大家都知道Rxjava神通廣大，無所不能，并有效避免Call Hell(回調(diào)地獄）模式，使大量的監(jiān)聽事件clickListener變換成流式編程，提高代碼閱讀性，提升代碼維護成本。今天我通過例子詳解Rxjava中的RxTextview詳解，讓你一舉搞懂Rxjava用法，語法以及操作實例（明白 簡單掌握）。

實際用戶場景舉例

根據(jù)用戶輸入的價格（價格范圍0.-1)、輸入的數(shù)量(10-無限）計算出總預(yù)計收入，如果寫錯了（舉例價格范圍錯誤、數(shù)量不對）賣出按鈕無效（disable).
如果用傳統(tǒng)的edittext.setOnChangeListner要加兩個，動態(tài)計算較為難以理解。用Rxjava 則合并兩個動態(tài)計算的Observable，最后動態(tài)算出結(jié)果，代碼如下。

  Observable<CharSequence> priceObservable = RxTextView.textChanges(priceEdit.getEditText());
        Observable<CharSequence> countObservable = RxTextView.textChanges(countEdit.getEditText());
        sellBtnSubscription = Observable.combineLatest(priceObservable, countObservable,
                (priceSequence, countSequence) -> {
                    if (priceSequence.toString().startsWith(".")) {
                        priceSequence = "0" + priceSequence;
                        priceEdit.setText("0.");
                        priceEdit.getEditText().setSelection(priceEdit.getText().length());
                    }
                    double inputPrice = StringUtils.isEmpty(priceSequence.toString()) ? 0 : Double.parseDouble(priceSequence.toString());
                    int inputCount = StringUtils.isEmpty(countSequence.toString()) ? 0 : Integer.parseInt(countSequence.toString());
                    return inputPrice > 0 && inputCount > 0;
                }).subscribe(new Observer<Boolean>() {
            @Override
            public void onCompleted() {

            }

            @Override
            public void onError(Throwable e) {
                e.printStackTrace();
            }

            @Override
            public void onNext(Boolean isSellBtnEnable) {
                sellBtn.setEnabled(isSellBtnEnable);
                String handFeetStr = "（含手續(xù)費）";
                if (isSellBtnEnable) {
                    double predictedIncome = Double.parseDouble(priceEdit.getText().toString()) * Integer.parseInt(countEdit.getText());
                    predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元");        //賣出聯(lián)豆的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    //（ 含手續(xù)費 ）
                    if (predictedIncome == 0) {
                        predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元");        //賣出聯(lián)豆的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    } else {
                        predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元" + handFeetStr);        //賣出聯(lián)豆的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    }
                } else {
                    predictedIncomeTv.setText(FormatUtil.formatMoney(0) + "元");        //賣出聯(lián)豆的預(yù)計收入
                }
            }
        });
    }

簡單詳解：

獲得兩個EditText的 可被觀察對象

獲得兩個edittext的可被觀察的（observable<CharSequence>對象

        Observable<CharSequence> priceObservable =
RxTextView.textChanges(priceEdit.getEditText());
        Observable<CharSequence> countObservable = 
RxTextView.textChanges(countEdit.getEditText());

綜合運算

動態(tài)算出 價格、數(shù)量是否合理

 sellBtnSubscription = Observable.combineLatest(priceObservable, countObservable,
                (priceSequence, countSequence) -> {
                    if (priceSequence.toString().startsWith(".")) {
                        priceSequence = "0" + priceSequence;
                        priceEdit.setText("0.");
                        priceEdit.getEditText().setSelection(priceEdit.getText().length());
                    }
                    double inputPrice = StringUtils.isEmpty(priceSequence.toString()) ? 0 : Double.parseDouble(priceSequence.toString());
                    int inputCount = StringUtils.isEmpty(countSequence.toString()) ? 0 : Integer.parseInt(countSequence.toString());
                    return inputPrice > 0 && inputCount > 0;
                }).subscribe(new Observer<Boolean>() {
            @Override
            public void onCompleted() {

            }

            @Override
            public void onError(Throwable e) {
                e.printStackTrace();
            }

            @Override
            public void onNext(Boolean isSellBtnEnable) {
                sellBtn.setEnabled(isSellBtnEnable);
                String handFeetStr = "（含手續(xù)費）";
                if (isSellBtnEnable) {
                    double predictedIncome = Double.parseDouble(priceEdit.getText().toString()) * Integer.parseInt(countEdit.getText());
                    predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元");        //賣出XX幣的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    //（ 含手續(xù)費 ）
                    if (predictedIncome == 0) {
                        predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元");        //賣出XX幣的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    } else {
                        predictedIncomeTv.setText(FormatUtil.formatMoney(predictedIncome) + "元" + handFeetStr);        //賣出XX幣的預(yù)計收入（沒有去除手續(xù)費的預(yù)估收入）
                    }
                } else {
                    predictedIncomeTv.setText(FormatUtil.formatMoney(0) + "元");        //賣出聯(lián)豆的預(yù)計收入
                }
            }
        });