我正在从数据库中填充TableLayout。我创建了一个buildTable方法来从数据库中获取数据并动态创建表行，该方法在MainActivity onCreate方法中称为该方法。一切都很好，没有错误，但是当我运行应用程序时，它没有显示带有数据的表。
这是我尝试的主要活动：
public class MainActivity extends AppCompatActivity {
private EditText userName, Password ,salary, Address, name;
private TableLayout t1;
TestDatabaseAdapter testHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
userName = (EditText) findViewById(R.id.userNameEditText);
Password = (EditText) findViewById(R.id.passwordEditText);
salary = (EditText) findViewById(R.id.salaryEditText);
Address = (EditText) findViewById(R.id.addressEditText);
name = (EditText) findViewById(R.id.searchTextView);
t1 = (TableLayout) findViewById(R.id.main_table);
testHelper = new TestDatabaseAdapter(this);
BuildTable();
}
private void BuildTable() {
Cursor mCur = testHelper.populateTable();
Message.message(this, "Successfully inserted a row at "+mCur.getCount());
if (mCur.getCount() != 0) {
if (mCur.moveToFirst()) {
do {
int rows = mCur.getCount();
int cols = mCur.getColumnCount();
// outer for loop
for (int i = 0; i < rows; i++) {
TableRow row = new TableRow(this);
TableLayout.LayoutParams tableRowParams=
new TableLayout.LayoutParams
(TableLayout.LayoutParams.MATCH_PARENT,TableLayout.LayoutParams.WRAP_CONTENT);
row.setLayoutParams(tableRowParams);
// inner for loop
for (int j = 0; j < cols; j++) {
TextView tv = new TextView(this);
tv.setLayoutParams(new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT));
tv.setGravity(Gravity.CENTER);
tv.setTextSize(18);
tv.setPadding(0, 5, 0, 5);
tv.setText(mCur.getString(j));
row.addView(tv);
}
t1.addView(row);
}
} while (mCur.moveToNext());
}
}
}
public void addUser(View view){
String user = userName.getText().toString();
String pass = Password.getText().toString();
String sal = salary.getText().toString();
String add = Address.getText().toString();
long id = testHelper.insertData(user,pass,sal,add);
if (id<0){
Message.message(this, "Unsuccessful");
}
else {
Message.message(this, "Successfully inserted a row at "+id);
}
}
public void getUserDetails(View view){
String data = testHelper.getAllData();
Message.message(this, data);
}
public void getSingleUserDetails(View view){
String s1 = name.getText().toString();
if (!(s1.isEmpty())) {
String sub1 = s1.substring(0,s1.indexOf(" "));
String sub2 = s1.substring(s1.indexOf(" ")+1);
String data = testHelper.getSingleUserDate(sub1,sub2);
if (data.isEmpty()){
Message.message(this, "No record found");
}
else {
Message.message(this, data);
}
} else {
Message.message(this, "Enter Some Text ");
}
}
public void update(View view){
String s1 = name.getText().toString();
if (!(s1.isEmpty())) {
String sub1 = s1.substring(0,s1.indexOf(" "));
String sub2 = s1.substring(s1.indexOf(" ")+1);
int data = testHelper.updateAddress(sub1, sub2);
if (data<1){
Message.message(this, "No record found");
}
else {
Message.message(this, data+ " : Rows Successfully updated ");
}
} else {
Message.message(this, "Enter Some Text ");
}
}
public void delete(View view){
String s1 = name.getText().toString();
if (!(s1.isEmpty())) {
String sub1 = s1.substring(0,s1.indexOf(" "));
String sub2 = s1.substring(s1.indexOf(" ")+1);
int data = testHelper.deletebyName(sub1, sub2);
if (data<1){
Message.message(this, "No record found");
}
else {
Message.message(this, data+ " : Rows Successfully deleted ");
}
} else {
Message.message(this, "Enter Some Text ");
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
这是我的activity_main
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:weightSum="1">
<TextView
android:id="@+id/Linealayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/userNameTextView"
android:textSize="20dp" />
<EditText
android:id="@+id/userNameEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/PassWordTextView"
