[Android] ViewStack演示

本文演示一个在同一个Activity中切换显示不同View的例子。先创建一个ViewStackActivity类，负责管理并缓存View。贴代码为上：

public abstract class ViewStackActivity extends Activity {AbstractMap<Integer, View> views = new HashMap<Integer, View>();/** * @see android.app.Activity#onCreate(Bundle) */@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);this.loadViews(this.getViewIds());}void loadViews(int[] ids){LayoutInflater flater = this.getLayoutInflater();for (int i=0; i<ids.length; ++i) {View view = flater.inflate(ids[i], null);this.OnViewCreated(ids[i], view);views.put(new Integer(ids[i]), view);}}public abstract int[] getViewIds();public abstract void OnViewCreated(int id, View view);void loadView(int id){View view = this.getLayoutInflater().inflate(id, null);this.OnViewCreated(id, view);views.put(new Integer(id), view);}void setActiveView(int id){View view = views.get(new Integer(id));if (view == null) {Toast.makeText(this, "View id: " + id + " not found.", Toast.LENGTH_SHORT).show();return;}this.setContentView(view);}} 

ViewStackActivity类有两个抽象函数getViewIds和OnViewCreated需要其子类实现。前者用于获取view id数组，后者用于首次实例化View时做些初始化工作。实际使用例子：

public class MainActivity extends ViewStackActivity { /** Called when the activity is first created. */@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);this.setActiveView(R.layout.viewstack1);}@Overridepublic int[] getViewIds() {return new int[] { R.layout.viewstack1, R.layout.viewstack2};}@Overridepublic void OnViewCreated(int id, View view) {if (id == R.layout.viewstack1) {Button btn1 = (Button) view.findViewById(R.id.Button01);btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { Toast.makeText(getBaseContext(), "Click Button02 to switch to another view...", Toast.LENGTH_SHORT).show(); }});Button btn2 = (Button) view.findViewById(R.id.Button02);btn2.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { setActiveView(R.layout.viewstack2); }});}else if (id == R.layout.viewstack2) {Button btn1 = (Button) view.findViewById(R.id.Button01);btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { setActiveView(R.layout.viewstack1); }});}}} 

资源id定义见下载包。

小结：本文给出一个用于View切换的ViewStackActivity类，根据论坛中的一个帖子的需求而作。View的组织方式千变万化，把View集中在一个Activity中可能不是好的选择，尤其是切换的View间相关性不高时简单的堆砌在一起将增加日后维护的复杂度。

 

附下载包：ViewStackEx.7z