在阅读一些tutos后，我正在尝试构建我的第一个应用程序。我正在使用的是这一个：http://instinctcoder.com/android-studio-sqlite-database-example/
但是在他的应用程序中，这个人经历了一个中间步骤来列出sql记录。
我希望我的应用能够执行以下操作：
按钮“添加播放器”，一旦点击，将带来DisplayMessageActivity，我可以在其中保存数据库中的名称
名称的EditText，三个按钮（删除，更新，关闭） （点击删除时，我被带回MyActivity） （点击更新时，我会继续使用DisplayMessageActivity） （当点击关闭时，我被带回MyActivity））
我设法构建它，在两个作品之间导航，数据库插入效果很好。
保存名称时，我将返回第一个活动，但显示的列表未使用新添加的名称进行更新。
这是我的activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/swipe_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context="tab.sqltesting.com.myapplication.MyActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add Player"
android:id="@+id/addPlayer"
android:onClick="addPlayer" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@android:id/list"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"
android:layout_above="@+id/btnAdd" />
</LinearLayout>
这是我的activity_main.java
public class MyActivity extends ListActivity implements android.view.View.OnClickListener{
Button addPlayer;
TextView players_Id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
PlayersRepo repo = new PlayersRepo(this);
ArrayList<HashMap<String, String>> playersList = repo.getPlayersList();
if (playersList.size() != 0) {
ListView lv = getListView();
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
players_Id = (TextView) view.findViewById(R.id.players_Id);
String playersId = players_Id.getText().toString();
Intent objIndent = new Intent(getApplicationContext(), DisplayMessageActivity.class);
objIndent.putExtra("players_Id", Integer.parseInt(playersId));
startActivity(objIndent);
}
});
ListAdapter adapter = new SimpleAdapter(MyActivity.this, playersList, R.layout.list_players_view, new String[]{"id", "name"}, new int[]{R.id.players_Id, R.id.players_name});
setListAdapter(adapter);
} else {
Toast.makeText(this, "No Player!", Toast.LENGTH_SHORT).show();
}
addPlayer = (Button) findViewById(R.id.addPlayer);
addPlayer.setOnClickListener(this);
}
@Override
public void onClick(View view) {
if (view == findViewById(R.id.addPlayer)) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
startActivity(intent);
}
}
我想请求你的帮助，帮助我理解我做错了什么。
请接受我对我的误解的道歉。
非常感谢！
蝙蝠
答案 0 :(得分：1)
在添加OnResume（）方法时找到了解决方案。这是我最后的活动课程：
package tab.sqltesting.com.myapplication;
public class MyActivity extends ListActivity implements android.view.View.OnClickListener{
Button addPlayer;
TextView players_Id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
addPlayer = (Button) findViewById(R.id.addPlayer);
addPlayer.setOnClickListener(this);
}
@Override
public void onClick(View view) {
if (view == findViewById(R.id.addPlayer)) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
startActivity(intent);
}
}
@Override
public void onResume() {
super.onResume();
PlayersRepo repo = new PlayersRepo(this);
ArrayList<HashMap<String, String>> playersList = repo.getPlayersList();
if (playersList.size() != 0) {
ListView lv = getListView();
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
players_Id = (TextView) view.findViewById(R.id.players_Id);
String playersId = players_Id.getText().toString();
Intent objIndent = new Intent(getApplicationContext(), DisplayMessageActivity.class);
objIndent.putExtra("players_Id", Integer.parseInt(playersId));
startActivity(objIndent);
}
});
ListAdapter adapter = new SimpleAdapter(MyActivity.this, playersList, R.layout.list_players_view, new String[]{"id", "name"}, new int[]{R.id.players_Id, R.id.players_name});
setListAdapter(adapter);
} else {
Toast.makeText(this, "No Player!", Toast.LENGTH_SHORT).show();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.my, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
答案 1 :(得分：0)
包含LinearLayout的{{1}}的方向应为垂直
更改
ListView与
android:orientation="horizontal"
答案 2 :(得分：0)
只需在MainActivity中添加以下方法，当您输入save时，您将以垂直方式查看数据。
@Override
public void onResume(){
super.onResume();
StudentRepo repo = new StudentRepo(this);
ArrayList<HashMap<String, String>> studentsList = repo.getStudentList();
if(studentsList.size() != 0){
ListView lv = getListView();
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
student_Id = (TextView) view.findViewById(R.id.student_Id);
String valAnimalId = student_Id.getText().toString();
Intent objIndent = new Intent(getApplicationContext(),StudentDetail.class);
objIndent.putExtra("animalId", valAnimalId);
startActivity(objIndent);
}
});
ListAdapter adapter = new SimpleAdapter( MainActivity.this,studentsList, R.layout.view_student_entry, new String[] { "id","name"}, new int[] {R.id.student_Id, R.id.student_name});
setListAdapter(adapter);
}
}