临时文本，草稿

package com.example.fanfeng.edittextdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity implements TextWatcher {

    private android.widget.EditText et1;
    private android.widget.EditText et2;

    int maxTextNum = 0;
    String tempText = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.et1 = (EditText) findViewById(R.id.et1);
        this.et2 = (EditText) findViewById(R.id.et2);

        int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        et1.measure(w, h);
        int width = et1.getMeasuredWidth();

        et1.addTextChangedListener(this);

        //退格键监听，如果内部没有文本就把焦点给et1
        et2.setOnKeyListener(new View.OnKeyListener(){

            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if(keyCode == KeyEvent.KEYCODE_DEL){
                    //如果et2内容为空，则焦点给et1
                    if(TextUtils.isEmpty(et2.getText())){
                        et2.clearFocus();
                        et1.requestFocus();//代码动态设置焦点（实现）
                    }
                }
                return false;
            }
        });

        //获取焦点监听，如果里面没有文本，就把焦点给et1
        et2.setOnFocusChangeListener(new android.view.View.
                OnFocusChangeListener() {
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                if (hasFocus) {
                    // 此处为得到焦点时的处理内容
                    if(TextUtils.isEmpty(et2.getText())){
                        et2.clearFocus();
                        et1.requestFocus();//代码动态设置焦点（实现）
                    }

                } else {
                    // 此处为失去焦点时的处理内容
                }
            }
        });
    }

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

    }

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

        tempText = et2.getText().toString();

        int measureText=(int)et1.getPaint().measureText(s.toString());
        Log.e("xxx","文本：" + s.toString() + "--输入长度：" + measureText + "控件宽度：" + et1.getWidth());

        //如果输入的文字长度大于控件的宽度，就截取最后一个字符到下一行
        if(measureText > et1.getWidth()){
            et1.setText(s.toString().substring(0, s.length()-1));
            et1.setSelection(et1.getText().length());
            if(s.length()-1 >= 0 ){
                tempText = s.toString().substring(s.length()-1, s.length()) + tempText;
            }
            et2.setText(tempText);

            Log.e("xxx","tempText：" + tempText);

            //如果文本长度与控件宽度相差大于一个字符的宽度，并且et2有内容
        }else if((measureText < et1.getWidth() - (int)(et1.getPaint().getTextSize() * 1.2)) && !TextUtils.isEmpty(tempText)){

            String tempStr = tempText.substring(0, 1);
            et1.setText(et1.getText() + tempStr);
            et1.setSelection(et1.getText().length());
            tempText = tempText.substring(1, tempText.length());
            et2.setText(tempText);
        }
    }

    @Override
    public void afterTextChanged(Editable s) {

    }
}