说到左右滑动,其实实现左右滑动的方式很多,有ViewPaer,自定义实现Viewgroup,gallery等都可以达到这种效果。这里做下ViewFliper实现左右滑动的效果。
会用到以下的技术:
1、ViewFlipper
2、GestureDetector
3、Animation
主要是这三个类在起作用。
ViewFlipper,不妨把它看做一个容器吧,你可以把许多的View放在这个容器中,让它展示给用户,虽然它每次只展示一个view,我感觉它的用途更好是作为广告展示,比如类似购物网站那样的广告滚动展示。比如可以设置自动播放功能,就可以滚动广告了!

原理:向左向右滑动主要是依赖手势来控制,手势向右滑动就调用 viewFlipper.showNext()方法,同理,向左滑动就会去调用viewFlipper.showPrevious()方法。

效果图如下:


接下来直接上代码:

首先在布局文件中添加ViewFlipper的标签:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/pattern1" >

    <Button
        android:id="@+id/treasure_chest_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:background="@drawable/treasure" />

    <ViewFlipper
        android:id="@+id/viewflipper"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/treasure_chest_btn" >
    </ViewFlipper>

    <Button
        android:id="@+id/garbage_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@id/viewflipper"
        android:background="@drawable/garbage" />

</RelativeLayout>
其次是在anim中定义动画:
slide_left_in.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <!--
     画面转换位置移动动画效果 
     开始向左动画
     fromXDelta : 动画开始时 X坐标位置
     toXDelta :动画结束时 X坐标位置
     duration :动画持续时间
    -->
    <translate
        android:duration="800"
        android:fromXDelta="100%p"
        android:toXDelta="0" />

</set>
slide_left_out.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="800"
        android:fromXDelta="0"
        android:toXDelta="-100%p" />

</set>
slide_right_in.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="800"
        android:fromXDelta="-100%p"
        android:toXDelta="0" />

</set>
slide_right_out.xml:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="800"
        android:fromXDelta="0"
        android:toXDelta="100%p" />

</set>
最后是Activity中的实现:

package net.loonggg.demo.slider;

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.AnimationSet;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ViewFlipper;

public class MainActivity extends Activity implements OnGestureListener,
		OnTouchListener {
	private GestureDetector detector;
	private ViewFlipper myViewFlipper;
	private int[] imgs = { R.drawable.img0, R.drawable.img1, R.drawable.img2,
			R.drawable.img3, R.drawable.img4, R.drawable.img5 };
	private int displayedChildIndex = 0;

	private Button treasure_btn;
	private Button garbage_btn;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.main);
		myViewFlipper = (ViewFlipper) findViewById(R.id.viewflipper);
		treasure_btn = (Button) findViewById(R.id.treasure_chest_btn);
		garbage_btn = (Button) findViewById(R.id.garbage_btn);
		myViewFlipper.setOnTouchListener(this);
		myViewFlipper.setLongClickable(true);// 设置长按事件

		// myViewFlipper.setAutoStart(true);// 设置是否自动播放,默认不自动播放

		detector = new GestureDetector(this);
		addFlipperView();
	}

	/**
	 * 向FlipperView中动态添加View
	 */
	private void addFlipperView() {
		for (int i = 0; i < imgs.length; i++) {
			View view = LayoutInflater.from(this).inflate(
					R.layout.myviewflipper, null);
			TextView title = (TextView) view.findViewById(R.id.view_title);
			title.setText("头像");
			ImageView iv = (ImageView) view.findViewById(R.id.view_image);
			iv.setBackgroundResource(imgs[i]);
			myViewFlipper.addView(view);
		}
	}

	@Override
	public boolean onDown(MotionEvent e) {
		return false;
	}

	@Override
	public void onShowPress(MotionEvent e) {

	}

	@Override
	public boolean onSingleTapUp(MotionEvent e) {
		return false;
	}

	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
			float distanceY) {
		return false;
	}

	@Override
	public void onLongPress(MotionEvent e) {

	}

	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
		// 返回当前正在显示的子视图的索引
		displayedChildIndex = myViewFlipper.getDisplayedChild();
		final ImageView iv = (ImageView) myViewFlipper.getChildAt(
				displayedChildIndex).findViewById(R.id.view_image);
		if (e2.getX() - e1.getX() >= 100 && e1.getY() - e2.getY() >= 100) {
			AnimationSet outAnim = (AnimationSet) AnimationUtils.loadAnimation(
					this, R.anim.collect_treasure);
			iv.startAnimation(outAnim);
			outAnim.setAnimationListener(new AnimationListener() {

				public void onAnimationStart(Animation animation) {

				}

				public void onAnimationRepeat(Animation animation) {

				}

				public void onAnimationEnd(Animation animation) {
					showNextView();
					AnimationSet downAnim = (AnimationSet) AnimationUtils
							.loadAnimation(MainActivity.this, R.anim.up_or_down);
					treasure_btn.setAnimation(downAnim);
					iv.clearAnimation();
				}
			});

		} else if (e1.getX() - e2.getX() >= 100 && e2.getY() - e1.getY() >= 100) {
			AnimationSet outAnim = (AnimationSet) AnimationUtils.loadAnimation(
					this, R.anim.throw_garbage);
			iv.startAnimation(outAnim);
			outAnim.setAnimationListener(new AnimationListener() {

				public void onAnimationStart(Animation animation) {

				}

				public void onAnimationRepeat(Animation animation) {

				}

				public void onAnimationEnd(Animation animation) {
					showNextView();
					AnimationSet leftAnim = (AnimationSet) AnimationUtils
							.loadAnimation(MainActivity.this,
									R.anim.left_or_right);
					garbage_btn.setAnimation(leftAnim);
					iv.clearAnimation();
				}
			});

		} else if (e1.getX() - e2.getX() >= 100) {
			showNextView();
		} else if (e2.getX() - e1.getX() >= 100) {
			showPreviousView();
		}
		return false;
	}

	private void showPreviousView() {
		myViewFlipper.setInAnimation(AnimationUtils.loadAnimation(this,
				R.anim.slide_right_in));
		myViewFlipper.setOutAnimation(AnimationUtils.loadAnimation(this,
				R.anim.slide_right_out));
		myViewFlipper.showPrevious();
	}

	private void showNextView() {
		myViewFlipper.setInAnimation(AnimationUtils.loadAnimation(this,
				R.anim.slide_left_in));
		myViewFlipper.setOutAnimation(AnimationUtils.loadAnimation(this,
				R.anim.slide_left_out));
		myViewFlipper.showNext();

	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		return detector.onTouchEvent(event);
	}

}
转载请注明出处:http://blog.csdn.net/loongggdroid/article/details/18262543

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