android:textSize="20dp" />
<EditText
android:id="@+id/passwordEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:ems="10"
android:inputType="textPassword" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/SalaryTextView"
android:textSize="20dp" />
<EditText
android:id="@+id/salaryEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/AddressTextView"
android:textSize="20dp" />
<EditText
android:id="@+id/addressEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="addUser"
android:text="@string/AddUserButton" />
<Button
android:id="@+id/detailsButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="BuildTable"
android:text="Get User Details" />
<EditText
android:id="@+id/searchTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:hint="Enter Name of person" />
<Button
android:id="@+id/button2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:onClick="getSingleUserDetails"
android:text="Get User Salary & Address " />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Update"
android:id="@+id/button3"
android:layout_gravity="center_horizontal"
android:onClick="update" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Delete"
android:id="@+id/button4"
android:layout_gravity="center_horizontal"
android:onClick="delete" />
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/main_table"
android:background="#8cff9d2c"></TableLayout>
</LinearLayout>
</ScrollView>
类： Message.java
public class Message {
public static void message(Context context, String message){
Toast.makeText(context , message, Toast.LENGTH_LONG).show();
}
}
类：TestDatabaseAdapter.java
public class TestDatabaseAdapter {
TestHelper testHelper;
public TestDatabaseAdapter(Context context) {
testHelper = new TestHelper(context);
}
public long insertData(String name, String password, String salary, String Address) {
SQLiteDatabase db = testHelper.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(TestHelper.EMPLOYEE_NAME, name);
contentValues.put(TestHelper.EMPLOYEE_PASSWORD, password);
contentValues.put(TestHelper.EMPLOYEE_SALARY, salary);
contentValues.put(TestHelper.EMPLOYEE_ADDRESS, Address);
long id = db.insert(testHelper.TABLE_NAME, null, contentValues);
return id;
}
public Cursor populateTable(){
SQLiteDatabase db = testHelper.getReadableDatabase();
String[] columns = {TestHelper.EMPLOYEE_ID, TestHelper.EMPLOYEE_NAME, TestHelper.EMPLOYEE_PASSWORD, TestHelper.EMPLOYEE_SALARY, TestHelper.EMPLOYEE_ADDRESS};
Cursor cursor = db.query(TestHelper.TABLE_NAME, columns, null, null, null, null, null);
return cursor;
}
public String getAllData() {
SQLiteDatabase db = testHelper.getReadableDatabase();
//select * from EmployeeTable
String[] columns = {TestHelper.EMPLOYEE_ID, TestHelper.EMPLOYEE_NAME, TestHelper.EMPLOYEE_PASSWORD, TestHelper.EMPLOYEE_SALARY, TestHelper.EMPLOYEE_ADDRESS};
Cursor cursor = db.query(TestHelper.TABLE_NAME, columns, null, null, null, null, null);
StringBuffer buffer = new StringBuffer();
while (cursor.moveToNext()) {
int c1 = cursor.getColumnIndex(TestHelper.EMPLOYEE_ID);
int c2 = cursor.getColumnIndex(TestHelper.EMPLOYEE_NAME);
int c3 = cursor.getColumnIndex(TestHelper.EMPLOYEE_PASSWORD);
int c4 = cursor.getColumnIndex(TestHelper.EMPLOYEE_SALARY);
int c5 = cursor.getColumnIndex(TestHelper.EMPLOYEE_ADDRESS);
int id = cursor.getInt(c1);
String name = cursor.getString(c2);
String pass = cursor.getString(c3);
String salary = cursor.getString(c4);
String address = cursor.getString(c5);
buffer.append(id + " " + name + " " + pass + " " + salary + " " + address + "\n");
}
return buffer.toString();
}
public String getSingleUserDate(String searchName,String searchPass) {
SQLiteDatabase db = testHelper.getReadableDatabase();
//select salary & address from EmployeeTable where name = ? AND pass = ?
