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Android View 拖動&插入 研究 |
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View 拖動&插入 即： 支持 拖動圖標 然後把之插入 2個View 之間 爲了降低難度 選用了若干ImageView 放入ViewGroup : vertical LinearLayout [代碼 步驟] 1. 定義佈局:main.xml ： Xml代碼 < ?xml version="1.0" encoding="utf-8"?> < LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/linear" > < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing1_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing2_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing3_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing3_b"/> < /LinearLayout> < ?xml version="1.0" encoding="utf-8"?> < LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/linear" > < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing1_b"/> < ImageButton android:layout_width="100dip" android:layout_height="100dip" android:src="@drawable/beijing2_b"/> < ImageButton android:layout_width="100dip" |
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android:layout_height="100dip"
android:src="@drawable/beijing3_b"/>
< ImageButton
android:layout_width="100dip"
android:layout_height="100dip"
android:src="@drawable/beijing3_b"/>
< /LinearLayout>
2. 變量初始化
Java代碼
lLayout = (LinearLayout)findViewById(R.id.linear);
lLayout = (LinearLayout)findViewById(R.id.linear);
3. 定義OnTouchListener 用於監聽所有動作 並註冊LinearLayour的所有View 實現爲：
Java代碼
touchListener = new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
int action = event.getAction();
int x = (int) event.getRawX();
int y = (int) event.getRawY();
switch(action){
//鼠標按下 拖拉動作開始
case MotionEvent.ACTION_DOWN:
point1 = v.getTop();
startX = (int)event.getX();
startY = y - v.getTop();
break;
//鼠標移動 拖拉動作進行中
case MotionEvent.ACTION_MOVE:
v.layout(x - startX, y - startY, x + v.getWidth()
- startX, y - startY + v.getHeight());
v.bringToFront();
v.postInvalidate();
break;
//鼠標釋放 拖拉動作結束
case MotionEvent.ACTION_UP:
point2 = v.getTop();
//計算插入位置 位於哪兩個相鄰View之間
int dest = getLocation(v);
//remove ori view, and then add view here
lLayout.removeView(v);
lLayout.addView(v, dest);
break;
}
return false;
}
};
//to listener all ImageView
for(int i=0;i< p>
ImageView iv = (ImageView)lLayout.getChildAt(i);
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if(iv !=null){
iv.setOnTouchListener(touchListener);
}
else {
//error, view is null!
}
}
touchListener = new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
int action = event.getAction();
int x = (int) event.getRawX();
int y = (int) event.getRawY();
switch(action){
//鼠標按下 拖拉動作開始
case MotionEvent.ACTION_DOWN:
point1 = v.getTop();
startX = (int)event.getX();
startY = y - v.getTop();
break;
//鼠標移動 拖拉動作進行中
case MotionEvent.ACTION_MOVE:
v.layout(x - startX, y - startY, x + v.getWidth()
- startX, y - startY + v.getHeight());
v.bringToFront();
v.postInvalidate();
break;
//鼠標釋放 拖拉動作結束
case MotionEvent.ACTION_UP:
point2 = v.getTop();
//計算插入位置 位於哪兩個相鄰View之間
int dest = getLocation(v);
//remove ori view, and then add view here
lLayout.removeView(v);
lLayout.addView(v, dest);
break;
}
return false;
}
};
//to listener all ImageView
for(int i=0;i< p>
ImageView iv = (ImageView)lLayout.getChildAt(i);
if(iv !=null){
iv.setOnTouchListener(touchListener);
}
else {
//error, view is null!
}
}
4. getLocation(View) 用於： 根據目標View 判斷待插入的位置 即：哪2個相鄰ImageView 之間 實現爲：
Java代碼
public int getLocation(View v){
for(int i=0;i< p>
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ImageView iv = (ImageView)lLayout.getChildAt(i);
ImageView iv2 = (ImageView)lLayout.getChildAt(i+1);
if(iv.getTop()< v.getTop() && iv2.getTop() > v.getTop()){
//refer delta of point1 & point2
if(point1 < point2){//drag to bottom
return i+1;
}
else {//drag to up
return i+1;
}
}
}
//otherwise return last location
return lLayout.getChildCount()-1;
}
public int getLocation(View v){
for(int i=0;i< p>
ImageView iv = (ImageView)lLayout.getChildAt(i);
ImageView iv2 = (ImageView)lLayout.getChildAt(i+1);
if(iv.getTop()< v.getTop() && iv2.getTop() > v.getTop()){
//refer delta of point1 & point2
if(point1 < point2){//drag to bottom
return i+1;
}
else {//drag to up
return i+1;
}
}
}
//otherwise return last location
return lLayout.getChildCount()-1;
}
5. emulator
運行截圖：
- 拖拉前：
- 拖拉後：