Android編程滑動(dòng)效果之Gallery+GridView實(shí)現(xiàn)圖片預(yù)覽功能(附demo源碼下載)

2020-04-11 10:50:22

字體：大中小

供稿：網(wǎng)友

本文實(shí)例講述了Android編程滑動(dòng)效果之Gallery+GridView實(shí)現(xiàn)圖片預(yù)覽功能。分享給大家供大家參考，具體如下：

Android系統(tǒng)自帶一個(gè)GridView和Gallery兩個(gè)控件，GridView網(wǎng)格顯示，Gallery單個(gè)瀏覽，兩者結(jié)合起來可以真正實(shí)現(xiàn)Gallery瀏覽圖片效果。

本示例通過GridView和Gallery兩個(gè)控件，模仿實(shí)現(xiàn)一個(gè)完整的仿Gallery圖像集的圖片瀏覽效果。效果圖如下：

1、GridView

首先，自定義一個(gè)GridImageAdapter圖片適配器，用于填充GridView控件的圖片

public class GridImageAdapter extends BaseAdapter {  private Context mContext;  Drawable btnDrawable;  public GridImageAdapter(Context context) {    mContext = context;    Resources resources = context.getResources();    btnDrawable = resources.getDrawable(R.drawable.bg);  }  @Override  public int getCount() {    return ImageSource.mThumbIds.length;  }  @Override  public Object getItem(int position) {    return position;  }  @Override  public long getItemId(int position) {    return position;  }  @Override  public View getView(int position, View convertView, ViewGroup parent) {    ImageViewExt imageView;    int space;    if (convertView == null) {      imageView = new ImageViewExt(mContext);      if (imageCol == 5) {        space = dm.heightPixels / imageCol - 6;        imageView.setLayoutParams(new GridView.LayoutParams(space, space));      } else {        space = dm.widthPixels / imageCol - 6;        imageView.setLayoutParams(new GridView.LayoutParams( space, space));      }      imageView.setAdjustViewBounds(true);      imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);  // 縮放圖片使其長和寬一樣       imageView.setPadding(3, 3, 3, 3);    } else {      imageView = (ImageViewExt) convertView;    }    imageView.setImageResource(ImageSource.mThumbIds[position]);    return imageView;  }}

然后，用GridImageAdapter填充GridView

gridView = (GridView) findViewById(R.id.myGrid);gridImageAdapter = new GridImageAdapter(this);gridView.setAdapter(gridImageAdapter);gridView.setOnItemClickListener(listener); // 設(shè)置點(diǎn)擊監(jiān)聽事件

最后，設(shè)置GridView控件的點(diǎn)擊監(jiān)聽事件

AdapterView.OnItemClickListener listener = new AdapterView.OnItemClickListener() {  @Override  public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) {    Intent intent = new Intent();    intent.setClass(GridViewActivity.this, GalleryActivity.class);    intent.putExtra("position", position);    startActivity(intent);  }};

2、Gallery

完成了GridView的圖片顯示、監(jiān)聽事件后，現(xiàn)在點(diǎn)擊圖片，會(huì)啟動(dòng)一個(gè)Activity來顯示當(dāng)前點(diǎn)擊的圖片，此時(shí)顯示圖片的控件便是Gallery

首先，同GridView一樣，自定義一個(gè)ImageAdapter圖片適配器，用來填充Gallery

public class ImageAdapter extends BaseAdapter {  private Context mContext;  private int mPos;  public ImageAdapter(Context context) {    mContext = context;  }  public void setOwnposition(int ownposition) {    this.mPos = ownposition;  }  public int getOwnposition() {    return mPos;  }  @Override  public int getCount() {    return ImageSource.mThumbIds.length;  }  @Override  public Object getItem(int position) {    mPos=position;    return position;  }  @Override  public long getItemId(int position) {    mPos=position;    return position;  }  @Override  public View getView(int position, View convertView, ViewGroup parent) {    mPos=position;    ImageView imageview = new ImageView(mContext);    imageview.setBackgroundColor(0xFF000000);    imageview.setScaleType(ImageView.ScaleType.FIT_CENTER);    imageview.setLayoutParams(new myGallery.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));    imageview.setImageResource(ImageSource.mThumbIds[position]);    return imageview;  }}

然后，用ImageAdapter填充Gallery

myGallery galllery = (myGallery) findViewById(R.id.mygallery);Intent intent = getIntent();position = intent.getIntExtra("position", 0); // 獲取GridViewActivity傳來的圖片位置positionImageAdapter imgAdapter=new ImageAdapter(this);galllery.setAdapter(imgAdapter); // 設(shè)置圖片ImageAdaptergalllery.setSelection(position); // 設(shè)置當(dāng)前顯示圖片  Animation an= AnimationUtils.loadAnimation(this,R.anim.scale ); // Gallery動(dòng)畫  galllery.setAnimation(an);

此時(shí)，如果細(xì)心可以注意到，我們的Gallery也是自己定義的myGallery，具體定義如下：

public class myGallery extends Gallery {  boolean isFirst = false;  boolean isLast = false;  public myGallery(Context context) {    super(context);  }  public myGallery(Context context, AttributeSet paramAttributeSet) {    super(context, paramAttributeSet);  }  /** 是否向左滑動(dòng)（true - 向左滑動(dòng)； false - 向右滑動(dòng)） */  private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2) {    return e2.getX() > e1.getX();  }  @Override  public boolean onFling(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {    ImageAdapter ia = (ImageAdapter) this.getAdapter();    int p = ia.getOwnposition(); // 獲取當(dāng)前圖片的position    int count = ia.getCount(); // 獲取全部圖片的總數(shù)count    int kEvent;    if (isScrollingLeft(e1, e2)) {      if (p == 0 && isFirst) {        Toast.makeText(this.getContext(), "已是第一頁", Toast.LENGTH_SHORT).show();      } else if (p == 0) {        isFirst = true;      } else {        isLast = false;      }      kEvent = KeyEvent.KEYCODE_DPAD_LEFT;    } else {      if (p == count - 1 && isLast) {        Toast.makeText(this.getContext(), "已到最后一頁", Toast.LENGTH_SHORT).show();      } else if (p == count - 1) {        isLast = true;      } else {        isFirst = false;      }      kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;    }    onKeyDown(kEvent, null);    return true;  }}

GalleryActivity的布局文件gallery.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:gravity="center"  android:orientation="horizontal"  android:padding="10dip" >  <RelativeLayout    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:background="#000000"    android:padding="2dip" >    <com.homer.gridgallery.myGallery      android:id="@+id/mygallery"      android:layout_width="fill_parent"      android:layout_height="fill_parent"      android:spacing="16dp" />  </RelativeLayout></LinearLayout>

完整實(shí)例代碼點(diǎn)擊此處本站下載。

更多關(guān)于Android相關(guān)內(nèi)容感興趣的讀者可查看本站專題：《Android開發(fā)動(dòng)畫技巧匯總》、《Android開發(fā)入門與進(jìn)階教程》及《Android控件用法總結(jié)》。

希望本文所述對(duì)大家Android程序設(shè)計(jì)有所幫助。

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