Android 使用多向滑动手势查看

Question

我有一个包含长文本的 TextView 视图，因此该视图必须为用户提供滚动文本的便利。

此外，此 TextView 必须允许在视图的所有实例上左右滑动。

我可以使用 scollingMovementMethod 滚动，但左右滑动不起作用。

Answer 1

要启用向左、向右、向上或向下滑动手势，请遵循以下步骤：

步骤 1： 创建一个 java 文件 SimpleGestureFilter

import android.app.Activity;
import android.view.GestureDetector;
import android.view.MotionEvent;

/**
* Created by nihal on 1/21/2016.
*/
public class SimpleGestureFilter extends  
 GestureDetector.SimpleOnGestureListener {
public final static int SWIPE_UP= 1;
public final static int SWIPE_DOWN= 2;
public final static int SWIPE_LEFT= 3;
public final static int SWIPE_RIGHT = 4;
public final static int MODE_TRANSPARENT = 0;
public final static int MODE_SOLID= 1;
public final static int MODE_DYNAMIC= 2;
private final static int ACTION_FAKE = -13; //just an unlikely number
private int swipe_Min_Distance = 100;
private int swipe_Max_Distance = 350;
private int swipe_Min_Velocity = 100;
private int mode = MODE_DYNAMIC;
private boolean running = true;
private boolean tapIndicator = false;
private Activity context;
private GestureDetector detector;
private SimpleGestureListener listener;
public SimpleGestureFilter(Activity context,SimpleGestureListener sgl) {

    this.context = context;
    this.detector = new GestureDetector(context, this);
    this.listener = sgl;
}
public void onTouchEvent(MotionEvent event){

    if(!this.running)
        return;

    boolean result = this.detector.onTouchEvent(event);

    if(this.mode == MODE_SOLID)
        event.setAction(MotionEvent.ACTION_CANCEL);
    else if (this.mode == MODE_DYNAMIC) {

        if(event.getAction() == ACTION_FAKE)
            event.setAction(MotionEvent.ACTION_UP);
        else if (result)
            event.setAction(MotionEvent.ACTION_CANCEL);
        else if(this.tapIndicator){
            event.setAction(MotionEvent.ACTION_DOWN);
            this.tapIndicator = false;
        }

    }
    //else just do nothing, it's Transparent
}
public void setMode(int m){
    this.mode = m;
}
public int getMode(){
    return this.mode;
}
public void setEnabled(boolean status){
    this.running = status;
}
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                       float velocityY) {

    try {
        if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH) {
            return false;
        }
        // right to left swipe
        if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) { // right to left
            this.listener.onSwipe(SWIPE_LEFT);



        }if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) { // right to left
            this.listener.onSwipe(SWIPE_RIGHT);



        } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) { //    bottom to up
            this.listener.onSwipe(SWIPE_UP);



        }

    } catch (Exception e) {

    }
    return false;
}

@Override
public boolean onSingleTapUp(MotionEvent e) {
    this.tapIndicator = true;
    return false;
}
@Override
public boolean onDoubleTap(MotionEvent arg0) {
    this.listener.onDoubleTap();;
    return true;
}

@Override
public boolean onDoubleTapEvent(MotionEvent arg0) {
    return true;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent arg0) {

    if(this.mode == MODE_DYNAMIC){// we owe an ACTION_UP, so we fake an      
        arg0.setAction(ACTION_FAKE);//action which will be converted to an ACTION_UP later.                                   
        this.context.dispatchTouchEvent(arg0);
    }
    return false;
}

public interface SimpleGestureListener{
    void onSwipe(int direction);
    void onDoubleTap();
}

}

步骤 2： 扩展 AppCompatActivity 并实现 SimpleGestureFilter.SimpleGestureListener 在你的 Activity 中像这样：

public class YourActivity extends AppCompatActivity implements     
SimpleGestureFilter.SimpleGestureListener {
     //inside of activity, code here
  }

第 3 步： 定义

private SimpleGestureFilter detector;

Step4: 在你的 onCreate 方法中添加：

detector = new SimpleGestureFilter(this,this);

现在你的Activity应该是这样的

public class YourActivity extends AppCompatActivity implements    

SimpleGestureFilter.SimpleGestureListener {

private SimpleGestureFilter detector;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.yourlayout);
    detector = new SimpleGestureFilter(this,this);

}

 // add codes for Swipe Gesture here


 }

第 5 步：在你的Activity中添加滑动手势的代码

public class sources extends AppCompatActivity implements 
SimpleGestureFilter.SimpleGestureListener {

private SimpleGestureFilter detector;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.sources);
    detector = new SimpleGestureFilter(this,this);

}



@Override
public boolean dispatchTouchEvent(MotionEvent me){

    this.detector.onTouchEvent(me);

    return super.dispatchTouchEvent(me);

}
@Override

public void onSwipe(int direction) {
    String str = "";



    switch (direction) {

        case SimpleGestureFilter.SWIPE_RIGHT :

            //**code** here for what you wanna do with **Right Swipe**

        case SimpleGestureFilter.SWIPE_LEFT :
           //**code** here for what you wanna do with **Left Swipe**


        case SimpleGestureFilter.SWIPE_DOWN :

            break;

        case SimpleGestureFilter.SWIPE_UP :

            break;

    }



}




@Override

public void onDoubleTap() {

    Toast.makeText(this, "Try swiping left", Toast.LENGTH_LONG).show();

}

正确执行以上所有步骤，您将能够使滑动手势正常工作

Android 使用多向滑动手势查看

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