我遇到了一个错误,让我很烦恼,因为它只在某些情况下发生,但我真的不知道什么时候会发生,也许有更专业的人可以帮助我:
从Google教程中,我学习了制作应用内购买的代码,简要地说,这段代码做了以下事情:
1. 初始化应用内服务。 2. 检索对象的价格。 3. 如果用户点击“购买”按钮,则启动应用内购买。
现在,在我所做的所有测试中,这个功能都正常工作(使用了多台设备和API),但我收到了大量报告,说:在mHelper上抛出了NullPointerException。
我认为这是在onDestroy()方法中发生的,当服务被销毁时,但我不确定,并且我无法解决它(完整的错误日志在最后)。
以下是我尽可能清理并注释的代码:
从Google教程中,我学习了制作应用内购买的代码,简要地说,这段代码做了以下事情:
1. 初始化应用内服务。 2. 检索对象的价格。 3. 如果用户点击“购买”按钮,则启动应用内购买。
现在,在我所做的所有测试中,这个功能都正常工作(使用了多台设备和API),但我收到了大量报告,说:在mHelper上抛出了NullPointerException。
我认为这是在onDestroy()方法中发生的,当服务被销毁时,但我不确定,并且我无法解决它(完整的错误日志在最后)。
以下是我尽可能清理并注释的代码:
IabHelper mHelper;
IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener;
Activity c;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_room);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
c=this;
//Initialize the In-App Service
mHelper = new IabHelper(this, "my_key");
mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
public void onIabSetupFinished(IabResult result) {
if (!result.isSuccess()) {
//Problem setting up In-app Billing
return;
}
if (mHelper == null) return;
//Ask for the price
List additionalSkuList = new ArrayList();
additionalSkuList.add("SKU_ID");
try {
mHelper.queryInventoryAsync(true, additionalSkuList, mQueryFinishedListener);
}catch (Exception e){
//Fail while asking the price
}
}
});
//Buy Button Listener
b_buy.setOnClickListener(new View.OnClickListener()
{
public void onClick(View V)
{
try {
String payload= "my_payload"
mHelper.launchPurchaseFlow(c, "SKU_ID",1111,mPurchaseFinishedListener, payload);
} catch (Exception e) {
//Error launching purchase flow. Another async operation in progress
}
}
});
// Callback for when a purchase is finished
mPurchaseFinishedListener = new IabHelper.OnIabPurchaseFinishedListener() {
public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
// if we were disposed of in the meantime, quit.
if (mHelper == null) return;
if (result.isFailure()) {
//Error while buying
return;
}
if (purchase.getSku().equals("SKU_ID")) {
// bought the premium upgrade!
}
}
};
}
//For retrieve the price:
IabHelper.QueryInventoryFinishedListener mQueryFinishedListener = new IabHelper.QueryInventoryFinishedListener() {
public void onQueryInventoryFinished(IabResult result, Inventory inventory) {
if (result.isFailure()) {
return;
}
String z = inventory.getSkuDetails("SKU_ID").getPrice();
//The price of the object is + z !!!
}
};
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (mHelper == null) return;
// Pass on the activity result to the helper for handling
if (!mHelper.handleActivityResult(requestCode, resultCode, data)) {
super.onActivityResult(requestCode, resultCode, data);
}
}
@Override
public void onDestroy() {
super.onDestroy();
if (mHelper != null) mHelper.dispose();
mHelper = null;
}
@Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
}
以下是错误信息:
Exception java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
com.myproj.util.IabHelper.startSetup (IabHelper.java)
__null__.dispose (IabHelper.java)
__null__.launchPurchaseFlow (IabHelper.java)
__null__.handleActivityResult (IabHelper.java)
__null__.queryInventory (IabHelper.java)
__null__.queryInventoryAsync (IabHelper.java)
__null__.getResponseDesc (IabHelper.java)
__null__.checkSetupDone (IabHelper.java)
__null__.getResponseCodeFromBundle (IabHelper.java)
__null__.getResponseCodeFromIntent (IabHelper.java)
__null__.queryPurchases (IabHelper.java)
__null__.querySkuDetails (IabHelper.java)
com.myproj.util.IabHelper.startSetup (IabHelper.java)
__null__.dispose (IabHelper.java)
__null__.launchPurchaseFlow (IabHelper.java)
__null__.handleActivityResult (IabHelper.java)
__null__.queryInventory (IabHelper.java)
__null__.queryInventoryAsync (IabHelper.java)
__null__.getResponseDesc (IabHelper.java)
__null__.checkSetupDone (IabHelper.java)
__null__.getResponseCodeFromBundle (IabHelper.java)
__null__.getResponseCodeFromIntent (IabHelper.java)
__null__.queryPurchases (IabHelper.java)
__null__.querySkuDetails (IabHelper.java)
com.myproj.util.IabHelper.startSetup (IabHelper.java)
__null__.dispose (IabHelper.java)
__null__.launchPurchaseFlow (IabHelper.java)
__null__.handleActivityResult (IabHelper.java)
__null__.queryInventory (IabHelper.java)
__null__.queryInventoryAsync (IabHelper.java)
__null__.getResponseDesc (IabHelper.java)
__null__.checkSetupDone (IabHelper.java)
__null__.getResponseCodeFromBundle (IabHelper.java)
__null__.getResponseCodeFromIntent (IabHelper.java)
__null__.queryPurchases (IabHelper.java)
__null__.querySkuDetails (IabHelper.java)
com.myproj.util.IabHelper$2.run (IabHelper.java)
java.lang.Thread.run (Thread.java:818)
这里是Google IabHelper类的一些复杂方法(可能你不需要阅读此内容),它们只是在错误日志中提到并由Google编写:
Dispose:
public void dispose() {
logDebug("Disposing.");
mSetupDone = false;
if (mServiceConn != null) {
logDebug("Unbinding from service.");
if (mContext != null) mContext.unbindService(mServiceConn);
}
mDisposed = true;
mContext = null;
mServiceConn = null;
mService = null;
mPurchaseListener = null;
}
开始设置:
public void startSetup(final OnIabSetupFinishedListener listener) {
// If already set up, can't do it again.
checkNotDisposed();
if (mSetupDone) throw new IllegalStateException("IAB helper is already set up.");
// Connection to IAB service
logDebug("Starting in-app billing setup.");
mServiceConn = new ServiceConnection() {
@Override
public void onServiceDisconnected(ComponentName name) {
logDebug("Billing service disconnected.");
mService = null;
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
if (mDisposed) return;
logDebug("Billing service connected.");
mService = IInAppBillingService.Stub.asInterface(service);
String packageName = mContext.getPackageName();
try {
logDebug("Checking for in-app billing 3 support.");
// check for in-app billing v3 support
int response = mService.isBillingSupported(3, packageName, ITEM_TYPE_INAPP);
if (response != BILLING_RESPONSE_RESULT_OK) {
if (listener != null) listener.onIabSetupFinished(new IabResult(response,
"Error checking for billing v3 support."));
// if in-app purchases aren't supported, neither are subscriptions.
mSubscriptionsSupported = false;
return;
}
logDebug("In-app billing version 3 supported for " + packageName);
// check for v3 subscriptions support
response = mService.isBillingSupported(3, packageName, ITEM_TYPE_SUBS);
if (response == BILLING_RESPONSE_RESULT_OK) {
logDebug("Subscriptions AVAILABLE.");
mSubscriptionsSupported = true;
}
else {
logDebug("Subscriptions NOT AVAILABLE. Response: " + response);
}
mSetupDone = true;
}
catch (RemoteException e) {
if (listener != null) {
listener.onIabSetupFinished(new IabResult(IABHELPER_REMOTE_EXCEPTION,
"RemoteException while setting up in-app billing."));
}
e.printStackTrace();
return;
}
if (listener != null) {
listener.onIabSetupFinished(new IabResult(BILLING_RESPONSE_RESULT_OK, "Setup successful."));
}
}
};
Intent serviceIntent = new Intent("com.android.vending.billing.InAppBillingService.BIND");
serviceIntent.setPackage("com.android.vending");
if (!mContext.getPackageManager().queryIntentServices(serviceIntent, 0).isEmpty()) {
// service available to handle that Intent
mContext.bindService(serviceIntent, mServiceConn, Context.BIND_AUTO_CREATE);
}
else {
// no service available to handle that Intent
if (listener != null) {
listener.onIabSetupFinished(
new IabResult(BILLING_RESPONSE_RESULT_BILLING_UNAVAILABLE,
"Billing service unavailable on device."));
}
}
}
以及IabHelper的构造函数:
public IabHelper(Context ctx, String base64PublicKey) {
mContext = ctx.getApplicationContext();
mSignatureBase64 = base64PublicKey;
logDebug("IAB helper created.");
}
这里 是完整的 IabHelper 类。
总结:
请告诉我你是否能看到 变量 mHelper
的 NullPointerException
在何时/何处被抛出。 我从代码和虚拟/物理设备测试中都无法看出,因为它们都正常工作。
我非常确定错误是在 Activity 关闭后抛出的,但我不知道如何修复它。
如果需要更多信息,请写下来。谢谢大家!
mHelper
的使用会抛出 NPE 异常吗? - user1079425