1月13日 EditText

EditText

通过学习editText的使用做了一个简单的登录界面

package com.example.firstapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.Intent;
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 java.util.Map;

public class EditTextActivity extends AppCompatActivity {
    private Button mBtnLogin;
    private EditText mEtUserName;//声明空间
    private EditText editname;
    private EditText editpasswd;
    private String strname;
    private String strpasswd;
    private SharedHelper sh;
    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_text);
        mContext = getApplicationContext();
        sh = new SharedHelper(mContext);

        mBtnLogin = findViewById(R.id.btn_login);
        editname=findViewById(R.id.et_1);
        editpasswd=findViewById(R.id.et_2);
        mBtnLogin.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v){
                strname=editname.getText().toString();
                strpasswd=editpasswd.getText().toString();
                sh.save(strname,strpasswd);
                Toast.makeText(EditTextActivity.this,"登录成功!",Toast.LENGTH_SHORT).show();
                Intent intent = new Intent(EditTextActivity.this,MainActivity.class);
                startActivity(intent);
            }
        });
        mEtUserName = findViewById(R.id.et_1);//监听事件
        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) {

            }
        });
    }
    @Override
    protected void onStart() {
        super.onStart();
        Map<String,String> data = sh.read();
        editname.setText(data.get("username"));
        editpasswd.setText(data.get("passwd"));
    }
}

layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="15dp">

    <EditText
        android:id="@+id/et_1"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_marginTop="25dp"
        android:background="@drawable/bg_username"
        android:drawableLeft="@drawable/yonghum"
        android:drawablePadding="7dp"
        android:hint="用户名："
        android:maxLines="1"
        android:paddingLeft="10dp"
        android:textSize="16sp" />

    <EditText
        android:id="@+id/et_2"
        android:layout_width="match_parent"
        android:textSize="16sp"
        android:hint="密码："
        android:inputType="textPassword"
        android:layout_below="@id/et_1"
        android:layout_height="50dp"
        android:drawableLeft="@drawable/mimasuo"
        android:maxLines="1"
        android:layout_marginTop="25dp"
        android:drawablePadding="7dp"
        android:background="@drawable/bg_username"
        android:paddingLeft="10dp"/>
    <Button
        android:id="@+id/btn_login"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_below="@id/et_2"
        android:layout_marginTop="25dp"
        android:text="登录"
        android:textSize="25sp"
        android:textColor="#fff"
        android:background="@drawable/bg_btn4"/>
</RelativeLayout>