Question

我已经编写了以下代码，现在在启动程序并单击＆＃39; Grammer＆＃34;按钮程序停止。这是我的主要活动＆＃39;。

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Button grammerButton = (Button)findViewById(R.id.grammar);

        grammerButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                Intent intent = new Intent(MainActivity.this, Grammer.class);
                startActivity(intent);
            }

        });

    } 

}

logcat将错误指向startActivity(intent); 我无奈地想弄清楚错误。

我发布了logcat错误

  02-26 23:33:26.991: D/AndroidRuntime(4604): Shutting down VM
02-26 23:33:26.991: W/dalvikvm(4604): threadid=1: thread exiting with uncaught exception (group=0x40015560)
02-26 23:33:27.011: E/AndroidRuntime(4604): FATAL EXCEPTION: main
02-26 23:33:27.011: E/AndroidRuntime(4604): android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.grammer/com.example.grammer.Grammer}; have you declared this activity in your AndroidManifest.xml?
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1405)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.app.Instrumentation.execStartActivity(Instrumentation.java:1379)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.app.Activity.startActivityForResult(Activity.java:2827)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.app.Activity.startActivity(Activity.java:2933)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at com.example.grammer.MainActivity$1.onClick(MainActivity.java:31)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.view.View.performClick(View.java:2485)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.view.View$PerformClick.run(View.java:9080)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.os.Handler.handleCallback(Handler.java:587)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.os.Looper.loop(Looper.java:123)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at android.app.ActivityThread.main(ActivityThread.java:3683)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at java.lang.reflect.Method.invokeNative(Native Method)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at java.lang.reflect.Method.invoke(Method.java:507)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-26 23:33:27.011: E/AndroidRuntime(4604):     at dalvik.system.NativeStart.main(Native Method)

这是我的manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.grammer"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.grammer.MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.example.grammer.grammar.Grammer"
            android:label="@string/title_activity_grammer" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.example.grammer.MainActivity" />
        </activity>
        <activity
           android:name="com.example.grammer.grammar.GrammarRegularActivityActivity"
            android:label="@string/title_activity_grammar_regular" >
        </activity>
        <activity
          android:name="com.example.grammer.grammar.Grammer_regular_page2er_regular_page2"
            android:label="@string/title_activity_grammer_regular_page2" >
        </activity>
        <activity
  android:name="com.example.grammer.grammar.Exerciseexample.grammer.Exercise"
            android:label="@string/title_activity_exercise" >
        </activity>
        <activity
           android:name="com.example.grammer.grammar.Amisare2Amisare2"
            android:label="@string/title_activity_amisare2" >
        </activity>
    </application>

</manifest>

Answer 1

您的清单中的这一行看起来很可疑，因为它与MainActivity不匹配相同的包（在路径中有一个额外的“.grammar”）

改变这个：

android:name="com.example.grammer.grammar.Grammer"

对此：

android:name="com.example.grammer.Grammer"

或者只是

android:name=".Grammer"

Answer 2

OnClickListener中的'startActivity（...）'方法调用应该读取MainActivity.this.startActivity（...）。

请记住，监听器中的执行上下文是监听器而不是活动（监听器中的“this”指的是监听器，而不是活动）。

Android程序无法启动

2 个答案: