WindowManager- InvalidDisplayException

来源：互联网发布：ipad淘宝卖家软件编辑：程序博客网时间：2024/06/03 22:02

最近在了解Window及WindowManger,

Window表示一个窗口，是一个抽象类，具体由PhoneWindow实现。

而创建一个Window需要用到WindowManager, WindowManagerImpl,WindowManagerGlobal, ViewRootImpl等等，

最终以View的形式展现给用户。具体概念不做介绍，分享一个简单的例子及遇到的问题以及解决的办法。

解决遇到问题的过程比较重要。

最初是想在一个Activity 里通过WindowManager添加一个View，例子也是书上的

但是结果FC了，原因如下

09-14 11:11:37.755  9367  9367 E AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.XX.viewmotiontest02/com.XX.viewmotiontest02.ViewMotionTest02}: android.view.WindowManager$InvalidDisplayException: Unable to add window <a target=_blank href="mailto:android.view.ViewRootImpl$W@259f2ae">android.view.ViewRootImpl$W@259f2ae</a> -- the specified window type is not valid......09-14 11:11:37.755  9367  9367 E AndroidRuntime: Caused by:<span style="color:#ff0000;"> android.view.WindowManager$InvalidDisplayException: Unable to add window </span><a target=_blank href="mailto:android.view.ViewRootImpl$W@259f2ae"><span style="color:#ff0000;">android.view.ViewRootImpl$W@259f2ae</span></a><span style="color:#ff0000;"> -- the specified window type is not valid</span>09-14 11:11:37.755  9367  9367 E AndroidRuntime:  at android.view.ViewRootImpl.setView(ViewRootImpl.java:817)

对这种错误毫无头绪，并且是书上的例子。。

百度及谷歌了都没有类似的问题，尝试新启动一个Service, 然后在Service 里面再添加一个View，依然保持同样的错误。

准备放弃的时候，去官方API 瞄了一眼 WindowManager$InvalidDisplayException ，介绍说这个Exception是因为无法作为第二个View显示之类的。。

又看看错误是 window type not valid, 想到了每添加一个View , 都会为其设置WindowManager.LayoutParms, 其中WindowManager.LayoutParms 就有type属性。。

而看了创建LayoutParms的代码：

mLayoutParams = new WindowManager.LayoutParams(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT,                <span style="color:#ff0000;">0</span> , 0, PixelFormat.TRANSPARENT); // <span style="color:#ff0000;">w, h, type, flags, format;</span>

从API上看，LayoutParms对应上面的构造函数中， type 并没有0这个值的！！！

type: 1~99 应用Window层

type: 1000 ~1999 子Window

type: 2000~2999 系统层（最顶层）

因此type 为0 必须报错！！！！

改成 WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY，并且添加 uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"

所以，关键时候，官方API 还是很有帮助的！！！

部分代码：

package com.XX.viewmotiontest02;import android.app.Activity;import android.content.Context;import android.content.Intent;import android.graphics.PixelFormat;import android.os.Bundle;import android.util.Log;import android.view.Gravity;import android.view.View;import android.view.WindowManager;import android.widget.Button;public class ViewMotionTest02 extends Activity {    private static final String LOG_TAG = "ViewMotionTest02";    private boolean mIsUseService;    Button mStartBtn;    Button mFloatingButton;    WindowManager.LayoutParams mLayoutParams;    WindowManager mWindowManager;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        Log.d(LOG_TAG,"onCreate ");        setContentView(R.layout.activity_view_motion_test02);        mIsUseService = false; // true: Service,  false: Activity        Log.d(LOG_TAG,"mIsUseService: " + mIsUseService);        if(mIsUseService) {            mStartBtn = (Button) findViewById(R.id.startServiceBtn);            mStartBtn.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    Log.d(LOG_TAG, "onClick");                    Intent intent = new Intent(getApplicationContext(), ViewMotionService.class);                    startService(intent);                }            });        } else {            //mStartBtn.setVisibility(View.INVISIBLE);            mFloatingButton = new Button(this);            mFloatingButton.setText("Button In Activity");            mLayoutParams = new WindowManager.LayoutParams(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT,                    WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY , 0, PixelFormat.TRANSPARENT); // w, h, type, flags, format;            mLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL                    | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE                    | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED;            mLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;            mLayoutParams.x = 100;            mLayoutParams.y = 300;            mWindowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);            mWindowManager.addView(mFloatingButton,mLayoutParams);        }    }    @Override    protected void onDestroy() {        super.onDestroy();        Log.d(LOG_TAG,"onDestroy ");        if(mIsUseService) {            Intent intent = new Intent(getApplicationContext(), ViewMotionService.class);            stopService(intent);        } else{            mWindowManager.removeView(mFloatingButton);        }    }}

package com.XX.viewmotiontest02;import android.app.Service;import android.content.Context;import android.content.Intent;import android.graphics.PixelFormat;import android.os.IBinder;import android.support.annotation.Nullable;import android.util.Log;import android.view.Gravity;import android.view.WindowManager;import android.widget.Button;public class ViewMotionService extends Service {    private static final String LOG_TAG = "ViewMotionService";    Button mFloatingButton;    WindowManager.LayoutParams mLayoutParams;    WindowManager mWindowManager;    @Override    public void onCreate() {        super.onCreate();        Log.d(LOG_TAG, "onCreate" );        mFloatingButton = new Button(this);        mFloatingButton.setText("Button");        mLayoutParams = new WindowManager.LayoutParams(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT,                WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY , 0, PixelFormat.TRANSPARENT); // w, h, type, flags, format;        //mLayoutParams = new WindowManager.LayoutParams();        //mLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;        //mLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;        //mLayoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;        mLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE                | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED;        //mLayoutParams.format = PixelFormat.TRANSPARENT;        mLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;        mLayoutParams.x = 100;        mLayoutParams.y = 300;        mWindowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);        //Log.d(LOG_TAG,"onCreate  - 2 change -3  ");        mWindowManager.addView(mFloatingButton,mLayoutParams);        //Log.d(LOG_TAG,"onCreate  - 3  ");    }    @Nullable    @Override    public IBinder onBind(Intent intent) {        return null;    }    @Override    public void onDestroy() {        super.onDestroy();        Log.d(LOG_TAG, "onDestroy" );        mWindowManager.removeView(mFloatingButton);    }}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.xx.viewmotiontest02">    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:supportsRtl="true"        android:theme="@style/AppTheme">        <activity android:name=".ViewMotionTest02">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <service android:name=".ViewMotionService" >        </service>    </application>    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" >    </uses-permission></manifest>

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