Drag and Drop controls

Drag and Drop controls

Yes. The position of the ImageView changes when the ImageView is moved, and the ImageView is horizontally centered when the image view is double-clicked.

 

Package com.org. demo. youku; import com.org. wangfeng. r; import android. app. activity; import android. content. sharedPreferences; import android. content. sharedPreferences. editor; import android. OS. bundle; import android. OS. systemClock; import android. view. motionEvent; import android. view. view; import android. view. view. onTouchListener; import android. widget. imageView; import android. widget. relativeLayout; import android. widget. relativeLayout. layoutParams; import android. widget. textView; public class MainDrag extends Activity {private TextView TV _top; private TextView TV _bottom; private ImageView iv_drag; // private ViewPager dPager; private int startX; private int startY; private SharedPreferences sPreferences; long [] mHits = new long [2]; // array Length indicates the number of clicks @ Override protected void onCreate (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onCreate (savedInstanceState); setContentView (R. layout. maindrag); TV _top = (TextView) findViewById (R. id. TV _top); TV _bottom = (TextView) findViewById (R. id. TV _bottom); iv_drag = (ImageView) findViewById (R. id. iv_drag); // calculate the width and height of the mobile phone screen. final int winWidth = getWindowManager (). getdefadisplay display (). getWidth (); final int winHeight = getWindowManager (). getdefadisplay display (). getHeight (); // used to record coordinates. The coordinate sPreferences = getSharedPreferences ("config", Activity. MODE_PRIVATE); int getLastX = sPreferences. getInt ("lastX", 0); int getLastY = sPreferences. getInt ("lastY", 0); // onMeasure (measurement view), onLayout (placement), onDraw (Painting) // ivDrag. layout (getLastX, getLastY, getLastX + ivDrag. getWidth (), // getLastY + ivDrag. getHeight (); // you cannot use this method. if (getLastY> winHeight/2) cannot be placed before measurement is completed, hide TV _top.setVisibility (View. VISIBLE); TV _bottom.setVisibility (View. INVISIBLE);} else {TV _top.setVisibility (View. invisibility); TV _bottom.setVisibility (View. VISIBLE);} RelativeLayout. layoutParams layoutParams = (LayoutParams) iv_drag. getLayoutParams (); layoutParams. leftMargin = getLastX; // set the left margin of layoutParams. topMargin = getLastY; // set the top margin iv_drag.setLayoutParams (layoutParams); // reset the position // set the double-click event iv_drag.setOnClickListener (new View. onClickListener () {@ Override public void onClick (View arg0) {// TODO Auto-generated method stub System. arraycopy (mHits, 1, mHits, 0, mHits. length-1); mHits [mHits. length-1] = SystemClock. uptimeMillis (); // The time after startup. if (mHits [0]> = (SystemClock. uptimeMillis ()-500) {// center the image in the System. out. println ("double-click to center"); iv_drag.layout (winWidth/2-iv_drag.getWidth ()/2, iv_drag.getTop (), winWidth/2 + iv_drag.getWidth ()/2, iv_drag.getBottom () ;}}); // sets the iv_drag.setOnTouchListener (new OnTouchListener () {@ Override public boolean onTouch (View v, MotionEvent event) {// TODO Auto-generated method stub switch (event. getAction () {case MotionEvent. ACTION_DOWN: // initialize the starting point coordinate startX = (int) event. getRawX (); startY = (int) event. getRawY (); break; case MotionEvent. ACTION_MOVE: // The Moving Coordinate int endX = (int) event. getRawX (); int endY = (int) event. getRawY (); // calculate the offset int dx = endX-startX; int dy = endY-startY; // The distance from the upper left and lower right after the update int l = iv_drag.getLeft () + dx; int t = iv_drag.getTop () + dy; int r = iv_drag.getRight () + dx; int B = iv_drag.getBottom () + dy; // determine whether the screen boundary is exceeded, note the height of the status bar if (l <0 | r> winWidth | t <0 | B> winHeight) {System. out. println ("not required"); break;} // determines whether to display and hide the if (t> winHeight/2) in the prompt Box Based on the Image Position {// display above, hide TV _top.setVisibility (View. VISIBLE); TV _bottom.setVisibility (View. INVISIBLE);} else {TV _top.setVisibility (View. invisibility); TV _bottom.setVisibility (View. VISIBLE);} // update the iv_drag.layout (l, t, r, B); // reinitialize the startX = (int) event. getRawX (); startY = (int) event. getRawY (); System. out. println ("ACTION_MOVE coordinate x" + startX + "--- iv_drag.getLeft () ---" + iv_drag.getLeft (); break; case MotionEvent. ACTION_UP: // records the coordinate System after moving. out. println ("ACTION_UP" + "iv_drag.getLeft () ---" + iv_drag.getLeft () + "--- iv_drag.getTop () ---" + iv_drag.getTop (); Editor edit = sPreferences. edit (); edit. putInt ("lastX", iv_drag.getLeft (); edit. putInt ("lastY", iv_drag.getTop (); edit. commit (); break; default: break;} return false; // event to be passed down so that onclick (double-click event) can respond }});}}

<? Xml version = "1.0" encoding = "UTF-8"?> <RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "match_parent" android: layout_height = "match_parent"> <TextView android: id = "@ + id/TV _top" android: layout_width = "match_parent" android: layout_height = "wrap_content" android: Rule = "true" android: layout_centerHorizontal = "true" android: background = "@ drawable/png_3" android: gravity = "center" android: padding = "10dp" android: text = "hold down the prompt box and drag it to any location \ n press the return key of the mobile phone to take effect immediately" android: textColor = "#000" android: textSize = "16sp"/> <TextView android: id = "@ + id/TV _bottom" android: layout_width = "match_parent" android: layout_height = "wrap_content" android: layout_alignParentBottom = "true" android: layout_centerHorizontal = "true" android: background = "@ drawable/png_3" android: gravity = "center" android: padding = "10dp" android: text = "hold down the prompt box and drag it to any location \ n press the return key of the mobile phone to take effect immediately" android: textColor = "#000" android: textSize = "16sp" android: visibility = "invisible"/> <ImageView android: id = "@ + id/iv_drag" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: layout_marginTop = "90dp" android: contentDescription = "@ null" android: src = "@ drawable/drag"/> </RelativeLayout>