Question

在我的菜单屏幕中，用户必须使用其Google帐户登录才能使用我的应用程序。成功登录后，用户将进入个人资料屏幕，其中将显示其姓名，电子邮件和Gmail个人资料图片。

在我的Profile类中，在onCreate方法中，我有这段代码：

Intent dataFromMain = getIntent();
String fullName = dataFromMain.getExtras().getString("name");
String user_email = dataFromMain.getExtras().getString("email");
String profile_pic = dataFromMain.getExtras().getString("img_url");

Name.setText(fullName);
Username.setText(user_email);
Glide.with(this).load(profile_pic).into(Prof_Pic);

基本上，它从Menu类中获取数据（名称，电子邮件和个人资料图片URL），并能够使用该数据在个人资料屏幕上设置用户名称，显示其电子邮件并显示其Gmail个人资料图片。首次登录时，一切正常。

但是，我的应用程序顶部有一个导航栏。假设用户转到游戏屏幕，然后返回到个人资料屏幕。该应用程序崩溃了，这就是我得到的：

E/AndroidRuntime: FATAL EXCEPTION: main
Process: app.debata.com.debata, PID: 11783
java.lang.RuntimeException: Unable to start activity ComponentInfo{app.debata.com.debata/app.debata.com.debata.Profile}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2955)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3030)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1696)
    at android.os.Handler.dispatchMessage(Handler.java:105)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6938)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
    at app.debata.com.debata.Profile.onCreate(Profile.java:84)
    at android.app.Activity.performCreate(Activity.java:7183)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1220)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2908)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3030) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1696) 
    at android.os.Handler.dispatchMessage(Handler.java:105) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6938) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

当我尝试返回个人资料屏幕时，为什么我的应用程序崩溃了？我相信在我使用getExtras()和getString()方法的地方都会引起问题。

编辑：在菜单活动中包括显示数据发送方式的方法。

private void handleResult(GoogleSignInResult result) {
        if(result.isSuccess()) {
            GoogleSignInAccount account = result.getSignInAccount();
            String name = account.getDisplayName();
            String email = account.getEmail();
            String img_url = account.getPhotoUrl().toString();

            Intent intent = new Intent(this, Profile.class);
            intent.putExtra("name", name);
            intent.putExtra("email", email);
            intent.putExtra("img_url", img_url);

            startActivityForResult(intent, 1);
        }
    }

Answer 1

尝试一下

Intent dataFromMain = getIntent();
String fullName = dataFromMain.getStringExtra("name");
String user_email = dataFromMain.getStringExtra("email");
String profile_pic = dataFromMain.getStringExtra("img_url");

Name.setText(fullName);
Username.setText(user_email);
Glide.with(this).load(profile_pic).into(Prof_Pic);

Answer 2

首先，请先检查null个值，然后再将其发送到intent.检查日志，以获取是否所有值。

private void handleResult(GoogleSignInResult result) {
    if (result.isSuccess()) {
        GoogleSignInAccount account = result.getSignInAccount();
        String name = account.getDisplayName();
        String email = account.getEmail();
        String img_url = account.getPhotoUrl().toString();

        Log.e("my_tag", "name = " + (!TextUtils.isEmpty(name) ? name : "")); // check name is null
        Log.e("my_tag", "email = " + (!TextUtils.isEmpty(email) ? email : "")); // check email is null
        Log.e("my_tag", "img_url = " + (!TextUtils.isEmpty(img_url) ? img_url : "")); // check img_url is null

        // Check null value first and then startactivity
        if (!TextUtils.isEmpty(name) &&
                !TextUtils.isEmpty(email) &&
                !TextUtils.isEmpty(img_url)) {
            Intent intent = new Intent(this, Profile.class);
            intent.putExtra("name", name);
            intent.putExtra("email", email);
            intent.putExtra("img_url", img_url);

            startActivityForResult(intent, 1);
        } else {
            Toast.makeText(getApplicationContext(), "One of the values getting null", Toast.LENGTH_SHORT).show();
        }
    }
}

从另一个活动获取数据正在给RuntimeException

2 个答案: