我想将一些线性布局添加到现有的线性布局中。
Activity 的 xml 如下所示：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/popupLinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorPopUp"
android:gravity="center"
android:orientation="vertical" >
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="none" >
<LinearLayout
android:id="@+id/ll_horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
</LinearLayout>
</HorizontalScrollView>
</LinearLayout>
活动代码：
public class MainActivity extends Activity {
private Point p;
private PopupWindow popup;
private LinearLayout myLInearLayout;
private TextView valueTV;
private Button valueB;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button popUpButton = (Button) findViewById(R.id.open);
popUpButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (p != null)
showPopup(MainActivity.this, p);
}
});
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
int[] location = new int[2];
Button button = (Button) findViewById(R.id.open);
button.getLocationOnScreen(location);
// Initialize the Point with x, and y positions
p = new Point();
p.x = location[0];
p.y = location[1];
}
// The method that displays the popup.
private void showPopup(final Activity context, Point p) {
Rect rectgle = new Rect();
Window window = getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
int popupWidth = this.getResources().getDisplayMetrics().widthPixels;
int popupHeight = this.getResources().getDisplayMetrics().heightPixels / 4;
// Inflate the popup_layout.xml
LinearLayout viewGroup = (LinearLayout) context
.findViewById(R.id.popupLinearLayout);
LayoutInflater layoutInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = layoutInflater.inflate(R.layout.popup_layout, viewGroup);
// Creating the PopupWindow
popup = new PopupWindow(context);
popup.setContentView(layout);
popup.setWidth(popupWidth);
popup.setHeight(popupHeight);
popup.setOutsideTouchable(true);
popup.setFocusable(true);
popup.setAnimationStyle(R.style.PopupWindowAnimation);
// Some offset to align the popup a bit to the right, and a bit down,
// relative to button's position.
int OFFSET_X = 0;
int OFFSET_Y = 0;
// Clear the default translucent background
popup.setBackgroundDrawable(new BitmapDrawable());
// Displaying the popup at the specified location, + offsets.
popup.showAtLocation(layout, Gravity.NO_GRAVITY, p.x + OFFSET_X, p.y
+ OFFSET_Y);
// add LInearLayout
myLInearLayout = (LinearLayout) findViewById(R.id.ll_horizontal);
// add LayoutParams
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.MATCH_PARENT);
myLInearLayout.setOrientation(LinearLayout.HORIZONTAL);
// add textView
valueTV = new TextView(this);
valueTV.setText("The developer world is yours");
valueTV.setId(5);
valueTV.setLayoutParams(params);
// add Button
valueB = new Button(this);
valueB.setText("thedeveloperworldisyours");
valueB.setId(5);
// add the textView and the Button to LinearLayout
myLInearLayout.addView(valueTV);
myLInearLayout.addView(valueB);
}
@Override
public void onBackPressed() {
if (popup != null && popup.isShowing()) {
popup.dismiss();
popup = null;
} else {
super.onBackPressed();
}
}
如您所见，我想在为 View 充气并在 PopupWindow 中用动画显示它之后添加一个 Button 和一个 TextView。我想在 ScrollView 内的 LinearLayout 中添加一些视图。这是出于测试目的，稍后我想将完整的 LinearLayouts 添加到 ScrollView 内的 LinearLayout。动画完美运行。我只是不能以编程方式添加一些视图。我得到的一切都是我尝试添加视图的行中的 NullPointerException。
我感谢您的帮助。