图片查看程序,基本缩放,滚动查看功能都是行的。
核心代码：
package snowfox.android;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.ImageView;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
private ImageView v1;
private int widthOrg, heightOrg, w;
float scale = 1;
float scaleWidth, scaleHeight;
Bitmap OrgMap, newMap;
BitmapDrawable bmd;
Matrix matrix = new Matrix();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
v1 = (ImageView)findViewById(R.id.image01);
OrgMap = BitmapFactory.decodeResource(getResources(), R.drawable.test);
widthOrg = OrgMap.getWidth();
heightOrg = OrgMap.getHeight();
//确定图片初始缩放比例,一般以适应屏幕宽度为准
w = 320;
scale = (float)w/widthOrg;
matrix = new Matrix();
matrix.postScale(scale, scale);
newMap = Bitmap.createBitmap(OrgMap, 0, 0, widthOrg, heightOrg, matrix, true);
bmd = new BitmapDrawable(newMap);
v1.setImageDrawable(bmd);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
//放大图片
if(keyCode == KeyEvent.KEYCODE_VOLUME_UP)
{
//设置放大尺寸,若大于2倍,则停止放大,另外,小于1200是为了防止因图片太大造成内存泄露
if(scale < 2.0 && w < 1200)
{
scale += 0.1;
matrix.reset(); //重置矩阵
matrix.postScale(scale, scale); //设置矩阵属性
//重新绘图
newMap = Bitmap.createBitmap(OrgMap, 0, 0, widthOrg, heightOrg, matrix, true);
//转化为drawable图像，使其可以显示在imageview中
bmd = new BitmapDrawable(newMap);
v1.setImageDrawable(bmd);
w = newMap.getWidth();
int h = newMap.getHeight();
Log.i("ta==========", w + " " +h);
}
return true;
}
//缩小图片
if(keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)
{
//设置缩放尺寸,若小于0.1倍,则停止缩小
if(scale > 0.1)
{
scale -= 0.05;
matrix.reset(); //重置矩阵
matrix.postScale(scale, scale); //设置矩阵属性
//重新绘图
newMap = Bitmap.createBitmap(OrgMap, 0, 0, widthOrg, heightOrg, matrix, true);
//转化为drawable图像，使其可以显示在imageview中
bmd = new BitmapDrawable(newMap);
v1.setImageDrawable(bmd);
w = newMap.getWidth();
int h = newMap.getHeight();
Log.i("ta==========", w + " " +h);
}
return true;
}
else
return super.onKeyDown(keyCode, event); //在其他情况下才调用super是为了屏蔽音量按键原来的功能,同时保证其他按键原功能可用
}
}
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:fillViewport="true">
<HorizontalScrollView
android:layout_width = "fill_parent"
android:layout_height = "fill_parent"
android:fillViewport = "true">
<LinearLayout
android:gravity ="center"
android:orientation="horizontal"
android:layout_width="fill_parent" android:layout_height="fill_parent">
<ImageView
android:id = "@+id/image01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType ="fitCenter"/>
</LinearLayout>
</HorizontalScrollView>
</ScrollView>
