(Android) 单击屏幕事件和滑动屏幕事件共存的解决方案 - android

Android技术学习，更多知识请访问https://www.itkc8.com　

实现功能：布局文件中有两个控件，分别是ImageSwitcher和Gallery控件，Gallery默认的情况下是不可见的。当进入程序的界面时，如果滑动屏幕，会切换到下一张或者前一张图片，根据你滑动屏幕的方向来判断，当单击屏幕时，会显示Gallery控件，再单击屏幕时，会隐藏Gallery控件，这个问题不是我自己解决的，通过论坛提问，AMinfo帮我解决的，感谢他。

心得：我解决这个问题的方案是：要实现两个监听器，分别是：OnTouchListener和OnGestureListener，怎么尝试都无法区分单击屏幕和滑动屏幕动作。AMinfo的解决方案是在OnTouchListener的重写onTouch方法中添加如下的代码，如果我在一个人这样做下去，我都不知道什么时候完成这么一个小功能呢？让我明白需要大家帮助的时候，不可一意孤行，不但浪费时间，而且伤身啊，当然，自己也要先想想怎么去解决这个问题喽。

[java] view plaincopyprint?

// 数字4和数字0分别表示的是不可见和可见，
// 也可以使用View.INVISIBLE和View.VISIBLE来代替数字.
else
{
if (gallery.getVisibility() == 4)
gallery.setVisibility(0);
else
gallery.setVisibility(4);
}

下面，贴上完整的小应用代码：

Album.java，项目中要用到的图片自己提供哦

[java] view plaincopyprint?

package com.treasure.ui;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Gallery.LayoutParams;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;
/**
* 实现相册浏览功能
*/
public class Album extends Activity implements OnItemSelectedListener, ViewFactory, OnTouchListener
{
private ImageSwitcher imageSwitcher;
private Gallery gallery;
private int selectedTag = 0;
private int downX, upX;
private Integer [] imagesId = new Integer[]{R.drawable.b, R.drawable.c, R.drawable.d,
R.drawable.f, R.drawable.g};
private Integer [] selectId = new Integer[]{R.drawable.b, R.drawable.c, R.drawable.d,
R.drawable.f, R.drawable.g};
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
imageSwitcher = (ImageSwitcher)findViewById(R.id.switcher);
imageSwitcher.setFactory(this);
//设置图片切换时的动画效果
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
imageSwitcher.setOnTouchListener(this);
gallery = (Gallery)findViewById(R.id.gallery);
//自定义ImageAdapter继承于BaseAdapter，是一个内部类
gallery.setAdapter(new ImageAdapter(this));
gallery.setOnItemSelectedListener(this);
}
@Override
public View makeView()
{
ImageView image = new ImageView(this);
image.setScaleType(ImageView.ScaleType.FIT_XY);
image.setLayoutParams(new ImageSwitcher.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
return image;
}
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3)
{
selectedTag = arg2;
imageSwitcher.setImageResource(imagesId[arg2]);
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{}
public class ImageAdapter extends BaseAdapter
{
private Context context;
int galleryItemBackground;
public ImageAdapter (Context c)
{
context = c;
TypedArray typeArray = obtainStyledAttributes(R.styleable.Gallery);
galleryItemBackground = typeArray.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0);
typeArray.recycle();
}
@Override
public int getCount()
{
//返回selectId[]的长度
return selectId.length;
}
@Override
public Object getItem(int position)
{
return position;
}
@Override
public long getItemId(int position)
{
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
ImageView imageView = new ImageView(context);
//设置资源图片
imageView.setImageResource(selectId[position]);
imageView.setAdjustViewBounds(true); //允许调整边框
//设定底部画廊，自适应大小
imageView.setLayoutParams(new Gallery.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
//设置画廊背景
imageView.setBackgroundResource(galleryItemBackground);
return imageView;
}
}
@Override
public boolean onTouch(View v, MotionEvent event)
{
if (event.getAction() == MotionEvent.ACTION_DOWN)
{
downX = (int)event.getX(); // 取得按下时的坐标x
return true;
}
else if (event.getAction() == MotionEvent.ACTION_UP)
{
upX = (int)event.getX(); // 取得松开时的坐标x;
if (upX - downX > 100)
{
// 从左拖到右，即看前一张
// 如果是第一，则去到尾部
if (gallery.getSelectedItemPosition() == 0)
selectedTag = gallery.getCount() - 1;
else
selectedTag = gallery.getSelectedItemPosition() - 1;
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
R.anim.push_right_in));
imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
R.anim.push_right_out));
}
else if (downX - upX > 100)
{
// 从右拖到左，即看后一张
// 如果是最后，则去到第一
if (gallery.getSelectedItemPosition()
== (gallery.getCount() - 1))
selectedTag = 0;
else
selectedTag = gallery.getSelectedItemPosition() + 1;
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
R.anim.push_left_in));
imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
R.anim.push_left_out));
}
else
{
if (gallery.getVisibility() == 4)
gallery.setVisibility(0);
else
gallery.setVisibility(4);
}
// 改变gallery图片所选，自动触发ImageSwitcher的setOnItemSelectedListener
gallery.setSelection(selectedTag, true);
return true;
}
return false;
}
}

res\layout\main.xml