安卓控制元件拖動
/**
此文主要有兩大要點
1.控制元件的拖動
2.控制元件同時實現點選事件與拖動事件時的衝突處理
要點地方都有註釋
*/
public class extents Activity{/** Called when the activity is first created. */
private long startTime = 0;
private long endTime = 0;
private boolean isclick;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// 獲取螢幕的寬高
DisplayMetrics dm = getResources().getDisplayMetrics();
final int screenWidth = dm.widthPixels;
final int screenHeight = dm.heightPixels - 50;
final Button b=(Button)findViewById(R.id.btn);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
}
});
b.setOnTouchListener(new OnTouchListener(){
int lastX, lastY;
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
int ea=event.getAction();
Log.i("TAG", "Touch:"+ea);
//Toast.makeText(DraftTest.this, "位置:"+x+","+y, Toast.LENGTH_SHORT).show();
switch(ea){
case MotionEvent.ACTION_DOWN:
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
isclick = false;//當按下的時候設定isclick為false
startTime = System.currentTimeMillis();
case MotionEvent.ACTION_MOVE:
isclick = true;//當按鈕被移動的時候設定isclick為true??
int dy =(int)event.getRawY() - lastY;
int left = v.getLeft() + dx;
int top = v.getTop() + dy;
int right = v.getRight() + dx;
int bottom = v.getBottom() + dy;
/*
此處是為了防止滑出介面
*/
if(left < 0){left = 0;
right = left + v.getWidth();
}
if(right > screenWidth){
right = screenWidth;
left = right - v.getWidth();
}
if(top < 0){
top = 0;
bottom = top + v.getHeight();
}
if(bottom > screenHeight){
bottom = screenHeight;
top = bottom - v.getHeight();
}
v.layout(left, top, right, bottom);
Log.i("", "position:" + left +", " + top + ", " + right + ", " + bottom);
lastX = (int) event.getRawX();
lastY = (int) event.getRawY();
break;
case MotionEvent.ACTION_UP:
endTime = System.currentTimeMillis();
//當從點選到彈起小於半秒的時候,則判斷為點選,如果超過則不響應點選事件??
if ((endTime - startTime) > 0.1 * 1000L) {
isclick = true;
} else {
isclick = false;
}
}
return isclick;
}});
}
}