我是Android新手,正在开发一个简单的注册登录系统。每个Class中每个R出现很多相同的错误。错误是R无法解析为变量。我在这里发布Class代码之一
这是我的代码
package com.UserAccounts;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class SignUPActivity extends Activity
{
EditText editTextUserName,editTextPassword,editTextConfirmPassword;
Button btnCreateAccount;
LoginDataBaseAdapter loginDataBaseAdapter;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.signup);
// get Instance of Database Adapter
loginDataBaseAdapter=new LoginDataBaseAdapter(this);
loginDataBaseAdapter=loginDataBaseAdapter.open();
// Get Refferences of Views
editTextUserName=(EditText)findViewById(R.id.editTextUserName);
editTextPassword=(EditText)findViewById(R.id.editTextPassword);
editTextConfirmPassword=(EditText)findViewById(R.id.editTextConfirmPassword);
btnCreateAccount=(Button)findViewById(R.id.buttonCreateAccount);
btnCreateAccount.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
String userName=editTextUserName.getText().toString();
String password=editTextPassword.getText().toString();
String confirmPassword=editTextConfirmPassword.getText().toString();
// check if any of the fields are vaccant
if(userName.equals("")||password.equals("")||confirmPassword.equals(""))
{
Toast.makeText(getApplicationContext(), "Field Vaccant", Toast.LENGTH_LONG).show();
return;
}
// check if both password matches
if(!password.equals(confirmPassword))
{
Toast.makeText(getApplicationContext(), "Password does not match", Toast.LENGTH_LONG).show();
return;
}
else
{
// Save the Data in Database
loginDataBaseAdapter.insertEntry(userName, password);
Toast.makeText(getApplicationContext(), "Account Successfully Created ", Toast.LENGTH_LONG).show();
}
}
});
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
loginDataBaseAdapter.close();
}
}
最佳答案
如果您的类与清单中声明的应用程序包位于不同的包中,则需要导入应用程序的R
类。表格应为
import your_app_package_name_as_defined_in_the_manifest.R;
请注意,如果项目的任何资源文件中都有错误,则不会生成R.java文件,并且
R
类将不存在。如果是这种情况,请解决资源文件错误,并且未定义的R
类错误将消失。关于android - R无法解析为变量,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/17476311/