最近作图片的显示，遇到了些问题，简单总结
1）可以用ImageSwicher和ImageView结合在来做，这样会用到setFectory（），华而不实
最要命的是如果图片的大小超过屏幕，实现比较困难，目前是没有找到方法
2）最简单的方法是用ImageView，图片直接FIT_CENTER,android会根据图片的大小自动调节
保持图片的比例。如果图片分辨率超过屏幕，android也会自动的调整到屏幕能放下整张的图片
在放大图片的时候，可以用ImageView的SetFrame（） 和setScale（）方法，可以把图片放大
到超过屏幕，原理就是ImageView放大，图片跟着放大。同时也是可以添加各种animation.
大致如下：
代码如下:
Animation animation = AnimationUtils.loadAnimation(Main.this, R.anim.my_scale_action);
imageView.setLayoutParams(new Gallery.LayoutParams(206, 206));
imageView.startAnimation(animation);
写一个自己的MyImageView类，代码如下，可以直接用
代码如下:
package com.practice.imageviewpic;
import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
//创建一个自己的ImageView类
class MyImageView extends ImageView {
private float scale = 0.1f;
//两点触屏后之间的长度
private float beforeLenght;
private float afterLenght;
//单点移动的前后坐标值
private float afterX,afterY;
private float beforeX,beforeY;
public MyImageView(Context context) {
super(context);
}
public MyImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
//用来设置ImageView的位置
private void setLocation(int x,int y) {
this.setFrame(this.getLeft()+x, this.getTop()+y, this.getRight()+x, this.getBottom()+y);
}
public void setScale(float temp,int flag) {
if(flag==0) {
this.setFrame(this.getLeft()-(int)(temp*this.getWidth()),
this.getTop()-(int)(temp*this.getHeight()),
this.getRight()+(int)(temp*this.getWidth()),
this.getBottom()+(int)(temp*this.getHeight()));
}else {
&nbs
p; this.setFrame(this.getLeft()+(int)(temp*this.getWidth()),
this.getTop()+(int)(temp*this.getHeight()),
this.getRight()-(int)(temp*this.getWidth()),
this.getBottom()-(int)(temp*this.getHeight()));
}
}
//绘制边框
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Rect rec=canvas.getClipBounds();
rec.left++;
rec.top++;
rec.bottom--;
rec.right--;
Paint paint=new Paint();
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
canvas.drawRect(rec, paint);
}
public void moveWithFinger(MotionEvent event) {
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
//Log.d(TAG, "down ..");
beforeX = event.getX();
beforeY = event.getY();
break;
case MotionEvent.ACTION_MOVE:
//Log.d(TAG, "move ..");
afterX = event.getX();
&nbs
p; afterY = event.getY();
this.setLocation((int)(afterX-beforeX),(int)(afterY-beforeY));
beforeX = afterX;
beforeY = afterY;
break;
case MotionEvent.ACTION_UP:
//Log.d(TAG, "up ..");
break;
}
}
public void scaleWithFinger(MotionEvent event) {
float moveX = event.getX(1) - event.getX(0);
float moveY = event.getY(1) - event.getY(0);
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
beforeLenght = (float) Math.sqrt( (moveX*moveX) + (moveY*moveY) );
break;
case MotionEvent.ACTION_MOVE:
//得到两个点之间的长度
afterLenght = (float) Math.sqrt( (moveX*moveX) + (moveY*moveY) );
float gapLenght = afterLenght - beforeLenght;
if(gapLenght == 0) {
break;
}
//如果当前时间两点距离大于前一时间两点距离，则传0，否则传1
if(gapLenght>0) {
this.setScale(scale,0);
}else {
this.setScale(scale,1);
}
; beforeLenght = afterLenght;
break;
}
}
//这里来监听屏幕触控时间
@Override
public boolean onTouchEvent(MotionEvent event) {
if(event.getY() > this.getTop() && event.getY() < this.getBottom()
&& event.getX() > this.getLeft() && event.getX() < this.getRight()) {
if(event.getPointerCount() == 2) {
this.scaleWithFinger(event);
}else if(event.getPointerCount() == 1) {
this.moveWithFinger(event);
}
}
return true;
}
}
