应用程序因 ActivityNotFoundException 而崩溃

Question

我对下一个活动有一些问题 - 我做了一个按钮，当你点击它的时候，一个intent正在生成，然后你startActivity()这个intent。

我声明了源类和目标类。每次我单击该按钮时，它都会关闭应用程序并显示“不幸的是，我的第一个应用程序已停止”。有什么帮助吗？ 提前致谢。

package com.myfirstapplication.owner.myfirstapplication;

import android.content.Intent;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Button nextAc;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        nextAc = (Button) findViewById(R.id.nextPageButton);

        nextAc.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, SecondActivity.class);

                Bundle fromMain = new Bundle();
                fromMain.putString("BundleInfo","Look at that.");

                i.putExtras(fromMain);
                startActivity(i);

            }
        });

    }
}

日志：

06-15 12:10:03.673 2389-2389/com.myfirstapplication.owner.myfirstapplication E/AndroidRuntime: FATAL EXCEPTION: main
   Process: com.myfirstapplication.owner.myfirstapplication, PID: 2389
   android.content.ActivityNotFoundException: Unable to find explicit activity class {com.myfirstapplication.owner.myfirstapplication/com.myfirstapplication.owner.myfirstapplication.SecondActivity}; have you declared this activity in your AndroidManifest.xml?
       at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1794)
       at android.app.Instrumentation.execStartActivity(Instrumentation.java:1512)
       at android.app.Activity.startActivityForResult(Activity.java:3917)
       at android.app.Activity.startActivityForResult(Activity.java:3877)
       at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:842)
       at android.app.Activity.startActivity(Activity.java:4200)
       at android.app.Activity.startActivity(Activity.java:4168)
       at com.myfirstapplication.owner.myfirstapplication.MainActivity$1.onClick(MainActivity.java:76)
       at android.view.View.performClick(View.java:5198)
       at android.view.View$PerformClick.run(View.java:21147)
       at android.os.Handler.handleCallback(Handler.java:739)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:148)
       at android.app.ActivityThread.main(ActivityThread.java:5417)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
06-15 12:10:06.361 2389-2389/com.myfirstapplication.owner.myfirstapplication I/Process: Sending signal. PID: 2389 SIG: 9

第二个活动：

package com.myfirstapplication.owner.myfirstapplication;


import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;


public class SecondActivity extends AppCompatActivity {

    TextView tv;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_activity);

        TextView tv = (TextView)findViewById(R.id.tvID);

        Bundle fromMain = getIntent().getExtras();
        tv.setText(fromMain.getString("BundleInfo"));
    }

}

Answer 1

在清单文件中声明您的 SecondActivity。

 <application>
 <activity android:name=".SecondActivity" />
 </application>

Answer 2

我想你忘了在 Manifest.xml 中声明你的活动

只需在 Manifest 中标记您的 Activity 类，即可解决您的问题 :)

Answer 3

如果您忘记在清单文件中添加活动，将发生以下异常：

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.myfirstapplication.owner.myfirstapplication/com.myfirstapplication.owner.myfirstapplication.SecondActivity}; have you declared this activity in your AndroidManifest.xml?

要向清单文件添加新的活动，只需写以下行：

<activity android:name=".SecondActivity"/> // if your activity is in main package

或

<activity android:name="com.myfirstapplication.owner.myfirstapplication.SecondActivity"/> // if your activity is any other package.

Activity 将被添加到您的标签之间。

请记住，我不会在您的活动中添加任何操作或模式。如果您对自己的活动有特定的操作，可以在此处提供。

编码愉快！！！

Answer 4

在清单文件中声明活动

 <activity
        android:name=".secondActivity"
        />

在应用标签下