本文实例为大家分享了Android实现自动吸附功能的具体代码，供大家参考，具体内容如下
1.简述
最近开发app过程中要实现拖动view后要可以自动吸附功能，所以需要自定义view来在onTouchEvent中来利用动画来实现此功能
2.功能代码部分
代码语言：javascript复制import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.animation.DecelerateInterpolator;
import android.widget.ImageView;
public class AdsorbentViews extends ImageView {
private int maxWidth;
private int maxHeight;
private int viewWidth;
private int viewHeight;
private float downx;
private float downy;
private Context mContext;
public CustomViews(Context context) {
this(context, null);
}
public CustomViews(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CustomViews(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mContext = context;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
DisplayMetrics outMetrics = new DisplayMetrics();
WindowManager windowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getRealMetrics(outMetrics);
//屏幕的宽度
maxWidth = outMetrics.widthPixels;
//屏幕的高度
maxHeight = outMetrics.heightPixels;
/**
* 控件的宽高
*/
viewWidth = canvas.getWidth();
viewHeight = canvas.getHeight();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
clearAnimation();
downx = event.getX();
downy = event.getY();
return true;
case MotionEvent.ACTION_MOVE:
float moveX = event.getRawX() - downx;
float moveY = event.getRawY() - downy;
moveX = moveX < 0 ? 0 : (moveX viewWidth maxWidth) ? (maxWidth - viewWidth) : moveX;
moveY = moveY < 0 ? 0 : (moveY viewHeight) maxHeight ? (maxHeight - viewHeight) : moveY;
this.setY(moveY);
this.setX(moveX);
return true;
case MotionEvent.ACTION_UP:
//做吸附效果
float centerX = getX() viewWidth / 2;
if (centerX maxWidth/2){
//靠右吸附
animate().setInterpolator(new DecelerateInterpolator())
.setDuration(500)
.x(maxWidth-viewWidth)
.y(maxHeight-viewHeight)
.start();
}else {
animate().setInterpolator(new DecelerateInterpolator())
.setDuration(500)
.x(0)
.y(maxHeight-viewHeight)
.start();
}
return true;
default:
return super.onTouchEvent(event);
}
}
}以上就是本文的全部内容，希望对大家的学习有所帮助。
