GestureDetector

最新推荐文章于 2025-05-28 19:00:02 发布

new_xd

最新推荐文章于 2025-05-28 19:00:02 发布

阅读量491

点赞数

CC 4.0 BY-SA版权

分类专栏： Android碎碎念文章标签： GestureDetector

本文链接：https://blog.youkuaiyun.com/u010349699/article/details/21990537

Android碎碎念专栏收录该内容

11 篇文章

订阅专栏

本文介绍如何利用GestureDetector处理Android应用中的滑动事件。通过实现GestureDetector.OnGestureListener接口，开发者可以获取到滑动的起始点、终点及速度等信息，进而判断滑动事件并作出响应。示例代码展示了如何为ViewFlipper组件注册触摸监听器来响应滑动。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

用GestureDetector可以处理滑动事件
public GestureDetector (Context context, GestureDetector.OnGestureListener listener)
public GestureDetector (Context context, GestureDetector.OnGestureListener listener, Handler handler)

其中的onGestureListener有
boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) 方法
e1表示开始点，e2表示结束点， velocityX表示X轴方向的分速度， velocityY表示Y方向的分速度
这样 e2.getX() - e1.getX() 就可以表示X轴方向滑动距离,
通过这些数据就可以判断是否产生了滑动事件，从而进行相应的处理.

想要GestureDetector起作用,需要
1. 给需要响应滑动事件的view注册View.OnTouchListener
2. 在OnTouchListener的onTouch方法中，如下
public boolean onTouch(View arg0, MotionEvent arg1) {
return detector.onTouchEvent(arg1); //detector是GestureDetector的实例
}

代码和ViewFlipper的一样

package com.example.howtouseviewflipper;

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.ViewFlipper;

public class MainActivity extends Activity {

	private ViewFlipper vf;
	private Button btn;
	private String list1[] = {"list1", "1", "2", "3", "4", "5", "6", "7"};
	private String list2[] = {"list2", "lion", "tiger", "monkey", "rabbit", "cat", "dog", "snake", "frog"};
	private String list3[] = {"list3", "red", "yellow", "blue", "green", "purple", "orange", "white", "black", "grey"};
	private GestureDetector gd;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		vf = (ViewFlipper) findViewById(R.id.viewflipper);
		
		ListView lv1 = new ListView(this);
		ArrayAdapter aa1 = new ArrayAdapter(this, android.R.layout.simple_list_item_1, list1);
		lv1.setAdapter(aa1);
		ListView lv2 = new ListView(this);
		ArrayAdapter aa2 = new ArrayAdapter(this, android.R.layout.simple_list_item_1, list2);
		lv2.setAdapter(aa2);
		ListView lv3 = new ListView(this);
		ArrayAdapter aa3 = new ArrayAdapter(this, android.R.layout.simple_list_item_1, list3);
		lv3.setAdapter(aa3);
		View.OnTouchListener vot = new View.OnTouchListener() {
			
			@Override
			public boolean onTouch(View arg0, MotionEvent arg1) {
				// TODO Auto-generated method stub
				return gd.onTouchEvent(arg1);
			}
		};
		AdapterView.OnItemClickListener aaso = new AdapterView.OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView arg0, View arg1, int arg2,
					long arg3) {
				// TODO Auto-generated method stub
				Toast.makeText(MainActivity.this, "OnItemClick "+ arg2, Toast.LENGTH_SHORT).show();
			}
			
		};
		lv1.setOnTouchListener(vot);
		lv2.setOnTouchListener(vot);
		lv3.setOnTouchListener(vot);
		lv1.setOnItemClickListener(aaso);
		lv2.setOnItemClickListener(aaso);
		lv3.setOnItemClickListener(aaso);
		vf.addView(lv1, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
		vf.addView(lv2, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
		vf.addView(lv3, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
//		for(int i = 0; i< list2.length; i++) {
//			TextView tv = new TextView(this);
//			tv.setText(list2[i]);
//			vf.addView(tv, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
//		}
		gd = new GestureDetector(this, new GestureDetector.OnGestureListener() {
			
			@Override
			public boolean onSingleTapUp(MotionEvent arg0) {
				// TODO Auto-generated method stub
				return false;
			}
			
			@Override
			public void onShowPress(MotionEvent arg0) {
				// TODO Auto-generated method stub
				
			}
			
			@Override
			public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
					float arg3) {
				// TODO Auto-generated method stub
				return false;
			}
			
			@Override
			public void onLongPress(MotionEvent arg0) {
				// TODO Auto-generated method stub
				
			}
			
			@Override
			public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2,
					float arg3) {
				// TODO Auto-generated method stub
				if(arg1.getX() - arg0.getX() > 120) {
					vf.showPrevious();
					return true;
				}
				if(arg1.getX() - arg0.getX() < -120) {
					vf.showNext();
					return true;
				}
				return false;
			}
			
			@Override
			public boolean onDown(MotionEvent arg0) {
				// TODO Auto-generated method stub
				return false;
			}
		});
		
		btn = (Button)findViewById(R.id.btn);
		btn.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				if(vf.isFlipping()){
					vf.stopFlipping();
					btn.setText(R.string.start);
				}else {
					vf.startFlipping();
					btn.setText(R.string.stop);
				}
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

//  当ViewFlipper中的view是TextView时,在这个地方用GestureDetector是好用的，但是如果是ListView,就不行了
//	@Override
//	public boolean onTouchEvent(MotionEvent event) {
//		// TODO Auto-generated method stub
//		return gd.onTouchEvent(event);
//	}

}