Question

我有一个项目让我的学校制作FAB和浮动标签。

问题是，列表视图中的项目没有显示，我很难确定它。

我有两个java类。 MainActivity.java 和 MyCustomAdapter.java

以下是MainActivity.java的代码

package com.example.sugara.floatingaction_mario;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.preference.DialogPreference;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private ListView myList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);




    myList = (ListView) findViewById(R.id.list);
    myList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Toast.makeText(MainActivity.this, "Row " + position + " clicked", Toast.LENGTH_SHORT).show();
        }
    });



    FloatingActionButton FAB = (FloatingActionButton) findViewById(R.id.fab);
    FAB.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showInputDialog();
        }
    });

    final ArrayList list = new ArrayList<>();

    list.add("Richard Felmon age 23");
    list.add("Nestor Mersy age 44");
    list.add("Bruto Char age 12");
    list.add("Filemon Mandela age 33");
    list.add("Sukyuu Nirasu age 39");

  //  final MainActivity adapter = new MyCustomAdapter(MainActivity.this, list);
  //  myList.setAdapter(adapter);




}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

protected void showInputDialog() {

    LayoutInflater layoutInflater = LayoutInflater.from(MainActivity.this);
    View promptView = layoutInflater.inflate(R.layout.activity_second, null);
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
    alertDialogBuilder.setView(promptView);

    alertDialogBuilder.setCancelable(false).setPositiveButton("Save", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {
            Toast.makeText(getApplicationContext(), "Data saved ", Toast.LENGTH_LONG).show();
        }
    }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    });

    AlertDialog alert = alertDialogBuilder.create();
    alert.show();
}
}

这是我的MyCustomAdapter.java

package com.example.sugara.floatingaction_mario;

import android.content.Context;
import android.os.Bundle;
import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.TextView;

import java.util.ArrayList;

public class MyCustomAdapter extends AppCompatActivity {


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

    //Displaying TextInputLayout Error
    TextInputLayout lNameLayout = (TextInputLayout) findViewById(R.id.lNameLayout);
    lNameLayout.setErrorEnabled(true);
    lNameLayout.setError("Min 2 chars required");

    //Displaying EditText Error
    EditText age = (EditText) findViewById(R.id.age);
    age.setError("Required");
}

}

我已尝试为listview制作适配器，但是当我这样做时它与

发生冲突

public class MyCustomAdapter extends AppCompatActivity {

你能帮我解决这个问题，并在列表视图上显示输入吗？

如果这令人困惑，我很抱歉，这是我第一次发布这样的问题

Answer 1

您的适配器必须扩展Android的Adapter类。尝试

public class MyCustomAdapter extends BaseAdapter {

然后实施必要的方法。

Answer 2

如果只想要ListView中的文本，则可能无法自定义适配器类。请用这个。这对你有帮助。

使用TextView（layout_list.xml）

创建布局

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
   android:padding="10dp"
    android:textSize="20sp" >
</TextView>

像这样修改MainActivity.java。

...
final ArrayList list = new ArrayList<>();
list.add("Richard Felmon age 23");
list.add("Nestor Mersy age 44");
list.add("Bruto Char age 12");
list.add("Filemon Mandela age 33");
list.add("Sukyuu Nirasu age 39");
myList.setAdapter(new ArrayAdapter<String>(this, R.layout.layout_list, list));

无法显示列表视图的项目

2 个答案: