我正在开发一个应用程序,其中我正在实现触摸事件和滑动事件,但现在我需要实现一个事件,即拖动屏幕向左或向右移动。
有什么建议吗?
有什么建议吗?
让我们分开来看:
触摸事件:
以下是一个简单的示例,演示如何检测简单的触摸事件,获取坐标并显示一个提示。
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.widget.Toast;
public class MainActivity extends Activity {
private boolean isTouch = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int X = (int) event.getX();
int Y = (int) event.getY();
int eventaction = event.getAction();
switch (eventaction) {
case MotionEvent.ACTION_DOWN:
Toast.makeText(this, "ACTION_DOWN AT COORDS "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();
isTouch = true;
break;
case MotionEvent.ACTION_MOVE:
Toast.makeText(this, "MOVE "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();
break;
case MotionEvent.ACTION_UP:
Toast.makeText(this, "ACTION_UP "+"X: "+X+" Y: "+Y, Toast.LENGTH_SHORT).show();
break;
}
return true;
}
}
如果你想实现水平滑动,可以使用以下方法
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;
int[] values = new int[] {
R.drawable.image1,
R.drawable.image2,
R.drawable.image3 };
@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;
}
/**
* left to right swipe
*/
if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
//next image
setImage(image+1);
/**
* right to left
*/
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
//prev image
setImage(image-1);
}
} catch (Exception e) {
}
return false;
}