"this"对应用程序子类中的onCreate方法意味着什么

Question

在下面的例子中,'this'用于初始化sinstance.

public class MyApplication extends Application
{
    public static MyApplication sinstance;

    @Override
    public void onCreate()
    {
        super.onCreate();
        sinstance=this;  
    }

据我所知,'this'指的是对象的当前实例的引用.如果我错了,请纠正我.现在考虑以下程序

public static MyApplication sinstance;

@Override
public void onCreate()
{
    super.onCreate();
    sinstance=new MyApplication();
}

new MyApplication用于实例化sinstance.那么为什么第二个程序在运行时崩溃,而第一个程序不会产生任何错误.它给出以下错误:

12-16 17:56:09.559 2156-2156/compdom.sad E/art: Throwing OutOfMemoryError "Failed to allocate a 10439248 byte allocation with 5527284 free bytes and 5MB until OOM"
12-16 17:56:09.559 2156-2156/compdom.sad E/AndroidRuntime: Error reporting crash
java.lang.OutOfMemoryError: Failed to allocate a 10439248 byte allocation with 5527284 free bytes and 5MB until OOM
   at java.lang.AbstractStringBuilder.enlargeBuffer(AbstractStringBuilder.java:95)
   at java.lang.AbstractStringBuilder.append0(AbstractStringBuilder.java:125)
   at java.lang.StringBuffer.append(StringBuffer.java:278)
   at java.io.StringWriter.write(StringWriter.java:123)
   at com.android.internal.util.FastPrintWriter.flushLocked(FastPrintWriter.java:358)
   at com.android.internal.util.FastPrintWriter.appendLocked(FastPrintWriter.java:303)
   at com.android.internal.util.FastPrintWriter.write(FastPrintWriter.java:625)
   at com.android.internal.util.FastPrintWriter.append(FastPrintWriter.java:658)
   at java.io.PrintWriter.append(PrintWriter.java:691)
   at java.io.PrintWriter.append(PrintWriter.java:31)
   at java.lang.Throwable.printStackTrace(Throwable.java:324)
   at java.lang.Throwable.printStackTrace(Throwable.java:300)
   at android.util.Log.getStackTraceString(Log.java:335)
   at com.android.internal.os.RuntimeInit.Clog_e(RuntimeInit.java:59)
   at com.android.internal.os.RuntimeInit.access$200(RuntimeInit.java:43)
   at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:85)
   at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
   at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)

Answer 1

第二个例子是创建一个永无止境的循环.每次实例化新的MyApplication时,都会运行onCreate方法,并以递归方式创建另一个版本.

将this在第一个是你的MyApplication的类的实例化的版本,你并不需要创建一个新的.