本文仅供参考，老师问问题翻车概不负责
作业的要求是设计一个简易的注册界面，然后实现一些乱起八糟的功能神马的...
如下图：
image.png
那就首先根据该要求写一个布局页面:
（由于编译器不同，使用Android Studio写布局文件会如下图所示）
image.png
然后便是JAVA代码：
public class MainActivity extends AppCompatActivity {
private EditText username;
private EditText password;
private EditText ensurePass;
RadioGroup Sex;
RadioButton male;
RadioButton female;
CheckBox music;
CheckBox sport;
CheckBox read;
Spinner college;
Spinner department;
Button button;
String sex;
String hobby;
private List checkBoxList = new ArrayList();
private String[] collegeName = {"计算机学院","外国语学院","机械学院"};
private int[] depatrmentName = {R.array.computer,R.array.language,R.array.machine};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StringBuffer stringBuffer = new StringBuffer();
String name = username.getText().toString();
String pass = password.getText().toString();
String surePass = ensurePass.getText().toString();
Log.e("Wugui",pass+surePass);
for (CheckBox checkbox : checkBoxList) {
if (checkbox.isChecked()){
stringBuffer.append(checkbox.getText().toString() + " ");
}
}
if (TextUtils.isEmpty(name) || TextUtils.isEmpty(pass) || TextUtils.isEmpty(surePass)){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("错误");
dialog.setMessage("请输入正确的信息");
dialog.setPositiveButton("确定",null);
dialog.show();
} else if (stringBuffer != null && "".equals(stringBuffer.toString())){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("错误");
dialog.setMessage("请选择至少一个爱好");
dialog.setPositiveButton("确定",null);
dialog.show();
}
else {
hobby = stringBuffer.toString();
showDialog();
}
}
});
Sex.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
if (checkedId == male.getId()){
sex = male.getText().toString();
} else {
sex = female.getText().toString();
}
}
});
}
private void showDialog(){
AlertDialog.Builder dialog = new AlertDialog.Builder(this);
dialog.setTitle("您的注册信息");
dialog.setMessage("姓名="+username.getText().toString()+
"\n" +"密码="+password.getText().toString()+
"\n"+"性别="+sex+
"\n"+"爱好="+hobby+
"\n"+"学院="+college.getSelectedItem().toString()+
"\n"+"系部="+department.getSelectedItem().toString());
dialog.setPositiveButton("确定",null);
dialog.show();
}
private void initView(){
username = (EditText) findViewById(R.id.userName);
password = (EditText) findViewById(R.id.password);
ensurePass = (EditText) findViewById(R.id.surePass);
Sex = (RadioGroup) findViewById(R.id.sex);
male = (RadioButton) findViewById(R.id.male);
female = (RadioButton) findViewById(R.id.female);
music = (CheckBox) findViewById(R.id.music);
sport = (CheckBox) findViewById(R.id.sport);
read = (CheckBox) findViewById(R.id.read);
checkBoxList.add(music);
checkBoxList.add(sport);
checkBoxList.add(read);
college = (Spinner) findViewById(R.id.college);
department = (Spinner) findViewById(R.id.department);
ArrayAdapter college_adapter = new ArrayAdapter(this,
android.R.layout.simple_spinner_dropdown_item,collegeName);
college.setAdapter(college_adapter);
college.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView parent, View view, int position, long id) {
ArrayAdapter city_adapter = ArrayAdapter.createFromResource(
MainActivity.this,depatrmentName[position],android.R.layout.simple_spinner_dropdown_item);
department.setAdapter(city_adapter);
}
@Override
public void onNothingSelected(AdapterView parent) {
}
});
}
}
提示：由于要实现在选择学院时，系部能自动进行联动，因此还需要在values下的strings文件夹里编写如下代码:
