Android界面控件

5. this.imageLayout.addView(imageView, new LinearLayout.LayoutParams(LinearLayou

t.LayoutParams.WRAP_CONTENT,

6. LinearLayout.LayoutParams.WRAP_CONTENT)); 7. } catch (IOException e) { 8. e.printStackTrace(); 9. }

5.3.2 ImageButton

图5.3.2ImageButton

android.widget.ImageButton图片控件，继承自android.widget.ImageView，在android.widget包中。

最简单的使用方法。src设置图片路径，可引用drawable的图片。

Xml代码

1.

动态声明ImageView，设置src。

Java代码

1. 2. 3. 4. 5. 6. 7. 8. 9.

try {

ImageButton imageButton = new ImageButton(this);

InputStream inputStream = super.getAssets().open(\

imageButton.setImageDrawable(Drawable.createFromStream(inputStream, \

this.imageLayout.addView(imageButton, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,

LinearLayout.LayoutParams.WRAP_CONTENT)); } catch (IOException e) { e.printStackTrace(); }

5.3.3 ImageSwitcher和Gallery

图5.3.3 ImageSwitcher

android.widget. ImageSwitcher图片控件，继承自

android.widget.ViewSwitcher（ViewGroup）。在android.widget包中。 ImageSwithcer是用来图片显示那块区域的控件，使用方法

setInAnimation(Animation)，setOutAnimation(Animation)设置动画。 Gallery是来控制底下那个图标索引列表索引用的。ImageAdapter继承自BaseAdapter，设置Gallery的适配器。

在layout添加ImageSwitcher和Gallery。定义Activity，implements接口OnItemSelectedListener, ViewFactory。onCreate的时候定义要显示图片路径列表，设置Gallery的Adapter。onItemSelected事件触发时，设置对应的图片。

Layout文件。

Xml代码

1.

2. 5.

6. 11.

12.

16. android:layout_alignParentBottom=\ 17. android:layout_alignParentLeft=\ 18. android:gravity=\ 19. android:spacing=\ /> 20.

21.

SwitcherActivity类。

Java代码

1. public class SwitcherActivity extends Activity implements OnItemSelectedListener, View

Factory { 2.

3. private ImageSwitcher imageSwitcher; 4. private Gallery gallery; 5.

6. private ArrayList imageAssetPathList = new ArrayList(); 7.

8. @Override

9. protected void onCreate(Bundle savedInstanceState) { 10. super.onCreate(savedInstanceState);

11. super.setContentView(R.layout.switcher);

12. this.imageSwitcher = (ImageSwitcher) findViewById(R.id.switcher); 13. this.gallery = (Gallery) findViewById(R.id.gallery); 14.

15. for (int i = 1; i <= 20; i++) {

16. this.imageAssetPathList.add(\ 17. } 18.

19. this.imageSwitcher.setFactory(this);

20. this.gallery.setAdapter(new ImageAdapter(this, this.imageAssetPathList)); 21. this.gallery.setOnItemSelectedListener(this); 22. 23. } 24.

25. @Override

26. public View makeView() {

27. ImageView imageView = new ImageView(this); 28. imageView.setBackgroundColor(0xFF000000);

29. imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);

30. imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FIL

L_PARENT, LayoutParams.FILL_PARENT)); 31. return imageView; 32. } 33.

34. @Override

35. public void onItemSelected(AdapterView parent, View view, int position, long id) {

36. try {

37. InputStream inputStream = super.getAssets().open(this.imageAssetPathList.get(po

sition));

38. imageSwitcher.setImageDrawable(Drawable.createFromStream(inputStream, \

position));

39. } catch (IOException e) { 40. e.printStackTrace(); 41. } 42. } 43.

44. @Override

45. public void onNothingSelected(AdapterView parent) { 46. 47. } 48. 49. }

ImageAdapter类

Java代码

1. 2. 3. 4. 5. 6. 7. 8.

public class ImageAdapter extends BaseAdapter {

private Context content;

private ArrayList imageAssetPathList;

public ImageAdapter(Context content, ArrayList imageAssetPathList) { this.content = content;

this.imageAssetPathList = imageAssetPathList;