6.常用UI组件

文字类组件

文本框组件

<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="这是一个文本框"
        android:textSize="32dp"
        android:textColor="@color/colorAccent"
        android:maxWidth="180dp"
        />

编辑框

<EditText
        android:id="@+id/e1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="hint设置提示信息"
        android:lines="3"
        android:drawableLeft="@mipmap/hurt"
        />

   android:lines---------设置文本框所占行数。

EditText e1 = findViewById(R.id.e1);
        e1.getText();

按钮

普通按钮

 <Button
        android:id="@+id/b1"
        android:text="button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

一：匿名内部类作为单击事件监听器。

package com.example;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = findViewById(R.id.b1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(MainActivity.this,"点击了按钮",Toast.LENGTH_SHORT).show();
            }
        });
    }
}

二：通过onClick属性实现
在Activity中添加一个包含View类型参数的方法：

 public void myClick(View view){
        Toast.makeText(MainActivity.this,"点击了按钮2",Toast.LENGTH_SHORT).show();
    }

将xml文件中android:onClick属性指定为步骤一中的方法名：

android:onClick="myClick"

图片按钮

<ImageButton
        android:background="#0000"
        android:src="@mipmap/hurt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

单选按钮

<?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=".MainActivity">
    <RadioGroup
        android:id="@+id/r1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="男" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="保密" />
    </RadioGroup>

</RelativeLayout>

package com.example;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RadioGroup radioGroup = findViewById(R.id.r1);
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                RadioButton r = findViewById(i);
                Toast.makeText(MainActivity.this,r.getText(),Toast.LENGTH_SHORT).show();
            }
        });
    }

}

运行截图：

通过另一个按钮来显示选中的值（使用自定义的方法）

<?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">
    <RadioGroup
        android:id="@+id/r1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="男" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="保密" />

    </RadioGroup>

    <Button
        android:id="@+id/b1"
        android:onClick="onClick"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="控制"/>

</LinearLayout>

package com.example;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    Button b1;
    RadioGroup radioGroup;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        radioGroup = findViewById(R.id.r1);
        b1 = findViewById(R.id.b1);
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                RadioButton r = findViewById(i);
                Toast.makeText(MainActivity.this,r.getText(),Toast.LENGTH_SHORT).show();
            }
        });
    }
    public void onClick(View view){
        for(int i=0;i<radioGroup.getChildCount();i++){
            RadioButton rr = (RadioButton) radioGroup.getChildAt(i);
            if (rr.isChecked()){
                Toast.makeText(MainActivity.this,rr.getText(),Toast.LENGTH_SHORT).show();
                break;
            }
        }
    }

}

复选框

<?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">

    <CheckBox
        android:id="@+id/c1"
        android:text="checkbox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <CheckBox
        android:id="@+id/c2"
        android:text="checkbox2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <CheckBox
        android:id="@+id/c3"
        android:text="checkbox3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <CheckBox
        android:id="@+id/c4"
        android:text="checkbox4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

package com.example;

import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
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.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    CheckBox like1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        like1 = findViewById(R.id.c1);
        like1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if(like1.isChecked()){
                    Toast.makeText(MainActivity.this,like1.getText(),Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

}

日期选择器

<?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">

    <DatePicker
        android:id="@+id/c1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    int year,month,day;
    DatePicker datePicker;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        datePicker = (DatePicker) findViewById(R.id.c1);
        Calendar calendar = Calendar.getInstance();
        year = calendar.get(Calendar.YEAR);
        month = calendar.get(Calendar.MONTH);
        day = calendar.get(Calendar.DAY_OF_MONTH);
        datePicker.init(year, month, day, new DatePicker.OnDateChangedListener() {
            @Override
            public void onDateChanged(DatePicker datePicker, int i, int i1, int i2) {
                MainActivity.this.year = i;
                MainActivity.this.month = i1;
                MainActivity.this.day = i2;
                show(year,month,day);
            }
        });
    }
    private void show(int year,int month,int day){
        String str = year + "年" + (month+1) + "月" + day + "日";
        Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT);
    }
}

时间选择器

<TimePicker
        android:id="@+id/t1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </TimePicker>

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.TimePicker;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    TimePicker tp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tp = findViewById(R.id.t1);
        tp.setIs24HourView(true);//改成24小时制
        tp.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
            @Override
            public void onTimeChanged(TimePicker timePicker, int i, int i1) {
                String str = i + "时" + i1 + "分";
                Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT).show();
            }
        });
    }

}

计时器

<Chronometer
        android:id="@+id/c1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FFFF00"
        android:layout_centerHorizontal="true"
       />

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.SystemClock;
import android.widget.Chronometer;
import android.widget.DatePicker;
import android.widget.TimePicker;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    Chronometer ch;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ch = findViewById(R.id.c1);
        //设置起始时间
        ch.setBase(SystemClock.elapsedRealtime());
        //设置时间格式
        ch.setFormat("%s");
        ch.start();
        ch.setOnChronometerTickListener(new Chronometer.OnChronometerTickListener() {
            @Override
            public void onChronometerTick(Chronometer chronometer) {
                if(SystemClock.elapsedRealtime()-ch.getBase()>=60000){
                    ch.stop();
                }
            }
        });
    }

}