关于WebView的手势监听问题

2011-11-22 10:07:45 1k 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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大致内容是这样的，做了个手势监听的demo，但是加载的webview手势没有效果，之后在网上找到了解决方案，让MyWebView类继承WebView类，重写onTouchEvent方法，将其显式的传给ViewFlipper。手势监听能起作用了。但是又有问题了，比如我WebView载入的url是www.baidu.com 如此在百度显示首页的时候可以实现手势监听，但是再点进去一层，比如进入百度知道以后手势监听有没有响应了。WebView的onTouchEvent方法好像没有执行。下面是我的代码：
MyWebView.java

public class MyWebView extends WebView {



	float downXValue;

	long downTime;

	private ViewFlipper flipper;



	private float lastTouchX, lastTouchY;

	private boolean hasMoved = false;

	private Activity context;

	

	public MyWebView(Context context, ViewFlipper flipper) {

		super(context);

		this.context = (Activity) context;

		this.flipper = flipper;

		this.loadUrl("http://www.baidu.com");

	}



	public boolean onTouchEvent(MotionEvent evt) {



		boolean consumed = super.onTouchEvent(evt);

		if (isClickable()) {

			switch (evt.getAction()) {

			case MotionEvent.ACTION_DOWN:

				Log.d("lxy", "browser ---> down envent");

				lastTouchX = evt.getX();

				lastTouchY = evt.getY();

				downXValue = evt.getX();

				downTime = evt.getEventTime();

				hasMoved = false;

				break;

			case MotionEvent.ACTION_MOVE:

				hasMoved = moved(evt);

				break;

			case MotionEvent.ACTION_UP:

				float currentX = evt.getX();

				long currentTime = evt.getEventTime();

				float difference = Math.abs(downXValue - currentX);

				long time = currentTime - downTime;



				Log.i("Touch Event:", "Distance: " + difference + "px Time: "

						+ time + "ms");

				/** X轴滑动距离大于100，并且时间小于220ms,并且向X轴右方向滑动 && (time < 220) */

				if ((downXValue < currentX)

						&& (difference > 100 && (time < 220))) {

					/** 跳到上一页 */

					this.flipper.setInAnimation(AnimationUtils.loadAnimation(

							this.getContext(), R.layout.right_in));

					this.flipper.setOutAnimation(AnimationUtils.loadAnimation(

							this.getContext(), R.layout.right_out));



					flipper.showPrevious();

					Log.d("lxy", "getDisplayedChild() = " + flipper.getDisplayedChild());

					

					context.setTitle(Constant.TITLE_STR[flipper.getDisplayedChild()]);

				}

				/** X轴滑动距离大于100，并且时间小于220ms,并且向X轴左方向滑动 */

				if ((downXValue > currentX) && (difference > 100)

						&& (time < 220)) {

					/** 跳到下一页 */

					this.flipper.setInAnimation(AnimationUtils.loadAnimation(

							this.getContext(), R.layout.left_in));

					this.flipper.setOutAnimation(AnimationUtils.loadAnimation(

							this.getContext(), R.layout.left_out));

					flipper.showNext();

					Log.d("lxy", "getDisplayedChild() = " + flipper.getDisplayedChild());

					context.setTitle(Constant.TITLE_STR[flipper.getDisplayedChild()]);

				}



				break;

			}

		}

		return consumed || isClickable();

	}



	private boolean moved(MotionEvent evt) {

		return hasMoved || Math.abs(evt.getX() - lastTouchX) > 10.0

				|| Math.abs(evt.getY() - lastTouchY) > 10.0;

	}



}

下面是SignFlipDemo.java

public class SignFlipDemo extends Activity implements OnGestureListener {

	

	/** Called when the activity is first created. */

	private static ViewFlipper flipper;

	private GestureDetector detector;



	@Override

	public void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		detector = new GestureDetector(this);//  分析用户动作

		flipper = new ViewFlipper(this);

		flipper.setBackgroundColor(Color.WHITE);

		flipper.addView(addTextView("step 1", 0));//

		flipper.addView(addTextView("step 2", 1));

		flipper.addView(addTextView("step 3", 2));

		setContentView(flipper);

		setTitle(Constant.TITLE_STR[0]);

	}



	private View addTextView(String text, int i) {

		TextView tv = new TextView(this);

		tv.setText(text);

		tv.setGravity(1);

		Drawable dabg;

		switch (i) {

		case 0:

			dabg = this.getResources().getDrawable(R.drawable.videocolumn);

			tv.setBackgroundDrawable(dabg);

			return tv;

		

		case 1:

			dabg = this.getResources().getDrawable(R.drawable.playback);

			tv.setBackgroundDrawable(dabg);

			return tv;

			

		case 2:

			MyWebView webView = new MyWebView(this, flipper);

			return webView;

		}

		return null;

	}



	@Override

	public boolean onTouchEvent(MotionEvent event) {

		return this.detector.onTouchEvent(event);

	}



	@Override

	public boolean onDown(MotionEvent e) {

		return false;

	}



	@Override

	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,

			float velocityY) {

		if (e1.getX() - e2.getX() > 60) {

			flipper.setInAnimation(AnimationUtils.loadAnimation(this,

					R.layout.left_in));

			flipper.setOutAnimation(AnimationUtils.loadAnimation(this,

					R.layout.left_out));

			flipper.showNext();

			Log.d("lxy", "getDisplayedChild() = " + flipper.getDisplayedChild());

			this.setTitle(Constant.TITLE_STR[flipper.getDisplayedChild()]);

			return true;

		} else if (e1.getX() - e2.getX() < -60) {

			flipper.setInAnimation(AnimationUtils.loadAnimation(this,

					R.layout.right_in));

			flipper.setOutAnimation(AnimationUtils.loadAnimation(this,

					R.layout.right_out));

			flipper.showPrevious();

			Log.d("lxy", "getDisplayedChild() = " + flipper.getDisplayedChild());

			this.setTitle(Constant.TITLE_STR[flipper.getDisplayedChild()]);

			return true;

		}

		return false;

	}



	@Override

	public void onLongPress(MotionEvent e) {

	}



	@Override

	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,

			float distanceY) {

		return false;

	}



	@Override

	public void onShowPress(MotionEvent e) {

	}



	@Override

	public boolean onSingleTapUp(MotionEvent e) {

		return false;

	}

}