Question

当用户点击graphic_a时，我正尝试从我的简介屏幕导航到第二个屏幕。出于某种原因，当我点击graphic_a时应用程序退出。

知道我做错了什么吗？

我在MainActivity.java中有以下代码：

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the View that shows the graphic_a
        ImageView graphic_a = findViewById(R.id.graphic_a);

        // Set a click listener on that View
        graphic_a.setOnClickListener(new View.OnClickListener() {
        // The code in this method will be executed when graphic_a is clicked on.
            @Override
            public void onClick(View view) {
                // Create a new intent to open the {@link SongAActivity}
                Intent songAIntent = new Intent(MainActivity.this, SongAActivity.class);

                // Start the new activity
                startActivity(songAIntent);
            }
        });
    } 
}

因此用户点击了graphic_a，他们应该被发送到具有以下代码的SongAActivity.class：

public class SongAActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.song_layout);


        ImageView imageView = findViewById(R.id.graphic_x);
        imageView.setImageDrawable(getResources().getDrawable(R.drawable.sgtpepper));
    }
}

还有一个xml文件：

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/tan_background"
android:orientation="vertical"
tools:context="com.example.android.musicplayer.MainActivity">

    <ImageView
        android:id="@+id/graphic_x"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
    />

</LinearLayout>

我的logcat是：

04-18 23:01:36.568 27625-27625/? I/zygote64: Late-enabling -Xcheck:jni
04-18 23:01:36.641 27625-27638/? E/zygote64: Failed sending reply to debugger: Broken pipe
04-18 23:01:36.642 27625-27638/? I/zygote64: Debugger is no longer active
04-18 23:01:36.757 27625-27625/? I/InstantRun: starting instant run server: is main process
04-18 23:01:37.141 27625-27652/? D/OpenGLRenderer: HWUI GL Pipeline
04-18 23:01:48.710 27625-27652/com.example.android.musicplayer I/Adreno: QUALCOMM build                   : 2941438, I916dfac403
    Build Date                       : 10/03/17
    OpenGL ES Shader Compiler Version: EV031.21.02.00
    Local Branch                     : O18A
    Remote Branch                    : 
    Remote Branch                    : 
    Reconstruct Branch               : 
04-18 23:01:48.716 27625-27652/com.example.android.musicplayer I/Adreno: PFP: 0x005ff087, ME: 0x005ff063
04-18 23:01:48.720 27625-27652/com.example.android.musicplayer I/zygote64: android::hardware::configstore::V1_0::ISurfaceFlingerConfigs::hasWideColorDisplay retrieved: 0
04-18 23:01:48.720 27625-27652/com.example.android.musicplayer I/OpenGLRenderer: Initialized EGL, version 1.4
04-18 23:01:48.721 27625-27652/com.example.android.musicplayer D/OpenGLRenderer: Swap behavior 2
04-18 23:01:53.009 27625-27625/com.example.android.musicplayer D/AndroidRuntime: Shutting down VM
04-18 23:01:53.016 27625-27625/com.example.android.musicplayer E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.android.musicplayer, PID: 27625
    android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.android.musicplayer/com.example.android.musicplayer.SongAActivity}; have you declared this activity in your AndroidManifest.xml?
        at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1933)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1616)
        at android.app.Activity.startActivityForResult(Activity.java:4487)
        at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:68)
        at android.app.Activity.startActivityForResult(Activity.java:4445)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:751)
        at android.app.Activity.startActivity(Activity.java:4806)
        at android.app.Activity.startActivity(Activity.java:4774)
        at com.example.android.musicplayer.MainActivity$1.onClick(MainActivity.java:31)
        at android.view.View.performClick(View.java:6294)
        at android.view.View$PerformClick.run(View.java:24770)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

Answer 1

从您的代码中，在MainActivity.java文件中，您应该更改：

// Find the View that shows the graphic_a
ImageView graphic_a = findViewById(R.id.graphic_a);

要

// Find the View that shows the graphic_a ImageView graphic_a = findViewById(R.id.graphic_x);

或者只是将xml文件中的图片ID从 graphic_x 更改为 graphic_a 。

更新2：从您的日志cat中，您尚未在清单文件中声明SongAActivity。要解决此问题，请在清单文件中添加以下代码。

<activity android:name="com.example.android.musicplayer.SongAActivity"/>

然后再试一次。

如何在Android中加载具有图像的屏幕？

1 个答案: