Question

我尝试为我的Android应用程序创建统一Subview。但我得到了这样的错误

 E/AndroidRuntime(1750): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.duy/com.duy.MainActivity}: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.FrameLayout

这是我的Java代码

package com.duy;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.LinearLayout.LayoutParams;

import com.unity3d.player.UnityPlayer;


public class MainActivity extends Activity {

    private UnityPlayer m_UnityPlayer;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Create the UnityPlayer
        m_UnityPlayer = new UnityPlayer(this);
        int glesMode = m_UnityPlayer.getSettings().getInt("gles_mode", 1);
        boolean trueColor8888 = false;
        m_UnityPlayer.init(glesMode, trueColor8888);

        setContentView(R.layout.main);

        // Add the Unity view
        FrameLayout layout = (FrameLayout) findViewById(R.id.frameLayout2);    
        LayoutParams lp = new LayoutParams (LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
        layout.addView(m_UnityPlayer.getView(), 0, lp);
    }
}

这是我的xml文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/frameLayout2"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

</RelativeLayout>

我收到以下错误：

06-24 09:20:41.680: E/AndroidRuntime(1913): FATAL EXCEPTION: main
06-24 09:20:41.680: E/AndroidRuntime(1913): Process: com.duy, PID: 1913
06-24 09:20:41.680: E/AndroidRuntime(1913): java.lang.Error: FATAL EXCEPTION [main]
06-24 09:20:41.680: E/AndroidRuntime(1913): Unity version     : 5.1.1f1
06-24 09:20:41.680: E/AndroidRuntime(1913): Device model      : unknown Android SDK built for x86
06-24 09:20:41.680: E/AndroidRuntime(1913): Device fingerprint: generic_x86/sdk_x86/generic_x86:4.4.2/KK/999428:eng/test-keys
06-24 09:20:41.680: E/AndroidRuntime(1913): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.duy/com.duy.MainActivity}: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.FrameLayout
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.os.Handler.dispatchMessage(Handler.java:102)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.os.Looper.loop(Looper.java:136)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread.main(ActivityThread.java:5017)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at java.lang.reflect.Method.invokeNative(Native Method)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at java.lang.reflect.Method.invoke(Method.java:515)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at dalvik.system.NativeStart.main(Native Method)
06-24 09:20:41.680: E/AndroidRuntime(1913): Caused by: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.FrameLayout
06-24 09:20:41.680: E/AndroidRuntime(1913):     at com.duy.MainActivity.onCreate(MainActivity.java:30)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.Activity.performCreate(Activity.java:5231)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-24 09:20:41.680: E/AndroidRuntime(1913):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
06-24 09:20:41.680: E/AndroidRuntime(1913):     ... 11 more

我该如何解决这个问题？

Answer 1

R.id.frameLayout2不是框架布局。再看看你的XML。

这意味着行：FrameLayout layout = (FrameLayout) findViewById(R.id.frameLayout2);错误，因此您有一个ClassCastException

但如果你想拥有统一玩家视图，你可以使用：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Create the UnityPlayer
    m_UnityPlayer = new UnityPlayer(this);
    int glesMode = m_UnityPlayer.getSettings().getInt("gles_mode", 1);
    boolean trueColor8888 = false;
    m_UnityPlayer.init(glesMode, trueColor8888);

    setContentView(m_UnityPlayer.getView());
}

Answer 2

问题：
基本上你已经尝试将Framelayout强制转换为Relativelayout，在xml中你可以看到它是一个relativelayout：

(x1) -> (x2) -> (x3) -> (xi)

你不能这样做：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/frameLayout2"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

</RelativeLayout><!--Notice it says Relativelayout-->

因为它实际上是一个Relativelayout，而不是Framelayout，即使你把它称为“framelayout2＆＃39;它仍然是一个相对布局。

解决方案1：
我推荐这个，因为你最终得到了framelayout，并且更准确地遵循你的教程。将XML文件中的Relativelayout更改为framelayout，非常简单：

新XML文件：

FrameLayout layout = (FrameLayout) findViewById(R.id.frameLayout2);

这将完全解决您的问题，无需额外的步骤。

解决方案2：
您也可以更改Java中的代码以反映它是一个相对布局，但是这并不像您的教程那么多，但是很有必要。

新Java：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/frameLayout2"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

</FrameLayout><!--Notice it says FrameLayout Now.-->

这应该也可以，但是再次使它成为一个相对布局而不是一个framelayout，所以它可能会弄乱你的教程。

Java.lang.ClassCastException：android.widget.RelativeLayout无法强制转换为android.widget.FrameLayout

2 个答案: