如何在不单击按钮的情况下将按时用户输入文本从EditView设置为TextView

问题描述

我正在练习，我被困在某一时刻，我想将按时用户输入文本从EditText设置为TextView，但是我不知道该怎么做，所以我在这里搜索并找到了{{3 }} 我遵循了这个步骤，但是它没有用，所以我决定发布一个新问题，以了解是否有任何改进。

这是我的简单XML

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fff"
android:orientation="vertical"
android:padding="10dp"
tools:context=".MainActivity">

<TextView
    android:id="@+id/tv1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="40dp"
    android:text="Hello World!"
    android:textColor="#000"
    android:textSize="20sp" />

<TextView
    android:id="@+id/tv2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="20dp"
    android:text="Hello World!"
    android:textColor="#000"
    android:textSize="20sp" />

<EditText
    android:id="@+id/et1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:inputType="text" />

<EditText
    android:id="@+id/et2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:inputType="text" />

</LinearLayout>

这是我的Java代码

package com.example.ontimedata;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

TextView tv1,tv2;
EditText et1,et2;
String data1,data2;

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

    tv1 = findViewById(R.id.tv1);
    tv2 = findViewById(R.id.tv2);
    et1 = findViewById(R.id.et1);
    et2 = findViewById(R.id.et2);

    TextWatcher textWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s,int start,int count,int after) {
            Log.d("TAG","beforeTextChanged: ");
            data1 = et1.getText().toString();
        }

        @Override
        public void onTextChanged(CharSequence s,int before,int count) {
            Log.d("TAG","onTextChanged: ");
            data1 = et1.getText().toString();
        }

        @Override
        public void afterTextChanged(Editable s) {
            Log.d("TAG","afterTextChanged: ");
            data1 = et1.getText().toString();
        }
    };
    tv1.addTextChangedListener(textWatcher);
    Log.d("TAG","onCreate: ");


    TextWatcher textWatcher1 = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s,int after) {

        }

        @Override
        public void onTextChanged(CharSequence s,int count) {
            data2 = et2.getText().toString();
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    };
    tv2.addTextChangedListener(textWatcher1);
}
}

如果您回答这个问题，请先感谢。

解决方法

在代码中，将侦听器设置为TextView（tv1），必须将其添加到EditText（et1）。您可以这样做：

import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.widget.EditText;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity
{
    TextView tv1;
    EditText et1;

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

        tv1 = findViewById(R.id.tv1);
        et1 = findViewById(R.id.et1);

        TextWatcher textWatcher = new TextWatcher()
        {
            @Override
            public void beforeTextChanged(
                    CharSequence s,int start,int count,int after
            )
            {
                Log.d("MyTag","beforeTextChanged: "
                );
            }

            @Override
            public void onTextChanged(
                    CharSequence s,int before,int count
            )
            {
                Log.d("MyTag","onTextChanged: "
                );
            }

            @Override
            public void afterTextChanged(Editable s)
            {
                Log.d("MyTag","afterTextChanged: "
                );

                tv1.setText(s); // set TextView text to Text inside EditText
            }
        };

        et1.addTextChangedListener(textWatcher); // add Listener to EditText
    }
}

,

简要说明。 “按时用户输入”是什么？ 但是，如果您想在输入editText时更改textView。 只需在onTextChanged（）中执行此操作即可：

public void onTextChanged(CharSequence s,int count) {
        textView.setText(editText.getText().toString().trim());
    }

,

从文本查看器获取文本后，只需更改TextView，就需要这样的东西：

TextWatcher textWatcher = new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence s,int after) {
        Log.d("TAG","beforeTextChanged: ");
        //data1 = et1.getText().toString();
    }

    @Override
    public void onTextChanged(CharSequence s,int count) {
        Log.d("TAG","onTextChanged: ");
        //data1 = et1.getText().toString();
    }

    @Override
    public void afterTextChanged(Editable s) {
        Log.d("TAG","afterTextChanged: ");
        String text = s.toString();
        tv1.setText(text)
    }
};