EditText的学习

常用属性，界面跳转，按钮学习，按压颜色的变换，图片的插入学习等

工程目录：

                   

MainActivity.java:

package com.example.revrse;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
   private Button mBtnEditText;
   private Button mBtnTextView;
   private Button mBtnButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mBtnTextView=findViewById(R.id.btn_textview);
        mBtnTextView.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                //跳转到TextView演示界面
                Intent intent=new Intent(MainActivity.this,TextViewActivity.class);
                startActivity(intent);
            }
        });
        mBtnButton=findViewById(R.id.btn_button);
        mBtnButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                //跳转到Button演示界面
                Intent intent=new Intent(MainActivity.this,ButtonActivity.class);
                startActivity(intent);
            }
        });

    }
}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<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:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn_textview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#000000"
        android:text="TextView"/>

    <Button
        android:id="@+id/btn_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#000000"
        android:text="Button"/>

</LinearLayout>

TextViewActivity.java:

package com.example.revrse;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Paint;
import android.os.Bundle;
import android.widget.TextView;

public class TextViewActivity extends AppCompatActivity {
   private TextView mTv3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_text_view);
        mTv3=(TextView)findViewById(R.id.tv_3);
        mTv3.getPaint().setFlags(Paint.STRIKE_THRU_TEXT_FLAG);//中划线
        mTv3.getPaint().setAntiAlias(true);//去掉锯齿
    }
}

activity_text_view.xml:

<?xml version="1.0" encoding="utf-8"?>
<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:orientation="vertical"
    tools:context=".TextViewActivity">

    <TextView
        android:id="@+id/tv_1"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:maxLines="1"
        android:ellipsize="end"
        android:text="软件工程"
        android:textColor="#000000"
        android:textSize="24sp"
        android:layout_marginTop="10dp"/>

    <TextView
        android:id="@+id/tv_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="图片"
        android:drawableRight="@drawable/picture"
        android:textSize="24sp"
        android:layout_marginTop="10dp" />

    <TextView
        android:id="@+id/tv_3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="中划线"
        android:textColor="#000000"
        android:textSize="24sp"
        android:layout_marginTop="20dp"/>

        </LinearLayout>

ButtonActivity.java:

package com.example.revrse;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class ButtonActivity extends AppCompatActivity {
 private Button mBtn2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button);
        mBtn2=findViewById(R.id.btn_2);
        mBtn2.setOnClickListener(new View.OnClickListener(){
            @Override
            //弹出语句框方法一
            public void onClick(View v){
                Toast.makeText(ButtonActivity.this,"按钮2被点击了",Toast.LENGTH_SHORT).show();
            }
        });
    }
    public void showToast(View view){
        //弹出语句框
        //Toast.makeText(this,"点击",Toast.LENGTH_SHORT).show();//方法二
    }
}

activity_button.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=".ButtonActivity">

    <Button
        android:id="@+id/btn_1"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:text="按钮1"
        android:textSize="20sp"
        android:textColor="#ffffff"
        android:background="#ff0000"/>

    <Button
        android:id="@+id/btn_2"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:text="按钮2（按压变色）"
        android:textSize="20sp"
        android:textColor="#00ff33"
        android:background="#ffff00"
        android:layout_below="@+id/btn_1"
        android:onClick="showToast"
        android:layout_marginTop="10dp"
        tools:ignore="OnClick" />

</RelativeLayout>

.res.drawable

bg_button2.xml:(弹出语句框）

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

    <item android:state_pressed="true">
        <shape>
            <solid android:color="#ff9900"/>
            <corners android:radius="5dp"/>
        </shape>
    </item>
    <item android:state_pressed="false">
        <shape>
            <solid android:color="#ff9900"/>
            <corners android:radius="5dp"/>
        </shape>
    </item>

</selector>

运行截图：