String[] columns = {TestHelper.EMPLOYEE_SALARY, TestHelper.EMPLOYEE_ADDRESS};
String[] selectionArgs={searchName,searchPass};
Cursor cursor = db.query(TestHelper.TABLE_NAME, columns, TestHelper.EMPLOYEE_NAME + " =? AND "+TestHelper.EMPLOYEE_PASSWORD+ " =?", selectionArgs, null, null, null, null);
StringBuffer buffer = new StringBuffer();
while (cursor.moveToNext()) {
/* int c1 = cursor.getColumnIndex(TestHelper.EMPLOYEE_ID);
int c2 = cursor.getColumnIndex(TestHelper.EMPLOYEE_NAME);
int c3 = cursor.getColumnIndex(TestHelper.EMPLOYEE_PASSWORD);*/
int c4 = cursor.getColumnIndex(TestHelper.EMPLOYEE_SALARY);
int c5 = cursor.getColumnIndex(TestHelper.EMPLOYEE_ADDRESS);
/* int id = cursor.getInt(c1);
String name = cursor.getString(c2);
String pass = cursor.getString(c3);*/
String salary = cursor.getString(c4);
String address = cursor.getString(c5);
buffer.append(/*id + " " + name + " " + pass + " " + */salary + " " + address + "\n");
}
return buffer.toString();
}
public int updateAddress(String name, String newAdd){
SQLiteDatabase db = testHelper.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(TestHelper.EMPLOYEE_ADDRESS, newAdd);
String[] whereArgs ={name};
int count = db.update(TestHelper.TABLE_NAME, contentValues, TestHelper.EMPLOYEE_NAME + " =? ", whereArgs);
return count;
}
public int deletebyName(String name,String pass){
SQLiteDatabase db = testHelper.getWritableDatabase();
String[] whereArgs = {name,pass};
int count = db.delete(TestHelper.TABLE_NAME, TestHelper.EMPLOYEE_NAME+ "= ? AND "+ TestHelper.EMPLOYEE_PASSWORD+ " =? ",whereArgs);
return count;
}
static class TestHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 17;
private static final String DATABASE_NAME = "TestDB";
private static final String TABLE_NAME = "EmployeeTable";
static final String EMPLOYEE_ID = "_id";
static final String EMPLOYEE_NAME = "Name";
static final String EMPLOYEE_PASSWORD = "Password";
static final String EMPLOYEE_SALARY = "Salary";
static final String EMPLOYEE_ADDRESS = "Address";
private Context context;
private static final String CREATE_TABLE_QUERY = "CREATE TABLE " + TABLE_NAME + " (" + EMPLOYEE_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + EMPLOYEE_NAME + " VARCHAR(255), " + EMPLOYEE_PASSWORD + " VARCHAR(255) , " + EMPLOYEE_SALARY + " INTEGER , " + EMPLOYEE_ADDRESS + " VARCHAR(255) );";
private static final String DROP_TABLE_QUERY = "DROP TABLE IF EXISTS " + TABLE_NAME;
public TestHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
Message.message(context, "Constructer Called");
}
@Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(CREATE_TABLE_QUERY);
Message.message(context, "onCreate Called");
} catch (SQLException e) {
Message.message(context, "" + e);
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
try {
db.execSQL(DROP_TABLE_QUERY);
Message.message(context, "onUpgrade Called");
onCreate(db);
} catch (SQLException e) {
Message.message(context, "" + e);
}
}
}
}
我发现我正在使用 ViewGroup.LayoutParams
TextView tv = new TextView(this);
tv.setLayoutParams(new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT));
所以我只是将上述代码更改为 TableRow.LayoutParams
TextView tv = new TextView(this);
tv.setLayoutParams(new TableRow.LayoutParams(
TableRow.LayoutParams.WRAP_CONTENT,
TableRow.LayoutParams.WRAP_CONTENT));
它就像一个魅力。
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我来说两句