android 图片操作(缩放移动) 实例代码
view_show.xml
<?xml version="1.0" encoding="utf-8"?>
<linearlayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<framelayout
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<imageview
android:id="@+id/view_img"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:background="@drawable/camera_gray"/>
<imagebutton
android:id="@+id/view_close"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="top|left"
android:layout_margin="5dip"/>
<imagebutton
android:id="@+id/view_del"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="top|right"
android:layout_margin="5dip"/>
<imagebutton
android:id="@+id/view_narrow"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:layout_marginright="10dip"/>
<imagebutton
android:id="@+id/view_amplification"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:layout_marginleft="10dip"/>
</framelayout>
</linearlayout>
galleryviewtouch.java:
package com.kotei.lbs.anthurium.lawcases;
import android.app.activity;
import android.graphics.bitmap;
import android.graphics.bitmapfactory;
import android.graphics.matrix;
import android.graphics.pointf;
import android.graphics.rectf;
import android.os.bundle;
import android.util.displaymetrics;
import android.util.floatmath;
import android.util.log;
import android.view.motionevent;
import android.view.view;
import android.view.window;
import android.view.view.ontouchlistener;
import android.widget.imageview;
import android.widget.imageview.scaletype;
/**
* 查看图片的操作
* @author hongj
*/
public class galleryviewtouch extends activity {
private imageview iv;
private bitmap bitmap=null;
matrix matrix = new matrix();
matrix savedmatrix = new matrix();
displaymetrics dm;
float minscaler;// 最小缩放比例
static final float max_scale = 4f;// 最大缩放比例
static final int none = 0;// 初始状态
static final int drag = 1;// 拖动
static final int zoom = 2;// 缩放
int mode = none;
pointf prev = new pointf();
pointf mid = new pointf();
float dist = 1f;
/** called when the activity is first created. */
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
requestwindowfeature(window.feature_no_title);
setcontentview(r.layout.view_show);
dm = new displaymetrics();
getwindowmanager().getdefaultdisplay().getmetrics(dm);// 获取分辨率
bitmap=bitmapfactory.decoderesource(getresources(), r.drawable.bottom_layout_background);
iv=(imageview)findviewbyid(r.id.view_img);
iv.setimagebitmap(bitmap);
iv.setontouchlistener(new imagetouch(bitmap,dm.widthpixels,dm.heightpixels,iv));
}
class imagetouch implements ontouchlistener {
private imageview iv;
private bitmap bitmap=null;
matrix matrix = new matrix();
matrix savedmatrix = new matrix();
int dmwidth,dmheight;
float minscaler;// 最小缩放比例
static final float max_scale = 4f;// 最大缩放比例
static final int none = 0;// 初始状态
static final int drag = 1;// 拖动
static final int zoom = 2;// 缩放
int mode = none;
pointf prev = new pointf();
pointf mid = new pointf();
float dist = 1f;
imagetouch(bitmap bitmap,int width,int height,imageview iv){
this.bitmap= bitmap;
this.dmwidth=width;
this.dmheight=height;
this.iv=iv;
initimage();
}
public void initimage(){
if (dmwidth < bitmap.getwidth()|| dmheight < bitmap.getheight()) {
minzoom();
center();
iv.setimagematrix(matrix);
} else {
iv.setscaletype(scaletype.center);
}
}
@override
public boolean ontouch(view v, motionevent event) {
switch (event.getaction() & motionevent.action_mask) {
// 主点按下
case motionevent.action_down:
log.d("system.out", "action_down");
savedmatrix.set(matrix);
prev.set(event.getx(), event.gety());
mode = drag;
break; // 副点按下
case motionevent.action_pointer_down:
log.d("system.out", "action_pointer_down");
dist = spacing(event); // 如果连续两点距离大于10，则判定为多点模式
if (spacing(event) > 10f) {
savedmatrix.set(matrix);
midpoint(mid, event);
mode = zoom;
}
break;
case motionevent.action_up:
case motionevent.action_pointer_up:
mode = none;
break;
case motionevent.action_move:
if (mode == drag) {
matrix.set(savedmatrix);
matrix.posttranslate(event.getx() - prev.x, event.gety()
- prev.y);
} else if (mode == zoom) {
float newdist = spacing(event);
if (newdist > 10f) {
matrix.set(savedmatrix);
float tscale = newdist / dist;
matrix.postscale(tscale, tscale, mid.x, mid.y);
}
}
break;
}
iv.setimagematrix(matrix);
if(mode!=none)
checkview();
return true;
}
private void checkview() {
float p[] = new float[9];
matrix.getvalues(p);
if (mode == zoom) {
if (p[0] < minscaler) {
matrix.setscale(minscaler, minscaler);
}
if (p[0] > max_scale) {
matrix.set(savedmatrix);
}
}
center();
}
public void minzoom() {
log.i("test", bitmap.getwidth()+"");
log.i("test", bitmap.getheight()+"");
minscaler = math.min(
(float) dmwidth / (float) bitmap.getwidth(),
(float) dmheight / (float) bitmap.getheight());
if (minscaler < 1.0) {
matrix.postscale(minscaler, minscaler);
}
}
protected void center(boolean horizontal, boolean vertical) {
matrix m = new matrix();
m.set(matrix);
rectf rect = new rectf(0, 0, bitmap.getwidth(), bitmap.getheight());
m.maprect(rect);
float height = rect.height();
float width = rect.width();
log.d("system.out",rect.top+"************"+ rect.bottom);
float deltax = 0, deltay = 0;
if (vertical) { // 图片小于屏幕大小，则居中显示。大于屏幕，上方留空则往上移，下方留空则往下移
int screenheight = dmheight;
if (height < screenheight) {
deltay = (screenheight - height) / 2 - rect.top;
} else if (rect.top > 0) {
deltay = -rect.top;
} else if (rect.bottom < screenheight) {
deltay = iv.getheight() - rect.bottom;
}
//deltay-=50;
}
if (horizontal) {
int screenwidth = dmwidth;
if (width < screenwidth) {
deltax = (screenwidth - width) / 2 - rect.left;
} else if (rect.left > 0) {
deltax = -rect.left;
} else if (rect.right < screenwidth) {
deltax = screenwidth - rect.right;
}
}
matrix.posttranslate(deltax, deltay);
}
public void center() {
center(true, true);
}
private float spacing(motionevent event) {
float x = event.getx(0) - event.getx(1);
float y = event.gety(0) - event.gety(1);
return floatmath.sqrt(x * x + y * y);
}
/** * 两点的中点 */
private void midpoint(pointf point, motionevent event) {
float x = event.getx(0) + event.getx(1);
float y = event.gety(0) + event.gety(1);
point.set(x / 2, y / 2);
}
}
}