UI组件之EditText

EditText:一个可以输入的控件

• 常用属性

• 监听事件

• 简单登录界面制作

练习代码

activity_main.xml

<Button
        android:id="@+id/btn_edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="EditText"
        android:textAllCaps="false"/>

MainActivity.java

public class MainActivity extends AppCompatActivity {
     private Button mBtnEditText;
     @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 mBtnEditText = findViewById(R.id.btn_edittext);
        mBtnEditText.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //跳转到EditText页面
                Intent intent = new Intent(MainActivity.this, EditTextActivity.class);
                startActivity(intent);
            }
        });
    }

activity_edit_text.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".EditTextActivity">

    <EditText
        android:id="@+id/et_1"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textSize="16sp"
        android:textColor="#008B00"
        android:hint="用户名"
        android:background="@drawable/bg_username"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:layout_margin="10dp"
        android:drawableLeft="@drawable/icon_user"
        android:drawablePadding="5dp"
        android:maxLines="1"/>

    <EditText
        android:id="@+id/et_2"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textSize="16sp"
        android:textColor="#008B00"
        android:inputType="textPassword"
        android:hint="密码"
        android:layout_below="@+id/et_1"
        android:layout_marginTop="15dp"
        android:background="@drawable/bg_username"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:layout_margin="10dp"
        android:drawableLeft="@drawable/icon_password"
        android:drawablePadding="5dp"
        android:maxLines="1"/>

    <EditText
        android:id="@+id/et_3"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textSize="16sp"
        android:textColor="#008B00"
        android:hint="手机号"
        android:layout_below="@+id/et_2"
        android:inputType="number"
        android:layout_marginTop="15dp"
        android:background="@drawable/bg_username"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:layout_margin="10dp"/>

    <Button
        android:id="@+id/btn_login"
        android:layout_width="136dp"
        android:layout_height="wrap_content"
        android:layout_below="@+id/et_3"
        android:layout_centerInParent="true"
        android:layout_marginTop="40dp"
        android:background="@drawable/bg_btn4"
        android:text="登录"
        android:textColor="#000000"
        android:textSize="20sp" />

</RelativeLayout>

EditTextActivity.java

package com.example.helloworld;

import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class EditTextActivity extends AppCompatActivity {

    private Button mBtnLogin;
    private EditText mEtUserName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_text);
        mBtnLogin = findViewById(R.id.btn_login);
        mBtnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(EditTextActivity.this, "登陆成功", Toast.LENGTH_SHORT).show();
            }
        });

        mEtUserName = findViewById(R.id.et_1);
        mEtUserName.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

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

                Log.d("edittext",s.toString());
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });

    }
}