Android编程实现图标拖动效果的方法

本文实例讲述了android编程实现图标拖动效果的方法。分享给大家供大家参考，具体如下：

最近优化图标拖动时的速率，稍微有一点点效果，直接把代码贴出来，有兴趣一起讨论的朋友可以给我留言。

代码如下:

dragview.java

package com.android.dragtest;
import android.content.context;
import android.util.attributeset;
import android.util.log;
import android.view.motionevent;
import android.view.view;
import android.widget.framelayout;
public class dragview extends framelayout {
 private static final string tag = "dragview";
 private float x;
 private float y;
 private view mdragview;
 public dragview(context context) {
  this(context, null);
 }
 public dragview(context context, attributeset attrs) {
  this(context, attrs, 0);
 }
 public dragview(context context, attributeset attrs, int defstyle) {
  super(context, attrs, defstyle);
  mdragview = new view(context);
  mdragview.setlayoutparams(new layoutparams(60, 60));
  mdragview.setbackgrounddrawable(getresources().getdrawable(r.drawable.gamecenter));
  mdragview.setvisibility(view.invisible);
  addview(mdragview);
 }
 public boolean onintercepttouchevent(motionevent ev) {
  final int action = ev.getaction();
  switch (action) {
  case motionevent.action_down:
   log.d(tag, "===============>onintercepttouchevent action_down");
   break;
  case motionevent.action_move:
   log.d(tag, "===============>onintercepttouchevent action_move");
   break;
  case motionevent.action_up:
   log.d(tag, "===============>onintercepttouchevent action_up");
   break;
  }
  return true;
 }
 public boolean ontouchevent(motionevent ev) {
  final int action = ev.getaction();
  x = ev.getx();
  y = ev.gety();
  switch (action) {
  case motionevent.action_down:
   log.d(tag, "ontouchevent action_down");
   mdragview.layout((int)x - 30, (int)y - 30, (int)x + 30, (int)y + 30);
   mdragview.setvisibility(view.visible);
   break;
  case motionevent.action_move:
   log.d(tag, "ontouchevent action_move x:" + x + " y:" + y);
   mdragview.layout((int)x - 30, (int)y - 30, (int)x + 30, (int)y + 30);
   break;
  case motionevent.action_up:
   log.d(tag, "ontouchevent action_up");
   mdragview.setvisibility(view.invisible);
   break;
  }
  return true;
 }
}

dragtestactivity.java

package com.android.dragtest;
import android.app.activity;
import android.os.bundle;
public class dragtestactivity extends activity {
 /** called when the activity is first created. */
 @override
 public void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.main);
 }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >
 <com.android.dragtest.dragview
  android:layout_width="match_parent"
  android:layout_height="match_parent">
 </com.android.dragtest.dragview>
</linearlayout>

希望本文所述对大家android程序设计有所帮助。