2022-10-12学习内容

1.长按点击事件

1.1activity_button_long_click.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn_long_click"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="指定长按的点击监听器"
        android:textColor="#000000"
        android:textSize="15sp" />

    <TextView
        android:id="@+id/tv_result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:gravity="center"
        android:textColor="#000000"
        android:textSize="15sp"
        android:text="这里查看按钮的点击结果"/>

</LinearLayout>

1.2ButtonLongClickActivity.java

package com.example.chapter03;

import androidx.appcompat.app.AppCompatActivity;

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

import com.example.chapter03.utils.DateUtil;

public class ButtonLongClickActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button_long_click);
        TextView tv_result = findViewById(R.id.tv_result);
        Button btn_long_click = findViewById(R.id.btn_long_click);
        btn_long_click.setOnLongClickListener(v -> {
            String desc = String.format("%s 您点击了按钮； %s", DateUtil.getNowTime(), ((Button)v).getText());
            tv_result.setText(desc);
               return true;
        });
    }
}

1.3效果

2.禁用与恢复按钮

2.1activity_button_enable.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_enable"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="启用测试按钮"
            android:textColor="#000000"
            android:textSize="17sp"/>

        <Button
            android:id="@+id/btn_disable"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="禁用测试按钮"
            android:textColor="#000000"
            android:textSize="17sp"/>

    </LinearLayout>

        <Button
            android:id="@+id/btn_test"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="测试按钮"
            android:textColor="#888888"
            android:textSize="17sp"
            android:enabled="false"/>

        <TextView
            android:id="@+id/tv_result"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="这里查看测试按钮的点击结果"
            android:textColor="#000000"
            android:textSize="17sp" />

</LinearLayout>

2.2ButtonEnableActivity.java

package com.example.chapter03;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.example.chapter03.utils.DateUtil;

public class ButtonEnableActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_test;
    private TextView tv_result;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button_enable);
        Button btn_enable = findViewById(R.id.btn_enable);
        Button btn_disable = findViewById(R.id.btn_disable);
        btn_test = findViewById(R.id.btn_test);
        tv_result = findViewById(R.id.tv_result);

        btn_enable.setOnClickListener(this);
        btn_disable.setOnClickListener(this);
        btn_test.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_enable:
                // 启用当前控件
                btn_test.setEnabled(true);
                // 设置按钮的文字颜色
                btn_test.setTextColor(Color.BLACK);
                break;
            case R.id.btn_disable:
                // 禁用当前控件
                btn_test.setEnabled(false);
                btn_test.setTextColor(Color.GRAY);
                break;
            case R.id.btn_test:
                String desc = String.format("%s 您点击了按钮； %s", DateUtil.getNowTime(), ((Button)v).getText());
                tv_result.setText(desc);
                break;
        }
    }
}

2.3效果