本文实例讲述了android编程滑动效果之gallery+gridview实现图片预览功能。分享给大家供大家参考，具体如下：
android系统自带一个gridview和gallery两个控件，gridview网格显示，gallery单个浏览，两者结合起来可以真正实现gallery浏览图片效果。
本示例通过gridview和gallery两个控件，模仿实现一个完整的仿gallery图像集的图片浏览效果。效果图如下：
1、gridview
首先，自定义一个gridimageadapter图片适配器，用于填充gridview控件的图片
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public class gridimageadapter extends baseadapter {
private context mcontext;
drawable btndrawable;
public gridimageadapter(context context) {
mcontext = context;
resources resources = context.getresources();
btndrawable = resources.getdrawable(r.drawable.bg);
}
@override
public int getcount() {
return imagesource.mthumbids.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) {
imageviewext imageview;
int space;
if (convertview == null) {
imageview = new imageviewext(mcontext);
if (imagecol == 5) {
space = dm.heightpixels / imagecol - 6;
imageview.setlayoutparams(new gridview.layoutparams(space, space));
} else {
space = dm.widthpixels / imagecol - 6;
imageview.setlayoutparams(new gridview.layoutparams( space, space));
}
imageview.setadjustviewbounds(true);
imageview.setscaletype(imageview.scaletype.center_crop); // 缩放图片使其长和宽一样
imageview.setpadding(3, 3, 3, 3);
} else {
imageview = (imageviewext) convertview;
}
imageview.setimageresource(imagesource.mthumbids[position]);
return imageview;
}
}
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然后，用gridimageadapter填充gridview
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gridview = (gridview) findviewbyid(r.id.mygrid);
gridimageadapter = new gridimageadapter(this);
gridview.setadapter(gridimageadapter);
gridview.setonitemclicklistener(listener); // 设置点击监听事件
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最后，设置gridview控件的点击监听事件
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adapterview.onitemclicklistener listener = new adapterview.onitemclicklistener() {
@override
public void onitemclick(adapterview<?> arg0, view arg1, int position, long id) {
intent intent = new intent();
intent.setclass(gridviewactivity.this, galleryactivity.class);
intent.putextra("position", position);
startactivity(intent);
}
};
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2、gallery
完成了gridview的图片显示、监听事件后，现在点击图片，会启动一个activity来显示当前点击的图片，此时显示图片的控件便是gallery
首先，同gridview一样，自定义一个imageadapter图片适配器，用来填充gallery
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public class imageadapter extends baseadapter {
private context mcontext;
private int mpos;
public imageadapter(context context) {
mcontext = context;
}
public void setownposition(int ownposition) {
this.mpos = ownposition;
}
public int getownposition() {
return mpos;
}
@override
public int getcount() {
return imagesource.mthumbids.length;
}
@override
public object getitem(int position) {
mpos=position;
return position;
}
@override
public long getitemid(int position) {
mpos=position;
return position;
}
@override
public view getview(int position, view convertview, viewgroup parent) {
mpos=position;
imageview imageview = new imageview(mcontext);
imageview.setbackgroundcolor(0xff000000);
imageview.setscaletype(imageview.scaletype.fit_center);
imageview.setlayoutparams(new mygallery.layoutparams(layoutparams.match_parent, layoutparams.match_parent));
imageview.setimageresource(imagesource.mthumbids[position]);
return imageview;
}
}
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然后，用imageadapter填充gallery
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mygallery galllery = (mygallery) findviewbyid(r.id.mygallery);
intent intent = getintent();
position = intent.getintextra("position", 0); // 获取gridviewactivity传来的图片位置position
imageadapter imgadapter=new imageadapter(this);
galllery.setadapter(imgadapter); // 设置图片imageadapter
galllery.setselection(position); // 设置当前显示图片
animation an= animationutils.loadanimation(this,r.anim.scale ); // gallery动画
galllery.setanimation(an);
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此时，如果细心可以注意到，我们的gallery也是自己定义的mygallery，具体定义如下：
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public class mygallery extends gallery {
boolean isfirst = false;
boolean islast = false;
public mygallery(context context) {
super(context);
}
public mygallery(context context, attributeset paramattributeset) {
super(context, paramattributeset);
}
/** 是否向左滑动（true - 向左滑动； false - 向右滑动） */
private boolean isscrollingleft(motionevent e1, motionevent e2) {
return e2.getx() > e1.getx();
}
@override
public boolean onfling(motionevent e1, motionevent e2, float distancex, float distancey) {
imageadapter ia = (imageadapter) this.getadapter();
int p = ia.getownposition(); // 获取当前图片的position
int count = ia.getcount(); // 获取全部图片的总数count
int kevent;
if (isscrollingleft(e1, e2)) {
if (p == 0 && isfirst) {
toast.maketext(this.getcontext(), "已是第一页", toast.length_short).show();
} else if (p == 0) {
isfirst = true;
} else {
islast = false;
}
kevent = keyevent.keycode_dpad_left;
} else {
if (p == count - 1 && islast) {
toast.maketext(this.getcontext(), "已到最后一页", toast.length_short).show();
} else if (p == count - 1) {
islast = true;
} else {
isfirst = false;
}
kevent = keyevent.keycode_dpad_right;
}
onkeydown(kevent, null);
return true;
}
}
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galleryactivity的布局文件gallery.xml
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<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="horizontal"
android:padding="10dip" >
<relativelayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#000000"
android:padding="2dip" >
<com.homer.gridgallery.mygallery
android:id="@+id/mygallery"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:spacing="16dp" />
</relativelayout>
</linearlayout>
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完整实例代码点击此处本站下载。
希望本文所述对大家android程序设计有所帮助。