Android ImageView 放大缩小 [英] Android ImageView Zoom-in and Zoom-Out
本文介绍了Android ImageView 放大缩小的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想放大和缩小 Android ImageView.我尝试了大部分示例,但在所有示例中,ImageView 中的图像本身正在放大和缩小,而我想放大和缩小 ImageView.我想在放大时增加 ImageView 的宽度和高度,并在缩小时减少 ImageView 的宽度和高度.我如何做到这一点?
I want to Zoom-in and Zoom-out an Android ImageView. I tried most of the samples but in all of them the image in the ImageView itself is getting Zoomed-in and Zoomed-out, while I want to Zoom-in and Zoom-out the ImageView. I want to increase the ImageView width and height while Zooming-in and reduce the ImageView width and height while Zooming-out. How do I achieve that?
推荐答案
制作两个java类
缩放类
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
public class Zoom extends View {
private Drawable image;
ImageButton img,img1;
private int zoomControler=20;
public Zoom(Context context){
super(context);
image=context.getResources().getDrawable(R.drawable.j);
//image=context.getResources().getDrawable(R.drawable.icon);
setFocusable(true);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//here u can control the width and height of the images........ this line is very important
image.setBounds((getWidth()/2)-zoomControler, (getHeight()/2)-zoomControler, (getWidth()/2)+zoomControler, (getHeight()/2)+zoomControler);
image.draw(canvas);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode==KeyEvent.KEYCODE_DPAD_UP){
// zoom in
zoomControler+=10;
}
if(keyCode==KeyEvent.KEYCODE_DPAD_DOWN){
// zoom out
zoomControler-=10;
}
if(zoomControler<10){
zoomControler=10;
}
invalidate();
return true;
}
}
做二等奖
import android.app.Activity;
import android.os.Bundle;
public class Zoomexample extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(new Zoom(this));
}
}
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