Question

我是Android的新手，我搜索了很多，但无法找到合适的答案。有人可以帮帮我吗？我有两个活动，活动1包含一个列表视图，活动2是一个编辑视图，我想要做的是点击列表视图上的项目后，它将转到活动2，操作数据后点击提交按钮（提交方法），它将返回列表视图，列表视图将显示更新的结果。这是我的avtivity 1代码

public class I4ComponentActivity extends AppCompatActivity {
private String quantity;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_component);

    final ArrayList<ComponentDetail> details = new ArrayList<ComponentDetail>();

    details.add(new ComponentDetail("Screen", "1"));
    details.add(new ComponentDetail("Camera", "2"));
    details.add(new ComponentDetail("Battery", "5"));
    details.add(new ComponentDetail("Change Port", "10"));
    details.add(new ComponentDetail("Speaker", "5"));
    details.add(new ComponentDetail("Power Key", "14"));
    details.add(new ComponentDetail("Screen Cable", "24"));

    ListView listView = (ListView) findViewById(R.id.component_list);
    DetailAdapter detailAdapter = new DetailAdapter(I4ComponentActivity.this, details);
    listView.setAdapter(detailAdapter);


    // Set a click listener to edit quantity when the list item is clicked on
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
            ComponentDetail cd = details.get(position);
            quantity = cd.getQuantity();
            Intent i = new Intent(I4ComponentActivity.this, Edit.class);
            //Create the bundle
            Bundle bundle = new Bundle();
            //Add your data to bundle
            bundle.putString("Item_quantity", quantity);
            //Add the bundle to the intent
            i.putExtras(bundle);
            //Fire that second activity
            startActivity(i);
        }
    });

}
}

这是活动2代码

public class Edit extends AppCompatActivity {
private int quantity;

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


    //Get the bundle
    Bundle bundle = getIntent().getExtras();
    //Extract the data…
    String Item_quantity = bundle.getString("Item_quantity");

    TextView tv = (TextView) findViewById(R.id.quantity_edit);
    tv.setText(Item_quantity);
    quantity  = Integer.parseInt(Item_quantity);
}

public void decrease(View v){

    quantity --;
    displayQuantity();
}
public void increase(View v){

    quantity ++;
    displayQuantity();
}
public void submit(View v){
    Intent i = new Intent(Edit.this, I4ComponentActivity.class);
    Bundle bundle = new Bundle();
    bundle.putString("quantity_back", ""+quantity);
    i.putExtras(bundle);
    startActivity(i);
}

public void displayQuantity(){
    TextView tv = (TextView) findViewById(R.id.quantity_edit);
    tv.setText(""+quantity);
}
}

Answer 1

使用startActivityForResult(Intent,1)

的StartActivity2

在Aty2 setResult(1,Intent)

中得到你想要的东西后

并重写onActivityResult你会得到后面的意图。

将项目添加到您的arraylist后。使用adapter.notifyDataSetChanged();刷新listview

如果你不清楚。 Google中必须包含大量信息

如何从其他活动更新ListView

1 个答案: