3.9

标签：findViewById private student import android id 3.9

所花时间：五十分钟左右，不到一个小时，今天主要是敲代码了，视频基本跳着看的

代码量：增部分的后四十行，删的37行，改的65行

了解到的知识点：

增代码

package com.example.test3_6;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.Toast;

import com.example.sqlitetest271.bean.Student;
import com.example.sqlitetest271.util.ToastUtil;

public class InsertActivity extends AppCompatActivity {

private EditText etName,etNumber,etScore;
private RadioButton rbMan,rbWoman;


private MySQLiteOpenHelper mMySQLiteOpenHelper;

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

initView();
mMySQLiteOpenHelper = new MySQLiteOpenHelper(this);

}

private void initView() {
etName = findViewById(R.id.et_name);
etNumber = findViewById(R.id.et_number);
etScore = findViewById(R.id.et_score);
rbMan = findViewById(R.id.rb_man);
rbWoman = findViewById(R.id.rb_woman);

}

public void insert(View view) {
String name = etName.getText().toString().trim();
String number = etNumber.getText().toString().trim();
String score = etScore.getText().toString().trim();
String gender = "";

if (rbMan.isChecked()) {
gender = "男";
}

if (rbWoman.isChecked()) {
gender = "女";
}

Student student = new Student();
student.setName(name);
student.setNumber(number);
student.setGender(gender);
student.setScore(score);

// 插入数据库中
long rowId = mMySQLiteOpenHelper.insertData(student);
if (rowId != -1) {
ToastUtil.toastShort(this, "添加成功！");
} else {
ToastUtil.toastShort(this, "添加失败！");
}

}
} 删代码 package com.example.test3_6;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import com.example.sqlitetest271.util.ToastUtil;

public class DeleteActivity extends AppCompatActivity {

private EditText etName;
private MySQLiteOpenHelper mMySQLiteOpenHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_delete);
etName = findViewById(R.id.et_name);
mMySQLiteOpenHelper = new MySQLiteOpenHelper(this);
}

public void delete(View view) {

String name = etName.getText().toString().trim();

// 按姓名从数据库中删除

int row = mMySQLiteOpenHelper.deleteFromDbByName(name);
if (row > 0) {
ToastUtil.toastLong(this, "删除成功,删了" + row + "条数据");
}else{
ToastUtil.toastLong(this, "删除失败,没有找到符合条件的数据");
}
}
} 改代码 package com.example.test3_6;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.RadioButton;

import com.example.sqlitetest271.bean.Student;
import com.example.sqlitetest271.util.ToastUtil;

public class UpdateActivity extends AppCompatActivity {
private EditText etName,etNumber,etScore;
private RadioButton rbMan,rbWoman;


private MySQLiteOpenHelper mMySQLiteOpenHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_update);
initView();
mMySQLiteOpenHelper = new MySQLiteOpenHelper(this);
}


private void initView() {
etName = findViewById(R.id.et_name);
etNumber = findViewById(R.id.et_number);
etScore = findViewById(R.id.et_score);
rbMan = findViewById(R.id.rb_man);
rbWoman = findViewById(R.id.rb_woman);

}

public void update(View view) {
String name = etName.getText().toString().trim();
String number = etNumber.getText().toString().trim();
String score = etScore.getText().toString().trim();
String gender = "";

if (rbMan.isChecked()) {
gender = "男";
}

if (rbWoman.isChecked()) {
gender = "女";
}

Student student = new Student();
student.setName(name);
student.setNumber(number);
student.setGender(gender);
student.setScore(score);

// 更新数据库
long rowId = mMySQLiteOpenHelper.updateData(student);
if (rowId > 0) {
ToastUtil.toastShort(this, "更新成功！");
} else {
ToastUtil.toastShort(this, "没有数据被更新！");
}
}
}

标签：findViewById,private,student,import,android,id,3.9
From： https://www.cnblogs.com/szm123/p/18256754