我想让飞的手势检测工作在我的Android应用程序。

我有一个GridLayout,包含9个ImageViews。来源可以在这里找到:罗曼家伙的网格布局。

我从Romain Guy的Photostream应用程序中获取的文件只做了轻微的修改。

对于简单的点击情况,我只需要为每个ImageView设置onClickListener,我添加为实现View.OnClickListener的主要活动。实现能够识别投掷的东西似乎要复杂得多。我猜这是因为它可能跨越不同的观点?

If my activity implements OnGestureListener I don't know how to set that as the gesture listener for the Grid or the Image views that I add. public class SelectFilterActivity extends Activity implements View.OnClickListener, OnGestureListener { ... If my activity implements OnTouchListener then I have no onFling method to override (it has two events as parameters allowing me to determine if the fling was noteworthy). public class SelectFilterActivity extends Activity implements View.OnClickListener, OnTouchListener { ... If I make a custom View, like GestureImageView that extends ImageView I don't know how to tell the activity that a fling has occurred from the view. In any case, I tried this and the methods weren't called when I touched the screen.

我真的需要一个跨视图工作的具体例子。我应该在什么时候以及如何附加这个侦听器?我还需要能够检测单个点击。

// Gesture detection
mGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {

    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        int dx = (int) (e2.getX() - e1.getX());
        // don't accept the fling if it's too short
        // as it may conflict with a button push
        if (Math.abs(dx) > MAJOR_MOVE && Math.abs(velocityX) > Math.absvelocityY)) {
            if (velocityX > 0) {
                moveRight();
            } else {
                moveLeft();
            }
            return true;
        } else {
            return false;
        }
    }
});

是否有可能在我的屏幕上方放置一个透明的视图来捕捉投掷?

如果我选择不从XML膨胀我的子图像视图,我可以通过手势检测器作为构造函数参数到我创建的ImageView的新子类吗?

这是一个非常简单的活动,我试图让飞动检测工作:SelectFilterActivity(改编自photostream)。

我一直在看这些资料:

检测手势-教程 SDK文档 计算器的代码

到目前为止,什么都没用,我希望能得到一些指导。


当前回答

我做的有点不同,并编写了一个额外的检测器类来实现View.onTouchListener

onCreateis简单地把它添加到最低的布局,就像这样:

ActivitySwipeDetector activitySwipeDetector = new ActivitySwipeDetector(this);
lowestLayout = (RelativeLayout)this.findViewById(R.id.lowestLayout);
lowestLayout.setOnTouchListener(activitySwipeDetector);

在id。lowestLayout是id。在布局层次结构中最低的视图使用了xxx, lowestLayout被声明为RelativeLayout

然后是实际的活动滑动检测器类:

public class ActivitySwipeDetector implements View.OnTouchListener {

static final String logTag = "ActivitySwipeDetector";
private Activity activity;
static final int MIN_DISTANCE = 100;
private float downX, downY, upX, upY;

public ActivitySwipeDetector(Activity activity){
    this.activity = activity;
}

public void onRightSwipe(){
    Log.i(logTag, "RightToLeftSwipe!");
    activity.doSomething();
}

public void onLeftSwipe(){
    Log.i(logTag, "LeftToRightSwipe!");
    activity.doSomething();
}

public void onDownSwipe(){
    Log.i(logTag, "onTopToBottomSwipe!");
    activity.doSomething();
}

public void onUpSwipe(){
    Log.i(logTag, "onBottomToTopSwipe!");
    activity.doSomething();
}

public boolean onTouch(View v, MotionEvent event) {
    switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

       // swipe horizontal?
        if(Math.abs(deltaX) > Math.abs(deltaY))
        {
            if(Math.abs(deltaX) > MIN_DISTANCE){
                // left or right
                if(deltaX > 0) { this.onRightSwipe(); return true; }
                if(deltaX < 0) { this.onLeftSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Horizontal Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }
        }
        // swipe vertical?
        else 
        {
            if(Math.abs(deltaY) > MIN_DISTANCE){
                // top or down
                if(deltaY < 0) { this.onDownSwipe(); return true; }
                if(deltaY > 0) { this.onUpSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Vertical Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }
        }

            return true;
        }
    }
    return false;
}

}

对我来说真的很好!

其他回答

有一个内置的界面,你可以直接使用所有的手势: 下面是对基本级别用户的解释: 有两个进口品在选择时要小心,因为它们都是不同的

Thomas Fankhauser和Marek Sebera提出的我的解决方案版本(不处理垂直滑动):

SwipeInterface.java

import android.view.View;

public interface SwipeInterface {

    public void onLeftToRight(View v);

    public void onRightToLeft(View v);
}

ActivitySwipeDetector.java

import android.content.Context;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;

public class ActivitySwipeDetector implements View.OnTouchListener {

    static final String logTag = "ActivitySwipeDetector";
    private SwipeInterface activity;
    private float downX, downY;
    private long timeDown;
    private final float MIN_DISTANCE;
    private final int VELOCITY;
    private final float MAX_OFF_PATH;

    public ActivitySwipeDetector(Context context, SwipeInterface activity){
        this.activity = activity;
        final ViewConfiguration vc = ViewConfiguration.get(context);
        DisplayMetrics dm = context.getResources().getDisplayMetrics();
        MIN_DISTANCE = vc.getScaledPagingTouchSlop() * dm.density;
        VELOCITY = vc.getScaledMinimumFlingVelocity();
        MAX_OFF_PATH = MIN_DISTANCE * 2;            
    }

    public void onRightToLeftSwipe(View v){
        Log.i(logTag, "RightToLeftSwipe!");
        activity.onRightToLeft(v);
    }

    public void onLeftToRightSwipe(View v){
        Log.i(logTag, "LeftToRightSwipe!");
        activity.onLeftToRight(v);
    }

    public boolean onTouch(View v, MotionEvent event) {
        switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            Log.d("onTouch", "ACTION_DOWN");
            timeDown = System.currentTimeMillis();
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            Log.d("onTouch", "ACTION_UP");
            long timeUp = System.currentTimeMillis();
            float upX = event.getX();
            float upY = event.getY();

            float deltaX = downX - upX;
            float absDeltaX = Math.abs(deltaX); 
            float deltaY = downY - upY;
            float absDeltaY = Math.abs(deltaY);

            long time = timeUp - timeDown;

            if (absDeltaY > MAX_OFF_PATH) {
                Log.i(logTag, String.format("absDeltaY=%.2f, MAX_OFF_PATH=%.2f", absDeltaY, MAX_OFF_PATH));
                return v.performClick();
            }

            final long M_SEC = 1000;
            if (absDeltaX > MIN_DISTANCE && absDeltaX > time * VELOCITY / M_SEC) {
                if(deltaX < 0) { this.onLeftToRightSwipe(v); return true; }
                if(deltaX > 0) { this.onRightToLeftSwipe(v); return true; }
            } else {
                Log.i(logTag, String.format("absDeltaX=%.2f, MIN_DISTANCE=%.2f, absDeltaX > MIN_DISTANCE=%b", absDeltaX, MIN_DISTANCE, (absDeltaX > MIN_DISTANCE)));
                Log.i(logTag, String.format("absDeltaX=%.2f, time=%d, VELOCITY=%d, time*VELOCITY/M_SEC=%d, absDeltaX > time * VELOCITY / M_SEC=%b", absDeltaX, time, VELOCITY, time * VELOCITY / M_SEC, (absDeltaX > time * VELOCITY / M_SEC)));
            }

        }
        }
        return false;
    }

}

在web(和本页)上有一些主张使用ViewConfiguration.getScaledTouchSlop()为SWIPE_MIN_DISTANCE设置一个设备缩放值。

getScaledTouchSlop()用于“滚动阈值”距离,而不是滑动距离。滚动阈值距离必须小于“页面之间的摆动”阈值距离。例如,这个函数在我的三星GS2上返回12个像素,而本页引用的示例大约是100个像素。

与API级别8 (Android 2.2, Froyo),你有getScaledPagingTouchSlop(),用于页面滑动。 在我的设备上,它返回24(像素)。所以如果你的API级别< 8,我认为“2 * getScaledTouchSlop()”应该是“标准”的滑动阈值。 但是我的小屏幕应用程序的用户告诉我,它太少了……在我的应用程序中,你可以垂直滚动,水平切换页面。有了建议的值,他们有时会改变页面,而不是滚动。

我做的有点不同,并编写了一个额外的检测器类来实现View.onTouchListener

onCreateis简单地把它添加到最低的布局,就像这样:

ActivitySwipeDetector activitySwipeDetector = new ActivitySwipeDetector(this);
lowestLayout = (RelativeLayout)this.findViewById(R.id.lowestLayout);
lowestLayout.setOnTouchListener(activitySwipeDetector);

在id。lowestLayout是id。在布局层次结构中最低的视图使用了xxx, lowestLayout被声明为RelativeLayout

然后是实际的活动滑动检测器类:

public class ActivitySwipeDetector implements View.OnTouchListener {

static final String logTag = "ActivitySwipeDetector";
private Activity activity;
static final int MIN_DISTANCE = 100;
private float downX, downY, upX, upY;

public ActivitySwipeDetector(Activity activity){
    this.activity = activity;
}

public void onRightSwipe(){
    Log.i(logTag, "RightToLeftSwipe!");
    activity.doSomething();
}

public void onLeftSwipe(){
    Log.i(logTag, "LeftToRightSwipe!");
    activity.doSomething();
}

public void onDownSwipe(){
    Log.i(logTag, "onTopToBottomSwipe!");
    activity.doSomething();
}

public void onUpSwipe(){
    Log.i(logTag, "onBottomToTopSwipe!");
    activity.doSomething();
}

public boolean onTouch(View v, MotionEvent event) {
    switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

       // swipe horizontal?
        if(Math.abs(deltaX) > Math.abs(deltaY))
        {
            if(Math.abs(deltaX) > MIN_DISTANCE){
                // left or right
                if(deltaX > 0) { this.onRightSwipe(); return true; }
                if(deltaX < 0) { this.onLeftSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Horizontal Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }
        }
        // swipe vertical?
        else 
        {
            if(Math.abs(deltaY) > MIN_DISTANCE){
                // top or down
                if(deltaY < 0) { this.onDownSwipe(); return true; }
                if(deltaY > 0) { this.onUpSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Vertical Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }
        }

            return true;
        }
    }
    return false;
}

}

对我来说真的很好!

这个问题有点老了,2011年7月谷歌发布了兼容性包,修订版3),其中包括与android1.6以上的ViewPager。在Android上,针对这个问题发布的GestureListener的答案感觉不太优雅。如果你正在寻找用于在Android Gallery中切换照片或在新的Play Market应用程序中切换视图的代码,那么它肯定是ViewPager。

以下是更多信息的链接:

http://android-developers.blogspot.com/2011/08/horizontal-view-swiping-with-viewpager.html http://mobile.tutsplus.com/tutorials/android/android-user-interface-design-horizontal-view-paging/ http://thepseudocoder.wordpress.com/2011/10/05/android-page-swiping-using-viewpager/