java - 应用程式在 “startActivity(intent);”时当机

Question

This question already has answers here:

Unfortunately MyApp has stopped. How can I solve this?

(20个答案)


2年前关闭。




我想在“buttonn()”函数中使用的“inntent()”函数中启动一个新的Activity。该应用程序运行正常，但是当我单击按钮触发意图时，该应用程序每次都会崩溃。我尝试了不同的方法来启动意图，并更改了清单中的某些内容，但仍然无法正常工作。

这是我的MainActivity.java代码:

public class MainActivity extends AppCompatActivity {

private BottomNavigationView bottomNavigationView;
ListView list;
private TextView textView;
ImageButton floatButton;
static String category;
static String name;
Button button;

ArrayList<String> aaaa;
ArrayList<String> bbbbb;
ArrayList<String> cccc;
ArrayList<String> dddd;


ArrayList<String> display;


public static int[] pics = {R.drawable.no, R.drawable.yes};

Context context;

public void add() {


    aaaa.add("Example");
    aaaa.add("Example");
    aaaa.add("Example");

    bbbb.add("Example");
    bbbb.add("Example");
    bbbb.add("Example");

    cccc.add("Example");
    cccc.add("Example");

    dddd.add("Example");
    dddd.add("Example");
    dddd.add("Example");
    dddd.add("Example");

}

public void changeDisplay(ArrayList<String> a) {

    display.clear();

    for (int m = 0; m < a.size(); m++) {

        String ep = a.get(m);
        display.add(ep);

    }

}

public void inntent() {

    Intent intent = new Intent(context, GoalsActivity.class);
    intent.putExtra("category", category);
    intent.putExtra("name", name);

    startActivity(intent);

}

public void butonn(View view) {


    inntent();

}



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

    button = (Button)findViewById(R.id.button);

    context = this;
    category = "aaaa";
    name = "";

    aaaa = new ArrayList<String>();
    bbbb = new ArrayList<String>();
    cccc = new ArrayList<String>();
    dddd = new ArrayList<String>();
    display = new ArrayList<>();


    add();
    changeDisplay(aaaa);





    list = (ListView)findViewById(R.id.list_view);
    list.setAdapter(new CustomAdapter(this, display, pics));



    bottomNavigationView = (BottomNavigationView)findViewById(R.id.BottomaNavigationBar);

    bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            if (item.getItemId() == R.id.wg) {

                changeDisplay(aaaa);
                category = "aaaa";
                ((CustomAdapter) list.getAdapter()).notifyDataSetChanged();

            } else if (item.getItemId() == R.id.qg) {

                changeDisplay(bbbb);
                category = "bbbb";
                ((CustomAdapter) list.getAdapter()).notifyDataSetChanged();

            } else if (item.getItemId() == R.id.challenges) {

                changeDisplay(cccc);
                category = "cccc";
                ((CustomAdapter) list.getAdapter()).notifyDataSetChanged();

            } else if (item.getItemId() == R.id.more) {

                changeDisplay(dddd);
                category = "dddd";
                ((CustomAdapter) list.getAdapter()).notifyDataSetChanged();

            }

            return false;
        }
    });

    floatButton = (ImageButton)findViewById(R.id.imageButton);

    floatButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(MainActivity.this, "TEST", Toast.LENGTH_SHORT).show();
        }
    });


}

这是我的清单:

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".SplashActivity"
        android:screenOrientation="portrait"
        android:theme="@style/SplashTheme">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".MainActivity"
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".GoalsActivity"
        android:screenOrientation="portrait"></activity>
</application>

最佳答案

在onCreate方法内部给出以下代码。

button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
       Intent intent = new Intent(MainActivity.this, GoalsActivity.class);
    intent.putExtra("category", category);
    intent.putExtra("name", name);

    startActivity(intent);
}

关于java - 应用程式在 “startActivity(intent);”时当机，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48341139/

上一篇：java - Java中对象的hashcode是如何生成的？

下一篇：java - 匹配重复字符串部分时出现奇怪的 Java 正则表达式错误

Answer 1

在onCreate方法内部给出以下代码。

button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
       Intent intent = new Intent(MainActivity.this, GoalsActivity.class);
    intent.putExtra("category", category);
    intent.putExtra("name", name);

    startActivity(intent);
}