Android自学之路4

Button组件
具有的一些功能
*文字大小颜色
*自定义背景形状
*自定义按压效果点击事件
*自定义点击事件

mainActivity

package com.example.myapplication;

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 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
            //跳转到Button界面
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,ButtonActivity.class);
                startActivity(intent);
            }
        });
    }
}

ButtonActivity

package com.example.myapplication;

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 mBtn3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button);
        mBtn3=findViewById(R.id.btn_3);
        mBtn3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(ButtonActivity.this,"btn3被点击了",Toast.LENGTH_LONG);
            }
        });
    }
    public void showToast(View view)
    {
        Toast.makeText(this,"我被点击了",Toast.LENGTH_SHORT).show();
    }
}

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">

    <Button
        android:id="@+id/btn_textview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="ViewTest"
       />
    <Button
        android:id="@+id/btn_button"
        android:text="ButtonTest"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
/>

</LinearLayout>

button.xml`

<?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"
    >
    <Button
        android:id="@+id/btn_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="按鈕1"
        android:textSize="20sp"
        android:textColor="#0066FF"
        android:background="#808080"

/>
    <Button
    android:id="@+id/btn_2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="按鈕2"
    android:textSize="20sp"
    android:textColor="#0066FF"
    android:background="@drawable/bg_btn2"
    android:layout_below="@+id/btn_1"
    android:layout_marginTop="10dp"
    />
    <Button
        android:id="@+id/btn_3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="按鈕3"
        android:textSize="20sp"
        android:textColor="#0066FF"
        android:background="@drawable/bg_btn3"
        android:layout_below="@+id/btn_2"
        android:layout_marginTop="10dp"
        />
    <Button
        android:id="@+id/btn_4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="按鈕4"
        android:layout_below="@id/btn_3"
        android:textSize="20sp"
        android:textColor="#0066FF"
        android:background="@drawable/bg_btn"
        android:layout_marginTop="10dp"
        android:onClick="showToast"


        />
</RelativeLayout>

drawable下
btn.xml

<?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="#11EEEE"/>
            <corners android:radius="5dp"/>
        </shape>>
    </item>>
    <item android:state_pressed="false">
        <shape>
            <solid android:color="#FF9900"/>
            <corners android:radius="5dp"/>
    </shape>>
    </item>>
    </selector>

btn2.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid
android:color="#CC33CC" />
    <corners
        android:radius="5dp"
        />


</shape>

btn.xml3`

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
<stroke
    android:width="1dp"
    android:color="#FF9900"
    />
    <corners
        android:radius="5dp"
        />


</shape>

效果如图