4.2 控件双击事件和触摸事件同时响应

拖放视图交互与位置动态调整

最新推荐文章于 2021-11-13 10:52:30 发布

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最新推荐文章于 2021-11-13 10:52:30 发布

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分类专栏：手机安全卫士笔记

本文链接：https://blog.youkuaiyun.com/yangxingting/article/details/13162281

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本文介绍了一个利用触摸事件实现拖放视图在屏幕上的动态移动，并且通过改变视图位置来触发不同区域的提示效果的技术。具体包括初始化视图位置、设置触摸事件监听、处理触摸动作如按下、移动和抬起，以及实现双击事件的检测与响应。通过保存每次触摸操作后的坐标，可以记录用户的拖放路径并应用到下次应用启动时，增强用户体验。

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public class DragViewActivity extends Activity {

private static final String TAG = "DragViewActivity";

private ImageView iv_dragview;

private WindowManager wm;

private SharedPreferences sp;

private TextView tv_dragview;

private long firstTime;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout. activity_dragview);

sp=getSharedPreferences( "config", MODE_PRIVATE);

wm=(WindowManager) getSystemService( WINDOW_SERVICE);

iv_dragview = (ImageView) findViewById(R.id. iv_dragview);

tv_dragview =(TextView) findViewById(R.id.tv_dragview);

//当activity加载时确定Toast的位置

int left= sp.getInt( "left", 0);

int top= sp.getInt( "top", 0);

Log. i(TAG, "left:" +left);

Log. i(TAG, "top:" +top);

LayoutParams params=(LayoutParams) iv_dragview.getLayoutParams(); //获取布局参数

params. leftMargin=left;

params. topMargin=top;

iv_dragview.setLayoutParams(params); //设置view的布局

//给imageview 设置触摸事件

iv_dragview.setOnTouchListener( new OnTouchListener() {

int startX=0; //离屏幕左边距离

int startY=0;

//当触摸时

@Override

public boolean onTouch(View v, MotionEvent event) {

switch (event.getAction()) {

case MotionEvent. ACTION_DOWN: //触摸到屏幕时

startX = ( int) event.getRawX();

startY = ( int) event.getRawY();

break;

case MotionEvent. ACTION_MOVE: //滑动时

int newX = ( int) event.getRawX();

int newY = ( int) event.getRawY();

int dx = newX - startX; //变化的距离

int dy = newY - startY;

int l = iv_dragview.getLeft()+dx; //获取view对象移动后的位置

int r = iv_dragview.getRight()+dx;

int t = iv_dragview.getTop()+dy;

int b = iv_dragview.getBottom()+dy;

//判断view对象是都超出屏幕

if(l<0||t<0||r> wm.getDefaultDisplay(). ~~getWidth~~()||b> wm.getDefaultDisplay(). ~~getHeight~~()-40){

break;

}

iv_dragview.layout(l, t, r, b); //定位view对象位置

startX = ( int) event.getRawX(); //重新获取开始位置

startY = ( int) event.getRawY();

int tv_height = tv_dragview.getBottom()- tv_dragview.getTop(); //view控件的高度

//归属地提示TextView位置变化效果

if (t > wm.getDefaultDisplay(). ~~getHeight~~() / 2) {

// imageview 在下方, 设置textview 在上方

tv_dragview.layout( tv_dragview.getLeft(), 0,

tv_dragview.getRight(), tv_height);

} else {

// imageview 在上方, 设置textview 在下方

tv_dragview.layout( tv_dragview.getLeft(), wm.getDefaultDisplay(). ~~getHeight~~()- 40- tv_height, tv_dragview.getRight(),

wm.getDefaultDisplay(). ~~getHeight~~() - 40);

}

break;

case MotionEvent. ACTION_UP: //离开屏幕时

//将view对象距离屏幕左边的距离和距离屏幕上边的距离记录到 sp存储器中

int left= iv_dragview.getLeft();

int top= iv_dragview.getTop();

Editor edit = sp.edit();

edit.putInt( "left", left);

edit.putInt( "top", top);

edit.commit();

break;

}

return false;

}

});

// 设置双击事件
   iv_dragview.setOnClickListener( new OnClickListener() {
   @Override
   public void onClick(View v) {
   if ( firstClickTime > 0) {
   // 说明第二次点击
   long sencondTime = System.currentTimeMillis();
   long dTime = sencondTime - firstClickTime;
   if (dTime < 500) {
   // 双击事件.
Log. i(TAG, "双击事件..." );
   int iv_width = iv_dragview.getRight()- iv_dragview.getLeft();
   iv_dragview.layout( wm.getDefaultDisplay(). ~~getWidth~~()/ 2 -iv_width/ 2,
  iv_dragview.getTop(),
  wm.getDefaultDisplay(). ~~getWidth~~()/ 2+ iv_width/ 2,
  iv_dragview.getBottom());


Editor editor = sp.edit();
editor.putInt( "left", iv_dragview.getLeft());
editor.putInt( "top", iv_dragview.getTop());
editor.commit();
   firstClickTime = 0;
   return;
}
}
   firstClickTime = System.currentTimeMillis();
}

});

}