此代码无法正常工作，因为我添加了showPopup（）方法，我无法弄清楚原因。这个代码中的问题是什么？
package com.example.healthcity.activities;
import org.taptwo.android.widget.CircleFlowIndicator;
import org.taptwo.android.widget.ViewFlow;
import com.example.healthcity.R;
import com.example.healthcity.dataobjs.DemoDataAdapter;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.PopupWindow;
public class DemoViewFlowActivity extends Activity {
private ViewFlow viewFlow;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.bf_home_screen);
// viewFlow = (ViewFlow) findViewById(R.id.viewflow);
// viewFlow.setAdapter(new DemoDataAdapter(this));
// CircleFlowIndicator indic = (CircleFlowIndicator)
// findViewById(R.id.viewflowindic);
// viewFlow.setFlowIndicator(indic);
}
@Override
protected void onStart() {
super.onStart();
showPopup(DemoViewFlowActivity.this);
}
// The method that displays the popup.
private void showPopup(Activity context) {
int popupWidth = 200;
int popupHeight = 150;
// Inflate the popup_layout.xml
FrameLayout viewGroup = (FrameLayout) context.findViewById(R.id.popup);
LayoutInflater layoutInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = layoutInflater.inflate(R.layout.circle_layout, viewGroup);
// Creating the PopupWindow
PopupWindow popup = new PopupWindow(context);
popup.setContentView(layout);
popup.setWidth(popupWidth);
popup.setHeight(popupHeight);
popup.setFocusable(true);
// Some offset to align the popup a bit to the right, and a bit down,
// relative to button's position.
int OFFSET_X = 30;
int OFFSET_Y = 30;
// Displaying the popup at the specified location, + offsets.
popup.showAtLocation(layout, Gravity.NO_GRAVITY, 50, 50);
viewFlow = (ViewFlow) findViewById(R.id.viewflow);
viewFlow.setAdapter(new DemoDataAdapter(this));
CircleFlowIndicator indic = (CircleFlowIndicator)
findViewById(R.id.viewflowindic);
viewFlow.setFlowIndicator(indic);
// Getting a reference to Close button, and close the popup when
// clicked.
// Button close = (Button) layout.findViewById(R.id.close);
// close.setOnClickListener(new OnClickListener() {
//
// @Override
// public void onClick(View v) {
// popup.dismiss();
// }
// });
}
}
这是logcat的一部分，似乎出现错误：
07-23 23:34:25.960: W/dalvikvm(4048): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
07-23 23:34:25.969: E/AndroidRuntime(4048): FATAL EXCEPTION: main
07-23 23:34:25.969: E/AndroidRuntime(4048): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.healthcity/com.example.healthcity.activities.DemoViewFlowActivity}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.os.Handler.dispatchMessage(Handler.java:99)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.os.Looper.loop(Looper.java:137)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread.main(ActivityThread.java:5041)
07-23 23:34:25.969: E/AndroidRuntime(4048): at java.lang.reflect.Method.invokeNative(Native Method)
07-23 23:34:25.969: E/AndroidRuntime(4048): at java.lang.reflect.Method.invoke(Method.java:511)
07-23 23:34:25.969: E/AndroidRuntime(4048): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-23 23:34:25.969: E/AndroidRuntime(4048): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-23 23:34:25.969: E/AndroidRuntime(4048): at dalvik.system.NativeStart.main(Native Method)
07-23 23:34:25.969: E/AndroidRuntime(4048): Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.view.ViewRootImpl.setView(ViewRootImpl.java:567)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:246)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.widget.PopupWindow.invokePopup(PopupWindow.java:993)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.widget.PopupWindow.showAtLocation(PopupWindow.java:847)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.widget.PopupWindow.showAtLocation(PopupWindow.java:811)
07-23 23:34:25.969: E/AndroidRuntime(4048): at com.example.healthcity.activities.DemoViewFlowActivity.showPopup(DemoViewFlowActivity.java:81)
07-23 23:34:25.969: E/AndroidRuntime(4048): at com.example.healthcity.activities.DemoViewFlowActivity.onStart(DemoViewFlowActivity.java:54)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1164)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.Activity.performStart(Activity.java:5114)
07-23 23:34:25.969: E/AndroidRuntime(4048): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2153)
答案 0 :(得分：3)
更改您的代码：
将来自showPopup(this)的来电替换为：
new Handler().postDelayed(new Runnable() {
public void run() {
showPopup(DemoViewFlowActivity.this);
}
}, 100L);
修改1：
通常，100毫秒的延迟会在这种情况下产生奇迹。但是，即使在使用1秒延迟后看到你正在获得异常，我尝试了以下内容：
我创建了一个只包含LinearLayout的简单布局文件（例如，R.layout.simple_layout）。它的布局无关紧要。我给它一个id（比如，@ + id / llEmpty）。现在，在我的onCreate（Bundle）中，我使用setContentView(R.layout.simple_layout)设置了布局。而且，在我的onStart()中，我提出了以下内容：
@Override
protected void onStart() {
super.onStart();
findViewById(R.id.llEmpty).post(new Runnable() {
@Override
public void run() {
// method that creates and displays the popup
showList();
}
});
}
这将如何转换为您的代码：
您的布局文件R.layout.bf_home_screen可能包含RelativeLayout或LinearLayout作为父布局。使用id为父级布局android:id="@+id/some_id"。将您的onStart()方法更改为：
@Override
protected void onStart() {
super.onStart();
// Replace "some_id" with the id you use in the layout file
findViewById(R.id.some_id).post(new Runnable() {
@Override
public void run() {
showPopup(DemoViewFlowActivity.this);
}
});
}
答案 1 :(得分：0)
我能看到的唯一奇怪的事情是，在为PopupWindow扩充布局时，你使用FrameLayout和R.id.popup作为父级。没有必要，我会传递null。
答案 2 :(得分：0)
onAttachedToWindow 和 onDetachedFromWindow 是您的最佳选择。
并且不需要postDelayed（Runnable，100）。因为这100毫克不保证任何东西
<script>
$(document).ready(function () {
var newNum = 1;
cloneMe = function (el) {
var newElem = el.clone().attr('id', 'author' + newNum);
newElem.children().each(function (index, elem) {
$(elem).attr('id', $(elem).attr('id') + newNum).attr('name', $(elem).attr('name') + newNum);
});
$('#cloneb').before(newElem);
$('#delete_name' + newNum).html('<p id="rem_field"><a href="#"><span>Delete Line</span></a></p>');
newNum++;
};
$('p#rem_field').live('click', function () {
$(this).parents('div').remove();
return false;
});
</script>
<form name="submit" action="submit.php" method="GET">
<div class="author" id="author" name="author">
<div class="boxtitle" id="boxtitle" name="boxtitle" >
<input type="text" class="titleauthor" id="title" name="title">
<p class="help-block" id="help-block" name="help-block">Title</p></div>
<div class="box" id="box" name="box">
<input type="text" class="nameauthor" id="f_name" name="f_name">
<p class="help-block" id="help-block" name="help-block">First name</p></div>
<div class="box" id="box" name="box">
<input type="text" class="nameauthor" id="l_name" name="l_name">
<p class="help-block" id="help-block" name="help-block">Last name</p></div>
<div class="box" id="box" name="box">
<input type="text" class="nameauthor" id="email" name="email">
<p class="help-block" id="help-block" name="help-block">E-mail address</p></div>
<div class="checboxauthor" id="checkboxauthor" name="checboxauthor">
<input type="checkbox" id="check" name="check">
<p class="help-block" id="help-block" name="help-block">Contact</p></div>
<div class="boxbutton" id="boxbutton" name="boxbutton">
<button type="button" class="button" id="AuthorButton" onclick="cloneMe($('#author'));"/> Add author</button>
</div>
</div>
<input class="submit" type="submit" name="submit">
</form>