- 计算机科学与技术
- 软件工程
- 物联网
- 日语
- 英语
- 朝鲜语
- 汽车
- 自动化
- 德语
作业的主要目的就是使用Spinner来进行系部的联动以及对CheckBox进行遍历取值，下面列出这两个部分的CheckBox部分重要代码：
先初始化一个CheckBox的List，如下:
private List checkBoxList = new ArrayList();
然后遍历CheckBoxList:
for (CheckBox checkbox : checkBoxList) {
if (checkbox.isChecked()){
stringBuffer.append(checkbox.getText().toString() + " ");
}
}
由于List中主要存储了音乐、运动、阅读这三个选项；因此先在onCreate方法内将这三个CheckBox与布局内的控件进行绑定，之后再将这三个CheckBox添加到CheckBoxList中：
music = (CheckBox) findViewById(R.id.music);
sport = (CheckBox) findViewById(R.id.sport);
read = (CheckBox) findViewById(R.id.read);
checkBoxList.add(music);
checkBoxList.add(sport);
checkBoxList.add(read);
然后针对用户没有选择爱好就注册时编写弹出提示框的事件：
if (stringBuffer != null && "".equals(stringBuffer.toString())){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("错误");
dialog.setMessage("请选择至少一个爱好");
dialog.setPositiveButton("确定",null);
dialog.show();
}
image.png
（可以看上面发的全代码看看stringBuffer 是怎么来的）；
然后是系部联动部分的代码(在MainActivity的initView方法中可以看到)：
college = (Spinner) findViewById(R.id.college);
department = (Spinner) findViewById(R.id.department);
ArrayAdapter college_adapter = new ArrayAdapter(this,
android.R.layout.simple_spinner_dropdown_item,collegeName);
college.setAdapter(college_adapter);
college.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView parent, View view, int position, long id) {
ArrayAdapter city_adapter = ArrayAdapter.createFromResource(
MainActivity.this,depatrmentName[position],android.R.layout.simple_spinner_dropdown_item);
department.setAdapter(city_adapter);
}
@Override
public void onNothingSelected(AdapterView parent) {
}
});
其中第一个college_adapter主要将collegeName数组中的几个学院的名字放入Spinner控件中，实现了点击Spinner控件下拉展开内容可以显示几个学院；
而college这个Spinner的点击事件则根据点击到的学院名来在系部Spinner中显示对应的系部名；在city_adapter中，使用departmentName[position]来实现了根据选择的学院名展示相应的系部名这一方法。
(Tip:与数组一样，选择Spinner控件的第一个子选项时，position的值为0。)
最后就是一个单击注册之后显示注册信息的提示框咯：
我们先写一个showDialog的方法:
private void showDialog(){
AlertDialog.Builder dialog = new AlertDialog.Builder(this);
dialog.setTitle("您的注册信息");
dialog.setMessage("姓名="+username.getText().toString()+
"\n" +"密码="+password.getText().toString()+
"\n"+"性别="+sex+
"\n"+"爱好="+hobby+
"\n"+"学院="+college.getSelectedItem().toString()+
"\n"+"系部="+department.getSelectedItem().toString());
dialog.setPositiveButton("确定",null);
dialog.show();
}
然后，在注册button点击事件中进行逻辑判断，当注册信息无误是即可显示该Dialog：
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StringBuffer stringBuffer = new StringBuffer();
String name = username.getText().toString();
String pass = password.getText().toString();
String surePass = ensurePass.getText().toString();
for (CheckBox checkbox : checkBoxList) {
if (checkbox.isChecked()){
stringBuffer.append(checkbox.getText().toString() + " ");
}
}
if (TextUtils.isEmpty(name) || TextUtils.isEmpty(pass) || TextUtils.isEmpty(surePass)){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("错误");
dialog.setMessage("请输入正确的信息");
dialog.setPositiveButton("确定",null);
dialog.show();
} else if (stringBuffer != null && "".equals(stringBuffer.toString())){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("错误");
dialog.setMessage("请选择至少一个爱好");
dialog.setPositiveButton("确定",null);
dialog.show();
}
else {
hobby = stringBuffer.toString();
showDialog();
}
}
});
至此，一个简单的注册页面以及简单的判断就完成了（建议修改提供的XML源码，将password的EditText的inputType修改为password）。