Android需求之RxJava2实现表单校验(注册登录)

一. 预览效果

二. 开发需求

用户注册登录等表单校验场景下，只有账号和密码内容都不为空的情况下，按钮才可点击并实现按钮背景变化。

三. 实现

1. 依赖

// rxbinding3 内部已添加rxjava依赖
implementation "com.jakewharton.rxbinding3:rxbinding:3.0.0"

2. Rxjava操作符之combineLatest

combineLatest 操作符用来将多个Observable发射的数据组装起来然后在发射. 通过Func类来组装多个Observable发射的数据, 等到最后一个Observable发射数据了, 然后把所有发射的数据交给Fun进行组合, 然后把组合后的数据发射出去.

3. 具体实现

话不多说，直接上代码：

kotlin ：

// 1.继承TextWatcher
class EditTextMonitor(private val mPublishSubject: PublishSubject<String>) : TextWatcher {
     
    override fun beforeTextChanged(
        s: CharSequence,
        start: Int,
        count: Int,
        after: Int
    ) {
     }

    override fun onTextChanged(
        s: CharSequence,
        start: Int,
        before: Int,
        count: Int
    ) {
     }

    override fun afterTextChanged(s: Editable) {
     
        mPublishSubject.onNext(s.toString())
    }
}

		// 处理登陆按钮是否可点击
        val mAccountSubject = PublishSubject.create<String>()
        val mPasswordSubject = PublishSubject.create<String>()
		// 	etAccount etPwd 账号和密码输入框	
		etAccount.addTextChangedListener(EditTextMonitor(mAccountSubject))
        etPwd.addTextChangedListener(EditTextMonitor(mPasswordSubject))
        Observable.combineLatest(mAccountSubject, mPasswordSubject,
            BiFunction {
      name: String, password: String ->
                val nameLen = name.length
                val passwordLen = password.length
                nameLen > 0 && passwordLen > 0
            }
        ).subscribe {
      clickFlag: Boolean ->
            // 满足以上nameLen > 0 && passwordLen > 0后
            if (clickFlag) {
     
            // btnLogin 登录按钮
                btnLogin.apply {
     
                    isEnabled = true
                    setBackgroundResource(R.color.white)
                    setTextColor(Color.BLACK)
                }
            // 不满足：
            } else {
     
                btnLogin.apply {
     
                    isEnabled = false
                    setBackgroundResource(R.color.white_cc)
                    setTextColor(Color.WHITE)
                }

            }
        }

Java:

（Java环境为1.8 支持lamda表达式）

public class EditTextMonitor implements TextWatcher {
     

    private PublishSubject<String> mPublishSubject;

    public EditTextMonitor(PublishSubject<String> publishSubject) {
     
        mPublishSubject = publishSubject;
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
     

    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
     

    }

    @Override
    public void afterTextChanged(Editable s) {
     
        mPublishSubject.onNext(s.toString());
    }
}

		// 处理登陆按钮是否可点击
        PublishSubject<String> mAccountSubject = PublishSubject.create();
        PublishSubject<String> mPasswordSubject = PublishSubject.create();
        edLoginAccount.addTextChangedListener(new EditTextMonitor(mAccountSubject));
        edLoginPwd.addTextChangedListener(new EditTextMonitor(mPasswordSubject));
        Observable.combineLatest(mAccountSubject, mPasswordSubject, (name, password) -> {
     
            int nameLen = name.length();
            int passwordLen = password.length();
            return nameLen > 0 && passwordLen > 0;
        }).subscribe(clickFlag -> {
     
            if (clickFlag) {
     
                btnLogin.setEnabled(true);
            } else {
     
                btnLogin.setEnabled(false);
            }
        });