Android可拖动的ImageView

//简单实现可拖动的ImageViewimport android.annotation.TargetApi;import android.content.Context;import android.os.Build;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.widget.ImageView;/** * Created by  on 16-4-15. */public class DragImageView extends ImageView{    private final static String TAG = "DragImageView";    private int startX;    private int startY;    private int startL;//初始时左上X，相对于父容器    private int startT;//初始时左上Y    private int startR;//初始时右下X    private int startB;//初始时右下X    private int stopX;    private int stopY;    public DragImageView(Context context) {        super(context);    }    public DragImageView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @TargetApi(Build.VERSION_CODES.LOLLIPOP)    public DragImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {        super(context, attrs, defStyleAttr, defStyleRes);    }    public DragImageView(Context context, AttributeSet attrs) {        super(context, attrs);    }    @Override    public boolean onTouchEvent(MotionEvent event) {        int action = event.getAction();        switch (action){            case MotionEvent.ACTION_DOWN:                startX = (int) event.getRawX();//相对于屏幕的x坐标,getX()是相对于组件的坐标                startY = (int) event.getRawY();                startL = getLeft();                startT = getTop();                startR = getRight();                startB = getBottom();                Log.d(TAG,"x:"+startX+",rawX,"+event.getRawX()+",left:"+getLeft());                break;            case MotionEvent.ACTION_MOVE:            case MotionEvent.ACTION_UP:                stopX = (int) event.getRawX();                stopY = (int) event.getRawY();                int deltaX = stopX - startX;//拖动偏移量                int deltaY = stopY - startY;                this.moveToPosition(startL+deltaX,startT+deltaY,startR+deltaX,startB+deltaY);                stopX = (int) event.getRawX();                stopY = (int) event.getRawY();                invalidate();                break;        }        return true;    }    private void moveToPosition(int leftX,int leftY,int rightX,int bottom){        this.layout(leftX,leftY,rightX,bottom);    }}
更多相关文章

随机推荐
