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本篇文章为大家展示了Android中怎么实现图片浏览,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
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首先是Android图片浏览中layout xml:
< ?xml version="1.0" encoding="utf-8"?> < RelativeLayout xmlns:android="http://schemas.Android.com/apk/res/Android" Android:layout_width="fill_parent" Android:layout_height="fill_parent"> < ImageSwitcher Android:id="@+id/switcher" Android:layout_width="fill_parent" Android:layout_height="fill_parent" Android:layout_alignParentTop="true" Android:layout_alignParentLeft="true" /> < Gallery Android:id="@+id/gallery" Android:background="#55000000" Android:layout_width="fill_parent" Android:layout_height="60dp" Android:layout_alignParentBottom="true" Android:layout_alignParentLeft="true" Android:gravity="center_vertical" Android:spacing="16dp" /> < /RelativeLayout>
layout里面用到了前面所说的两个控件,ImageSwitcher用啦显示全图,Gallery用来显示缩略图。着重看看ImageSwitcher,在ImageSwitcher1中需要实现ViewSwitcher.ViewFactory这个接口,这个接口里有个方法makeView,这样就产生了用来显示图片的view. ImageSwitcher调用过程是这样的,首先要有一个Factory为它提供一个View,然后ImageSwitcher就可以初始化各种资源了。注意在使用一个ImageSwitcher之前,一定要调用setFactory方法,要不setImageResource这个方法会报空指针异常。
下面是Android图片浏览代码:
package com.zx.imageswitcher;
import Android.app.Activity;
import Android.content.Context;
import Android.os.Bundle;
import Android.view.View;
import Android.view.ViewGroup;
import Android.view.animation.AnimationUtils;
import Android.widget.AdapterView;
import Android.widget.BaseAdapter;
import Android.widget.Gallery;
import Android.widget.ImageSwitcher;
import Android.widget.ImageView;
import Android.widget.ViewSwitcher;
import Android.widget.Gallery.LayoutParams;
public class ImageSwitcherTest extends Activity implements
AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory{
private ImageSwitcher mSwitcher;
private Integer[] mThumbIds = {
R.drawable.sample_thumb_0, R.drawable.sample_thumb_1,
R.drawable.sample_thumb_2, R.drawable.sample_thumb_3,
R.drawable.sample_thumb_4, R.drawable.sample_thumb_5,
R.drawable.sample_thumb_6, R.drawable.sample_thumb_7};
private Integer[] mImageIds = {
R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2,
R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5,
R.drawable.sample_6, R.drawable.sample_7};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
mSwitcher.setFactory(this);
mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
Android.R.anim.fade_in));
mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
Android.R.anim.fade_out));
Gallery g = (Gallery) findViewById(R.id.gallery);
g.setAdapter(new ImageAdapter(this));
g.setOnItemSelectedListener(this);
}
/*
* override for ViewSwitcher.ViewFactory#makeView()
*/
public View makeView() {
ImageView i = new ImageView(this);
i.setBackgroundColor(0xFF000000);
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
i.setLayoutParams(new ImageSwitcher.LayoutParams
(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
return i;
}
/*
* override for
* AdapterView.OnItemSelectedListener#onItemSelected()
*/
public void onItemSelected(AdapterView parent,
View v, int position, long id) {mSwitcher.setImageResource(mImageIds[position]);
}
/*
* override for AdapterView.OnItemSelectedListener
#onNothingSelected()*/
public void onNothingSelected(AdapterView< ?> arg0) {
// TODO Auto-generated method stub
}
public class ImageAdapter extends BaseAdapter {
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView,
ViewGroup parent) {ImageView i = new ImageView(mContext);
i.setImageResource(mThumbIds[position]);
i.setAdjustViewBounds(true);
i.setLayoutParams(new Gallery.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
i.setBackgroundResource(R.drawable.picture_frame);
return i;
}
private Context mContext;
}
}
从Android图片浏览的代码中看到还实现了AdapterView.OnItemSelectedListener,这样就需要重写onItemSelected()方法,然后在该方法中:mSwitcher.setImageResource(mImageIds[position]);这样就实现了图片在ImageSwitcher中的切换。
上述内容就是Android中怎么实现图片浏览,你们学到知识或技能了吗?如果还想学到更多技能或者丰富自己的知识储备,欢迎关注创新互联行业资讯频道。