java - 获得某些 Intent

Question

假设我有 4 个按钮，每个按钮都包含一个导航到一个 Activity 的 Intent 。它们都导航到一个相同的 Activity 。当我单击第一个按钮时，我希望新 Activity 显示“嗨”，当我单击第二个按钮时，我希望它显示“再见”，依此类推。我怎么做 ？这是一个简单的代码开始

public class Intentt extends Activity {
Button b1,b2,b3,b4;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_intentt);
    b1 = (Button)findViewById(R.id.button2);
    b2 = (Button)findViewById(R.id.button3);
    b3 = (Button)findViewById(R.id.button4);
    b4 = (Button)findViewById(R.id.button5);
    b1.setOnClickListener( new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i  = new Intent(Intentt.this,MainActivity.class);
            startActivity(i);
        }
    });
    b2.setOnClickListener( new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i  = new Intent(Intentt.this,MainActivity.class);
            startActivity(i);
        }
    });
    b3.setOnClickListener( new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i  = new Intent(Intentt.this,MainActivity.class);
            startActivity(i);
        }
    });
    b4.setOnClickListener( new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i  = new Intent(Intentt.this,MainActivity.class);
            startActivity(i);
        }
    });
}

Answer 1

只需通过 intent extras 或 intent extra Bundle 传递一些数据:

Intent i=new Intent(context,MainActivity.class);
i.putExtra(id, 453);
context.startActivity(i);

例子:

Button b1, b2, b3, b4;
Context context = this;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_intentt);
    b1 = (Button) findViewById(R.id.button2);
    b2 = (Button) findViewById(R.id.button3);
    b3 = (Button) findViewById(R.id.button4);
    b4 = (Button) findViewById(R.id.button5);

    b1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(context, MainActivity.class);
            i.putExtra(MainActivity.ID_ACTION, MainActivity.ACTION_1);
            startActivity(i);
        }
    });
    b2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(context, MainActivity.class);
            i.putExtra(MainActivity.ID_ACTION, MainActivity.ACTION_2);
            startActivity(i);
        }
    });
}

然后在该 Activity 中，您可以打开该值，使它们成为这样:

String id = intent.getStringExtra("id");
int id = intent.getIntExtra("id",-1);

然后使用if-elseif-else 或switch 语句根据传递的操作更改操作，这样您就可以显示您的消息

要正确接收它们，您需要将 Activity 的启动模式设置为“标准”because of this bug在 AndroidManifest.xml 中创建

public static final int ACTION_1 = 1;
public static final int ACTION_2 = 2;
public static final int ACTION_NULL = -1;
public static final String ID_ACTION = "action_id";

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

    int id = getIntent().getIntExtra(ID_ACTION, -1);

    if (id == ACTION_NULL) {
        Log.d("TAG", "id is null");
        Toast.makeText(MainActivity.this, "id is null!", Toast.LENGTH_SHORT).show();
    } else if (id == ACTION_1) {
        Log.i("TAG", "ALLOHA! from button 1");
         Toast.makeText(MainActivity.this, "Aloha from button 1!", Toast.LENGTH_LONG).show();
    } else if (id == ACTION_2) {
        Log.i("TAG", "Hello from button 2");
         Toast.makeText(MainActivity.thi,"Hello from button 2!", Toast.LENGTH_LONG).show();
    }
}