ZoomControls控件是一个可以缩放但控件，效果如下图
以下是它但一些主要但方法
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
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/layout1"
>
<ImageView
android:id="@+id/imgview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/yuanyuan"
/>
<ZoomControls
android:id="@+id/zoomcontrol"
android:layout_gravity="bottom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
ZoomExampleActivity.java
package com.loulijun.zoomcontroltest;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ZoomControls;
public class ZoomExampleActivity extends Activity {
private LinearLayout layout1;
private ZoomControls zoom;
private ImageView img;
private int id=0;
private int displayWidth;
private int displayHeight;
private float scaleWidth = 1;
private float scaleHeight = 1;
private Bitmap bmp;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
layout1 = (LinearLayout)findViewById(R.id.layout1);
//取得屏幕分辨率大小
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
displayWidth = dm.widthPixels;
//屏幕高度减去zoomControls的高度
displayHeight = dm.heightPixels;
bmp = BitmapFactory.decodeResource(getResources(), R.drawable.yuanyuan);
img = (ImageView)findViewById(R.id.imgview);
//zoom.hide();隐藏zoomControls
//zoom.show();显示zoomCOntrols
zoom = (ZoomControls)findViewById(R.id.zoomcontrol);
img = (ImageView)findViewById(R.id.imgview);
zoom.setIsZoomInEnabled(true);
zoom.setIsZoomOutEnabled(true);
//图片放大
zoom.setOnZoomInClickListener(new OnClickListener()
{
public void onClick(View v)
{
int bmpWidth = bmp.getWidth();
int bmpHeight = bmp.getHeight();
//设置图片放大但比例
double scale = 1.25;
//计算这次要放大的比例
scaleWidth = (float)(scaleWidth*scale);
scaleHeight = (float)(scaleHeight*scale);
//产生新的大小但Bitmap对象
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp = Bitmap.createBitmap(bmp,0,0,bmpWidth,bmpHeight,matrix,true);
img.setImageBitmap(resizeBmp);
}
});
//图片减小
zoom.setOnZoomOutClickListener(new OnClickListener()
{
public void onClick(View v) {
int bmpWidth = bmp.getWidth();
int bmpHeight = bmp.getHeight();
//设置图片放大但比例
double scale = 0.8;
//计算这次要放大的比例
scaleWidth = (float)(scaleWidth*scale);
scaleHeight = (float)(scaleHeight*scale);
//产生新的大小但Bitmap对象
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizeBmp = Bitmap.createBitmap(bmp,0,0,bmpWidth,bmpHeight,matrix,true);
img.setImageBitmap(resizeBmp);
}
});
}
}
效果如下：
