Question

我有一点问题：我有3个活动。活动ListClass.java

public class ListClass extends Activity {

......


listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            onItemClick1(parent, view, position, id);

        }

    });

}

public void onItemClick1(AdapterView<?> parent, View view, int position,
        long id) {

    String name = (String) parent.getItemAtPosition(position);
    String address = (String) listAddress.get(position);
    int status = (int) listStatus.get(position);
    double lat = (double) listLat.get(position);
    double lng = (double) listLng.get(position);
    String serialNumber = (String) listSerialNumber.get(position);

    getIntent().putExtra("name", name);
    getIntent().putExtra("address", address);
    getIntent().putExtra("status", status);
    getIntent().putExtra("latitude", lat);
    getIntent().putExtra("longitude", lng);
    getIntent().putExtra("serialNumber", serialNumber);

    startActivity(getIntent());

}

public Intent getIntent() {
    Intent intent = new Intent(ListClass.this, ClassB.class);
    return intent;
}

正如您所看到的，我在ClassB.java上使用了putExtra值：

public class ClassB extends Activity {

TextView textViewTitle;
TextView textView2;
TextView textViewInfo;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.charge_box);
    this.textViewTitle = (TextView) findViewById(R.id.charge_box__textView1);
    this.textView2 = (TextView) findViewById(R.id.charge_box__textView2);
    this.textViewInfo = (TextView) findViewById(R.id.charge_box__textView3);
    getActionBar().setDisplayHomeAsUpEnabled(true);
    Bundle bundle = getIntent().getExtras();
    String name = bundle.getString("name");
        String address = bundle.getString("address");
        int status = bundle.getInt("status");
        textViewTitle.setText(name);
        textViewInfo.setText(address + " " + status);

    }
}

太好了！但我需要从另一个MainClass.java活动启动ActivityB。

    Intent intent = new Intent(MainActivity.this,
                    ClassB.class);

            startActivity(intent);

问题是，当ClassB使用Bundle bundle = getIntent().getExtras();时，他找不到“额外”，因为MainClass的Intent与ListClass的Intent不同！我能怎么做？？我可以决定使用哪种Intent吗？ tahnk你！

编辑： @skygeek好吧我正在研究它，但是如果额外的值改变了怎么能创建一个静态变量呢？

public void onItemClick1(AdapterView<?> parent, View view, int position,
        long id) {

    String name = (String) parent.getItemAtPosition(position);
    String address = (String) listAddress.get(position);
    int status = (int) listStatus.get(position);
    double lat = (double) listLat.get(position);
    double lng = (double) listLng.get(position);
    String serialNumber = (String) listSerialNumber.get(position);

    Intent intent = new Intent(ListClass.this, ChargeBoxInfoActivity.class);
    intent.putExtra("name", name);
    intent.putExtra("address", address);
    intent.putExtra("status", status);
    intent.putExtra("latitude", lat);
    intent.putExtra("longitude", lng);
    intent.putExtra("serialNumber", serialNumber);
    startActivity(intent);
}

Answer 1

在ClassB的onCreate方法中进行检查

     if(getIntent().getExtras() != null)
     {
     // do your functionality with extras
        Bundle bundle = getIntent().getExtras();
        String name = bundle.getString("name");
        String address = bundle.getString("address");
        int status = bundle.getInt("status");
        textViewTitle.setText(name);
        textViewInfo.setText(address + " " + status);
     }

     else
      {
       // do whatever you want to do
      }

Answer 2

在第一次调用活动时创建具有静态字段意图的静态对象（检查其是否为null）。因此，下次从另一个类调用相同的活动时，请使用具有已设置意图的相同静态对象再次调用该活动，因此您将找到这些额外内容！

Answer 3

这是错误的：

getIntent().putExtra("name", name);
getIntent().putExtra("address", address);
getIntent().putExtra("status", status);
getIntent().putExtra("latitude", lat);
getIntent().putExtra("longitude", lng);
getIntent().putExtra("serialNumber", serialNumber);
startActivity(getIntent());

}

public Intent getIntent() {
Intent intent = new Intent(ListClass.this, ClassB.class);
return intent;

}

在每个函数调用getIntent（）之后创建新意图... 试试这个：

Intent intent = new Intent(ListClass.this, ClassB.class);
intent.putExtra("name", name);
intent.putExtra("address", address);
intent.putExtra("status", status);
intent.putExtra("latitude", lat);
intent.putExtra("longitude", lng);
intent.putExtra("serialNumber", serialNumber);
startActivity(intent);

Answer 4

我理解......试试这个：

try{
Bundle bundle = getIntent().getExtras();
String name = bundle.getString("name");
    String address = bundle.getString("address");
    int status = bundle.getInt("status");
    textViewTitle.setText(name);
    textViewInfo.setText(address + " " + status);
}}catch (Exception ignored) {
}

ANDROID：从2个不同的Activity（不同的Intent）开始相同的Activity

4 个答案: