String>();
url_maps.put("Hannibal", "http://static2.hypable.com/wp-content/uploads/2013/12/hannibal-season-2-release-date.jpg");
url_maps.put("Big Bang Theory", "http://tvfiles.alphacoders.com/100/hdclearart-10.png");
url_maps.put("House of Cards", "http://cdn3.nflximg.net/images/3093/2043093.jpg");
url_maps.put("Game of Thrones", "http://images.boomsbeat.com/data/images/full/19640/game-of-thrones-season-4-jpg.jpg"); HashMap<String,Integer> file_maps = new HashMap<String, Integer>();
file_maps.put("Hannibal",R.drawable.hannibal);
file_maps.put("Big Bang Theory",R.drawable.bigbang);
file_maps.put("House of Cards",R.drawable.house);
file_maps.put("Game of Thrones", R.drawable.game_of_thrones); for(String name : file_maps.keySet()){
TextSliderView textSliderView = new TextSliderView(this);
// initialize a SliderLayout
textSliderView
.description(name)
.image(file_maps.get(name))
.setScaleType(BaseSliderView.ScaleType.Fit)
.setOnSliderClickListener(this); //add your extra information
textSliderView.bundle(new Bundle());
textSliderView.getBundle()
.putString("extra",name); mDemoSlider.addSlider(textSliderView);
}
mDemoSlider.setPresetTransformer(SliderLayout.Transformer.Accordion);
mDemoSlider.setPresetIndicator(SliderLayout.PresetIndicators.Center_Bottom);
mDemoSlider.setCustomAnimation(new DescriptionAnimation());
mDemoSlider.setDuration(4000);
mDemoSlider.addOnPageChangeListener(this);
ListView l = (ListView)findViewById(R.id.transformers);
l.setAdapter(new TransformerAdapter(this));
l.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mDemoSlider.setPresetTransformer(((TextView) view).getText().toString());
Toast.makeText(MainActivity.this, ((TextView) view).getText().toString(), Toast.LENGTH_SHORT).show();
}
}); } @Override
protected void onStop() {
// To prevent a memory leak on rotation, make sure to call stopAutoCycle() on the slider before activity or fragment is destroyed
mDemoSlider.stopAutoCycle();
super.onStop();
} @Override
public void onSliderClick(BaseSliderView slider) {
Toast.makeText(this,slider.getBundle().get("extra") + "",Toast.LENGTH_SHORT).show();
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.main,menu);
return super.onCreateOptionsMenu(menu);
} @Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.action_custom_indicator:
mDemoSlider.setCustomIndicator((PagerIndicator) findViewById(R.id.custom_indicator));
break;
case R.id.action_custom_child_animation:
mDemoSlider.setCustomAnimation(new ChildAnimationExample());
break;
case R.id.action_restore_default:
mDemoSlider.setPresetIndicator(SliderLayout.PresetIndicators.Center_Bottom);
mDemoSlider.setCustomAnimation(new DescriptionAnimation());
break;
case R.id.action_github:
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://github.com/daimajia/AndroidImageSlider"));
startActivity(browserIntent);
break;
}
return super.onOptionsItemSelected(item);
} @Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {} @Override
public void onPageSelected(int position) {
Log.d("Slider Demo", "Page Changed: " + position);
} @Override
public void onPageScrollStateChanged(int state) {}
}
注意一点: 如果 图片不带标题, 可以使用DefaultSliderView , 如果图片有标题 就用TextSliderView
分割线——————————————————————————————————-
方式2: 使用Gallery 画廊来实现图片无限轮播
