Question

我做了简单的申请。我添加了新类TouchView：

package com.example.lookatme;

import android.content.Context;
import android.view.SurfaceView;

public class TouchView extends SurfaceView{

    public TouchView(Context context) {
        super(context);

    }

}

...并在布局中添加了我的新视图：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rlMain"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".BlockerActivity" >    

    <com.example.lookatme.TouchView
        android:id="@+id/tvPaint"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignTop="@+id/ivCenter"
        android:layout_marginTop="14dp" />
    <ImageView
        android:id="@+id/ivCenter"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:src="@drawable/ic_launcher" android:contentDescription="TODO"/>

</RelativeLayout>

在活动中代码setContentView（R.layout.activity_blocker）上的启动崩溃应用程序。我做错了吗？ LogCat有相同的文字：

10-23 18:02:03.442: W/dalvikvm(1964): threadid=1: thread exiting with uncaught exception (group=0xb57ef4f0)
10-23 18:02:03.442: E/AndroidRuntime(1964): FATAL EXCEPTION: main
10-23 18:02:03.442: E/AndroidRuntime(1964): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lookatme/com.example.lookatme.BlockerActivity}: java.lang.ClassCastException: android.view.SurfaceView
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.os.Looper.loop(Looper.java:130)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread.main(ActivityThread.java:3683)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at java.lang.reflect.Method.invokeNative(Native Method)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at java.lang.reflect.Method.invoke(Method.java:507)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at dalvik.system.NativeStart.main(Native Method)
10-23 18:02:03.442: E/AndroidRuntime(1964): Caused by: java.lang.ClassCastException: android.view.SurfaceView
10-23 18:02:03.442: E/AndroidRuntime(1964):     at com.example.lookatme.BlockerActivity.onCreate(BlockerActivity.java:67)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
10-23 18:02:03.442: E/AndroidRuntime(1964):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
10-23 18:02:03.442: E/AndroidRuntime(1964):     ... 11 more
10-23 18:04:01.741: W/ActivityThread(2020): Application com.example.lookatme is waiting for the debugger on port 8100...

Answer 1

我确实找到了决定：对于子类，需要重载其他构造函数：使用Context和Attributes。

SurfaceView的子类崩溃了应用程序

1 个答案: