Android開發(fā)學習筆記：Gallery和GridView淺析.doc

Android開發(fā)學習筆記：Gallery和GridView淺析2011-08-23 22:15:00標簽：GridView移動開發(fā)Android休閑淺析原創(chuàng)作品，允許轉載，轉載時請務必以超鏈接形式標明文章原始出處、作者信息和本聲明。否則將追究法律責任。/3061169/647355一.Gallery的簡介 Gallery（畫廊）是一個鎖定中心條目并且擁有水平滾動列表的視圖，一般用來瀏覽圖片，并且可以響應事件顯示信息。Gallery還可以和ImageSwitcher組件結合使用來實現一個通過縮略圖來瀏覽圖片的效果。Gallery常用的XML屬性屬性名稱描述android:animationDuration設置布局變化時動畫的轉換所需的時間（毫秒級）。僅在動畫開始時計時。該值必須是整數，比如：100。android:gravity指定在對象的X和Y軸上如何放置內容。指定一下常量中的一個或多個（使用 “|”分割）ConstantValueDescriptiontop0x30緊靠容器頂端，不改變其大小bottom0x50緊靠容器底部，不改變其大小left0x03緊靠容器左側，不改變其大小right0x05緊靠容器右側，不改變其大小center_vertical0x10垂直居中，不改變其大小fill_vertical0x70垂直方向上拉伸至充滿容器center_horizontal0x01水平居中，不改變其大小Fill_horizontal0x07水平方向上拉伸使其充滿容器center0x11居中對齊，不改變其大小fill0x77在水平和垂直方向上拉伸，使其充滿容器clip_vertical0x80垂直剪切（當對象邊緣超出容器的時候，將上下邊緣超出的部分剪切掉）clip_horizontal0x08水平剪切（當對象邊緣超出容器的時候，將左右邊緣超出的部分剪切掉）android:spacing圖片之間的間距android:unselectedAlpha設置未選中的條目的透明度(Alpha)。該值必須是float類型，比如：“1.2”。首先介紹Gallery單獨使用的例子：MainActivity.javapackagecom.android.gallerydemo; importandroid.app.Activity; importandroid.content.Context; importandroid.os.Bundle; importandroid.view.View; importandroid.view.ViewGroup; importandroid.widget.AdapterView; importandroid.widget.AdapterView.OnItemClickListener; importandroid.widget.BaseAdapter; importandroid.widget.Gallery; importandroid.widget.ImageView; importandroid.widget.Toast; publicclassMainActivityextendsActivity privateGallerygallery; OverridepublicvoidonCreate(BundlesavedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.main); gallery=(Gallery)findViewById(R.id.gallery); /設置圖片適配器 gallery.setAdapter(newImageAdapter(this); /設置監(jiān)聽器 gallery.setOnItemClickListener(newOnItemClickListener() OverridepublicvoidonItemClick(AdapterViewparent,Viewv,intposition,longid) Toast.makeText(MainActivity.this,點擊了第+(position+1)+張圖片,Toast.LENGTH_LONG).show(); ); classImageAdapterextendsBaseAdapter /聲明Context privateContextcontext; /圖片源數組 privateIntegerimageInteger= R.drawable.pic1, R.drawable.pic2, R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6, R.drawable.pic7 ; /聲明ImageAdapter publicImageAdapter(Contextc) context=c; Override/獲取圖片的個數 publicintgetCount() returnimageInteger.length; Override/獲取圖片在庫中的位置 publicObjectgetItem(intposition) returnposition; Override/獲取圖片在庫中的位置 publiclonggetItemId(intposition) /TODOAuto-generatedmethodstub returnposition; OverridepublicViewgetView(intposition,ViewconvertView,ViewGroupparent) ImageViewimageView=newImageView(context); /給ImageView設置資源 imageView.setImageResource(imageIntegerposition); /設置比例類型 imageView.setScaleType(ImageView.ScaleType.FIT_XY); /設置布局圖片128x192顯示 imageView.setLayoutParams(newGallery.LayoutParams(128,192); returnimageView; main.xml效果圖：Gallery和ImageSwitcher組件結合使用的例子：MainActivity.javapackagecom.android.gallerytest; importandroid.app.Activity; importandroid.content.Context; importandroid.os.Bundle; importandroid.view.View; importandroid.view.ViewGroup; importandroid.view.Window; importandroid.view.animation.AnimationUtils; importandroid.widget.AdapterView; importandroid.widget.BaseAdapter; importandroid.widget.Gallery; importandroid.widget.ImageSwitcher; importandroid.widget.ImageView; importandroid.widget.AdapterView.OnItemSelectedListener; importandroid.widget.Gallery.LayoutParams; importandroid.widget.ViewSwitcher.ViewFactory; publicclassMainActivityextendsActivityimplementsOnItemSelectedListener, ViewFactory privateImageSwitchermSwitcher; /大圖片對應的縮略圖源數組 privateIntegermThumbIds=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; /大圖片源數組 privateIntegermImageIds=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; OverridepublicvoidonCreate(BundlesavedInstanceState) super.onCreate(savedInstanceState); /設置窗口無標題 requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.main); mSwitcher=(ImageSwitcher)findViewById(R.id.switcher); /注意在使用一個ImageSwitcher之前， /一定要調用setFactory方法，要不setImageResource這個方法會報空指針異常。 mSwitcher.setFactory(this); /設置動畫效果 mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in); mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out); Galleryg=(Gallery)findViewById(R.id.gallery); /添加OnItemSelectedListener監(jiān)聽器 g.setAdapter(newImageAdapter(this); g.setOnItemSelectedListener(this); /創(chuàng)建內部類ImageAdapter publicclassImageAdapterextendsBaseAdapter publicImageAdapter(Contextc) mContext=c; publicintgetCount() returnmThumbIds.length; publicObjectgetItem(intposition) returnposition; publiclonggetItemId(intposition) returnposition; publicViewgetView(intposition,ViewconvertView,ViewGroupparent) ImageViewi=newImageView(mContext); i.setImageResource(mThumbIdsposition); /設置邊界對齊 i.setAdjustViewBounds(true); /設置布局參數 i.setLayoutParams(newGallery.LayoutParams( LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT); /設置背景資源 i.setBackgroundResource(R.drawable.picture_frame); returni; privateContextmContext; Override/實現onItemSelected()方法，更換圖片 publicvoidonItemSelected(AdapterViewadapter,Viewv,intposition, longid) /設置圖片資源 mSwitcher.setImageResource(mImageIdsposition); OverridepublicvoidonNothingSelected(AdapterViewarg0) Override/實現makeView()方法，為ImageView設置布局格式 publicViewmakeView() ImageViewi=newImageView(this); /設置背景顏色 i.setBackgroundColor(0xFF000000); /設置比例類型 i.setScaleType(ImageView.ScaleType.FIT_CENTER); /設置布局參數 i.setLayoutParams(newImageSwitcher.LayoutParams( LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT); returni; main.xml 效果圖:二.GridView的簡介 GridView(網格視圖)是按照行列的方式來顯示內容的，一般用于顯示圖片，圖片等內容，比如實現九宮格圖，用GridView是首選，也是最簡單的。主要用于設置Adapter。GridView常用的XML屬性：屬性名稱描述android:columnWidth設置列的寬度。android:gravity設置此組件中的內容在組件中的位置?？蛇x的值有：top、bottom、left、right、center_vertical、fill_vertical、center_horizontal、fill_horizontal、center、fill、clip_vertical可以多選，用“|”分開。android:horizontalSpacing兩列之間的間距。android:numColumns設置列數。android:stretchMode縮放模式。android:verticalSpacing兩行之間的間距。下面有三個例子，第一個是只顯示圖片的，第二個是顯示圖片文字的(這里的圖片是Android系統自帶的圖片)，第三個是顯示自定義的圖片文字。前面兩個例子的實現都不是很難，第三個例子的實現有些復雜，學習GridView的時候，就想著能不能自定義自己喜歡的圖片加上文字，在網上找些資料，一般都是第二個例子的形式的，最后在視頻學習上找到了能實現自定義自己的圖片的例子。自己就照著例子去學習，修改成了第三個例子。第一個例子：MainActivity.javapackage com.android.gridview.activity; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity Override public void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.main); GridView gv = (GridView)findViewById(R.id.GridView1); /為GridView設置適配器 gv.setAdapter(new MyAdapter(this); /注冊監(jiān)聽事件 gv.setOnItemClickListener(new OnItemClickListener() public void onItemClick(AdapterView parent, View v, int position, long id) Toast.makeText(MainActivity.this, pic + position, Toast.LENGTH_SHORT).show(); ); /自定義適配器 class MyAdapter extends BaseAdapter /上下文對象 private Context context; /圖片數組 private Integer imgs = R.drawable.pic0, R.drawable.pic1, R.drawable.pic2, R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6, R.drawable.pic7, R.drawable.pic8, R.drawable.pic0, R.drawable.pic1, R.drawable.pic2, R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6, R.drawable.pic7, R.drawable.pic8, ; MyAdapter(Context context) this.context = context; public int getCount() return imgs.length; public Object getItem(int item) return item; public long getItemId(int id) return id; /創(chuàng)建View方法 public View getView(int position, View convertView, ViewGroup parent) ImageView imageView; if (convertView = null) imageView = new ImageView(context); imageView.setLayoutParams(new GridView.LayoutParams(75, 75);/設置ImageView對象布局 imageView.setAdjustViewBounds(false);/設置邊界對齊 imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);/設置刻度的類型 imageView.setPadding(8, 8, 8, 8);/設置間距 else imageView = (ImageView) convertView; imageView.setImageResource(imgsposition);/為ImageView設置圖片資源 return imageView; main.xml 效果圖：第二個例子：MainActivity.javapackage com.android.gridview2.activity; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.os.Bundle; import android.widget.GridView; import android.widget.SimpleAdapter; public class MainActivity extends Activity private GridView gv; Override protected void onCreate(Bundle savedInstanceState) / TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.gridview); /準備要添加的數據條目 ListMap items = new ArrayListMap(); for (int i = 0; i 9; i+) Map item = new HashMap(); item.put(imageItem, R.drawable.icon);/添加圖像資源的ID item.put(textItem, icon + i);/按序號添加ItemText items.add(item); /實例化一個適配器 SimpleAdapter adapter = new SimpleAdapter(this, items, R.layout.grid_item, new StringimageItem, textItem, new intR.id.image_item, R.id.text_item); /獲得GridView實例 gv = (GridView)findViewById(R.id.mygridview); /為GridView設置適配器 gv.setAdapter(adapter); gridview.xml grid_item.xml 效果圖：第三個例子：MainActivity.javapackage com.android.gridview3; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import android.widget.AdapterView.OnItemClickListener; public class MainActivity extends Activity private GridView gridView; /圖片的文字標題 private String titles = new String pic1, pic2, pic3, pic4, pic5, pic6, pic7, pic8, pic9; /圖片ID數組 private int images = new int R.drawable.pic1, R.drawable.pic2, R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6, R.drawable.pic7, R.drawable.pic8,R.drawable.pic9 ; Override public void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.main); gridView = (GridView) findViewById(R.id.gridview); PictureAdapter adapter = new PictureAdapter(titles, images, this); gridView.setAdapter(adapter); gridView.setOnItemClickListener(new OnItemClickListener() public void onItemClick(AdapterView parent, View v, int position, long id) Toast.makeText(MainActivity.this, pic + (position+1), Toast.LENGTH_SHORT).show(); ); /自定義適配器 class PictureAdapter extends