ZoomControls放大缩小图片

hasFocus()：判断焦点

hide()：隐藏

onTouchEvent(MotionEvent event)：现这个方法来处理触摸屏移动事件

setIsZoomInEnabled(boolean isEnabled)：是否允许放大

setIsZoomOutEnabled(boolean isEnabled)：是否允许缩小

setOnZoomInClickListener(View.OnClickListener listener)：注册放大监听器

setOnZoomOutClickListener(View.OnClickListener listener)：注册缩小监听器

setZoomSpeed(long speed)：设置缩放速度

show()：显示

这里面，如果将setIsZoomInEnabled()方法设置为false，那么这个放大的按钮就变成了灰色，不能用了，其实这个控件就是两个按钮而已，只是有外观，没有功能，如果你要放大图片或者缩小图片，还是要在监听事件中实现

开始看代码

main.xml

01	<?xmlversion="1.0"encoding="utf-8"?>

02	<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"

03	android:orientation="vertical"

04	android:layout_width="fill_parent"

05	android:layout_height="fill_parent"

06	android:id="@+id/layout1"

07

>

08	<ImageView

09	android:id="@+id/imgview"

10	android:layout_width="wrap_content"

11	android:layout_height="wrap_content"

12	android:src="@drawable/yuanyuan"

13

/>

14

15	<ZoomControls

16	android:id="@+id/zoomcontrol"

17	android:layout_gravity="bottom"

18	android:layout_width="wrap_content"

19	android:layout_height="wrap_content"

20

/>

21	</LinearLayout>

ZoomExampleActivity.java

01	packagecom.loulijun.zoomcontroltest;

02

03	importandroid.app.Activity;

04	importandroid.graphics.Bitmap;

05	importandroid.graphics.BitmapFactory;

06	importandroid.graphics.Matrix;

07	importandroid.os.Bundle;

08	importandroid.util.DisplayMetrics;

09	importandroid.view.View;

10	importandroid.view.View.OnClickListener;

11	importandroid.widget.ImageView;

12	importandroid.widget.LinearLayout;

13	importandroid.widget.ZoomControls;

14

15	publicclassZoomExampleActivity extendsActivity {

16	privateLinearLayout layout1;

17	privateZoomControls zoom;

18	privateImageView img;

19	privateintid=0;

20	privateintdisplayWidth;

21	privateintdisplayHeight;

22	privatefloatscaleWidth = 1;

23	privatefloatscaleHeight = 1;

24	privateBitmap bmp;

25

@Override

26	publicvoidonCreate(Bundle savedInstanceState) {

27	super.onCreate(savedInstanceState);

28	setContentView(R.layout.main);

29

30	layout1 = (LinearLayout)findViewById(R.id.layout1);

31	//取得屏幕分辨率大小

32	DisplayMetrics dm = newDisplayMetrics();

33	getWindowManager().getDefaultDisplay().getMetrics(dm);

34	displayWidth = dm.widthPixels;

35	//屏幕高度减去zoomControls的高度

36	displayHeight = dm.heightPixels;

37	bmp = BitmapFactory.decodeResource(getResources(), R.drawable.yuanyuan);

38	img = (ImageView)findViewById(R.id.imgview);

39	//zoom.hide();隐藏zoomControls

40	//zoom.show();显示zoomCOntrols

41

42	zoom = (ZoomControls)findViewById(R.id.zoomcontrol);

43	img = (ImageView)findViewById(R.id.imgview);

44	zoom.setIsZoomInEnabled(true);

45	zoom.setIsZoomOutEnabled(true);

46

//图片放大

47	zoom.setOnZoomInClickListener(newOnClickListener()

48

{

49	publicvoidonClick(View v)

50

{

51	intbmpWidth = bmp.getWidth();

52	intbmpHeight = bmp.getHeight();

53	//设置图片放大但比例

54	doublescale = 1.25;

55	//计算这次要放大的比例

56	scaleWidth = (float)(scaleWidth*scale);

57	scaleHeight = (float)(scaleHeight*scale);

58	//产生新的大小但Bitmap对象

59	Matrix matrix = newMatrix();

60	matrix.postScale(scaleWidth, scaleHeight);

61	Bitmap resizeBmp =

62	Bitmap.createBitmap(bmp,0,0,bmpWidth,bmpHeight,matrix,true);

63	img.setImageBitmap(resizeBmp);

64

65

}

66

});

67

//图片减小

68	zoom.setOnZoomOutClickListener(newOnClickListener()

69

{

70

71	publicvoidonClick(View v) {

72	intbmpWidth = bmp.getWidth();

73	intbmpHeight = bmp.getHeight();

74	//设置图片放大但比例

75	doublescale = 0.8;

76	//计算这次要放大的比例

77	scaleWidth = (float)(scaleWidth*scale);

78	scaleHeight = (float)(scaleHeight*scale);

79	//产生新的大小但Bitmap对象

80	Matrix matrix = newMatrix();

81	matrix.postScale(scaleWidth, scaleHeight);

82	Bitmap resizeBmp =

83	Bitmap.createBitmap(bmp,0,0,bmpWidth,bmpHeight,matrix,true);

84	img.setImageBitmap(resizeBmp);

85

}

86

87

});

88

}

89

}

效果如下：




转自： http://www.iteye.com/topic/1112742

Android