java - PopupWindow 适用于 Android 2.1，但不适用于其他版本

Question

我尝试创建 PopupWindow 对象。现在我有以下 XML 代码:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toast_root"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/toast2_2"
        android:layout_gravity="center"
        android:clickable="true"
        android:maxWidth="270dp"
        android:textColor="#000000"
        android:textSize="18sp" />

    <ImageView
        android:id="@+id/ptr"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/toast2_1" />

</LinearLayout>

并遵循 Java 代码:

package com.izhmap.helpers;

import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.text.TextPaint;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
import android.widget.PopupWindow;
import android.widget.TextView;

import com.izhmap.map.R;

public class DynamicPopup {

    private int MAX_POPUP_WIDTH = 270;

    private PopupWindow _pw = null;
    LinearLayout _toastLayout = null;
    View _parentView = null;
    TextView _popupText = null;
    // class constructor
    public DynamicPopup(LinearLayout toastLayout, View parentView, DisplayMetrics dm) {
        MAX_POPUP_WIDTH*=dm.density;
        _toastLayout = toastLayout;

        _popupText = (TextView)_toastLayout.findViewById(R.id.text);

        _parentView = parentView;

        _pw = new PopupWindow(parentView.getContext());
        _pw.setTouchable(true);
        _pw.setWindowLayoutMode(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        _pw.setBackgroundDrawable(new BitmapDrawable());
        Log.d("DynamicPopup","st: DynamicPopup(), MAX_POPUP_WIDTH = "+MAX_POPUP_WIDTH);
    }

    public void showPopup(int x, int y, String text, ViewGroup.MarginLayoutParams mpl) {
        // Set new text to PopupWindow
        _popupText.setText(text);
        // choose the appropriate background size
        Rect bounds = getPopUpRect(text);

        int h = bounds.height();
        int w = bounds.width();

        Log.d("IzhMap","Popup: w="+w+" w = "+h);

        _toastLayout.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
        h = _toastLayout.getMeasuredHeight();
        w = _toastLayout.getMeasuredWidth();

        if((x - (w / 2)) < 0) {
            mpl.setMargins(x - 11, 0, 0, 0);
        } else {
            if((x + (w / 2)) > 10000) {
                mpl.setMargins(x + 11, 0, 0, 0);
            } else {
                mpl.setMargins(w / 2 - 11, 0, 0, 0);
            }
        }

        _pw.setContentView(_toastLayout);

        _pw.setWidth(WindowManager.LayoutParams.WRAP_CONTENT);
        _pw.setHeight(WindowManager.LayoutParams.WRAP_CONTENT);

        _pw.setClippingEnabled(true);
        Log.d("IzhMap","Popup:show x="+(x-w/2)+" y = "+y);

        if(h > 64) {
            _pw.showAtLocation(_parentView, Gravity.NO_GRAVITY, x - w / 2, y - bounds.height() - 30);
        } else {
            _pw.showAtLocation(_parentView, Gravity.NO_GRAVITY, x - w / 2, y - bounds.height() - 15);
        }
        _pw.update(_parentView, x - w/2, y - h, -1, -1);
    }

    private Rect getPopUpRect(String text) {
        Rect r = new Rect();

        TextPaint tp = _popupText.getPaint();
        float fontSize = _popupText.getTextSize();

        tp.setTextSize(fontSize);
        tp.getTextBounds(text, 0, text.length(), r);

        Log.d("IzhMap", "popUp need width: " + r.toShortString());

        int w = r.width();
        int h = r.height();

        if (w>=MAX_POPUP_WIDTH) {
            while (w>=MAX_POPUP_WIDTH) {
                w-=MAX_POPUP_WIDTH;
                h+=r.height();
            }

            r.set(0, 0, MAX_POPUP_WIDTH, h);
        }

        Log.d("IzhMap", "popUp width: " + r.toShortString());

        return r;
    }

    public void hidePopup(){
        _pw.dismiss();
    }

    public boolean isShowing() {
        return _pw.isShowing();
    }
}

如果应用程序在 Android 2.1 设备上运行，那么我可以看到这个弹出窗口。如果应用程序在 Android 4.1 或 3.2 设备上运行，那么我看不到弹出窗口。当此应用程序运行时，Android 2.3 设备没有响应。

你能帮我吗？

Answer 1

我发现了问题。当我删除以下行时:

_pw.update(_parentView, x - w/2, y - h, -1, -1);

PopupWindow 工作正常。