今日所学—Android中简单控件的使用

 

 

 

 

 

 下面是相关的代码：

activity_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">


    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="212dp"
        android:layout_marginLeft="212dp"
        android:layout_marginTop="76dp"
        android:text="TextView"
        android:textColor="#ff0000"
        android:textSize="30sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="52dp"
        android:layout_marginLeft="52dp"
        android:layout_marginTop="296dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="用户名"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="236dp"
        android:layout_marginLeft="236dp"
        android:layout_marginBottom="144dp"
        android:text="点击"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <CheckBox
        android:id="@+id/checkBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="76dp"
        android:layout_marginLeft="76dp"
        android:layout_marginTop="34dp"
        android:checked="true"
        android:text="CheckBox"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText" />

    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="79dp"
        android:layout_marginLeft="79dp"
        android:layout_marginTop="20dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/checkBox">

        <RadioButton
            android:id="@+id/radioButton"
            android:layout_width="match_parent"
            android:layout_height="46dp"
            android:text="RadioButton" />

        <RadioButton
            android:id="@+id/radioButton2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="RadioButton" />

    </RadioGroup>

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="40dp"
        android:layout_marginLeft="40dp"
        android:layout_marginTop="128dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@tools:sample/avatars[0]" />


</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.example.kongjian;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;

import static android.icu.text.DisplayContext.LENGTH_SHORT;

public class MainActivity extends AppCompatActivity {
    private ImageView imageView;
    private TextView textView;
    private EditText editText;
    private RadioGroup radioGroup;
    private CheckBox checkBox;
    private Button button;


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

        button=findViewById(R.id.button);
        imageView=findViewById(R.id.imageView);
        textView=findViewById(R.id.textView);
        editText=findViewById(R.id.editText);
        radioGroup=findViewById(R.id.radioGroup);
        checkBox=findViewById(R.id.checkBox);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String edit=editText.getText().toString();
                textView.setText(edit);
                imageView.setImageResource(R.drawable.ic_launcher_background);

            }
        });
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                if(checkedId==R.id.radioButton){
                    Toast.makeText(getApplicationContext(),"1已选择",Toast.LENGTH_SHORT).show();
                }else{
                    Toast.makeText(getApplicationContext(),"2已选择",Toast.LENGTH_SHORT).show();
                }
            }
        });
        checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if(isChecked){
                    Toast.makeText(getApplicationContext(),"已选择",Toast.LENGTH_SHORT).show();
                }else{
                    Toast.makeText(getApplicationContext(),"没有选择",Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

效果截图：