Android Studio简易项目|随机选择器（类似转盘）

一、背景

为了强化对flowlayout流式布局的理解和简易安卓项目架构结构的理解，写一个小项目，随机选择器，控制可见等

二、项目代码

2.1流式布局

XML 复制代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="8dp"
    android:background="@drawable/item_background">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textSize="16sp"
         />
</LinearLayout>

2.2布局文件

XML 复制代码

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/tip"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        >

        <EditText
            android:id="@+id/tip_title"
            android:layout_width="200dp"
            android:layout_height="50dp"
            android:hint="@string/btn_edit"
            android:gravity="center"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"

            >

        </EditText>

        <android.widget.Button
            android:id="@+id/btn_save"
            android:layout_width="80dp"
            android:layout_height="40dp"
            android:layout_marginStart="@dimen/margin_200"
            android:layout_marginBottom="8dp"
            android:background="@drawable/btn_background"
            android:text="@string/btn_save"
            android:textColor="@color/white"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintStart_toEndOf="@+id/tip_title"></android.widget.Button>

    </androidx.constraintlayout.widget.ConstraintLayout>



    <com.google.android.material.internal.FlowLayout
        android:id="@+id/flowLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="16dp"
        android:orientation="horizontal"
        app:lineSpacing="@dimen/margin_80"
        android:layout_marginTop="@dimen/margin_100"
        app:layout_constraintTop_toBottomOf="@+id/tip"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        >
    </com.google.android.material.internal.FlowLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/selector"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/margin_100"
        app:layout_constraintTop_toBottomOf="@id/flowLayout"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        >
        <android.widget.Button
            android:id="@+id/btn_random"
            android:layout_width="100dp"
            android:layout_height="80dp"
            android:textColor="@color/white"
            android:background="@drawable/btn_background"
            android:text="@string/btn_choose"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            >
        </android.widget.Button>
        <android.widget.Button
            android:id="@+id/btn_clear"
            android:layout_width="100dp"
            android:layout_height="80dp"
            android:textColor="@color/white"
            android:background="@drawable/btn_background"
            android:text="@string/btn_clear"
            android:layout_marginStart="60dp"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintStart_toEndOf="@+id/btn_random"
            >
        </android.widget.Button>
    </androidx.constraintlayout.widget.ConstraintLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/margin_400"
        app:layout_constraintTop_toBottomOf="@+id/selector"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:id="@+id/sel_show">

        <TextView
            android:id="@+id/sel_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/sel_ans"
            android:visibility="gone"
            android:textColor="@color/black"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            >
        </TextView>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/sel_ans"
            android:visibility="gone"
            android:layout_marginStart="@dimen/margin_400"
            android:background="@drawable/btn_background"
            app:layout_constraintStart_toEndOf="@+id/sel_text"
            app:layout_constraintTop_toTopOf="parent"
            >
        </TextView>


    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.constraintlayout.widget.ConstraintLayout>

2.3 主要代码

java 复制代码

package com.example.javatestwithleetcode.ui;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.example.javatestwithleetcode.R;
import com.example.javatestwithleetcode.utils.StringUtils;
import com.example.javatestwithleetcode.utils.ToastUtils;
import com.google.android.material.internal.FlowLayout;
import java.util.ArrayList;
import java.util.Random;

public class MainActivity extends AppCompatActivity {

    private FlowLayout flowLayout;
    private ArrayList<String> dataList;
    private Button button;
    private Button save_btn;
    private EditText editText;
    private Button clear_btn;
    private TextView sel_ans;
    private TextView sel_title;



    @SuppressLint("ResourceAsColor")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initDatas();
        //也可以用implements然后switch-case 也可以拆开放三个方法里
        button.setOnClickListener(view -> {
            Random random=new Random();
            int i= random.nextInt(dataList.size());
//            ToastUtils.showToast(dataList.get(i));
            sel_ans.setText(dataList.get(i));
            sel_ans.setVisibility(View.VISIBLE);
            sel_title.setVisibility(View.VISIBLE);
        });
        save_btn.setOnClickListener(v->{
            editText=(EditText) findViewById(R.id.tip_title);
            if(StringUtils.isNotEmpty(editText.getText().toString()) ){
                dataList.add(editText.getText().toString());
                editText.setText("");
                // 将数据添加到FlowLayout
                addDataToFlowLayout(dataList);
            }else{
                ToastUtils.showToast("请输入后再保存");
            }
        });
        clear_btn.setOnClickListener(v->{
            dataList.clear();
            flowLayout.removeAllViews();
            sel_ans.setVisibility(View.GONE);
            sel_title.setVisibility(View.GONE);
        });

    }

    private void addDataToFlowLayout(ArrayList<String> dataList) {
        if(dataList.isEmpty()){
            return;
        }
        flowLayout.removeAllViews();
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        layoutParams.setMargins(0, 0, getResources().getDimensionPixelSize(R.dimen.margin_100), 0);
        LayoutInflater inflater = LayoutInflater.from(this);
        for (String data : dataList) {
            View view = inflater.inflate(R.layout.item_flowlayout, flowLayout, false);
            TextView textView = view.findViewById(R.id.textView);
            textView.setText(data);
            textView.setPadding(getResources().getDimensionPixelSize(R.dimen.margin_40), getResources().getDimensionPixelSize(R.dimen.margin_40)
                    , getResources().getDimensionPixelSize(R.dimen.margin_40), getResources().getDimensionPixelSize(R.dimen.margin_40));
            textView.setSingleLine();
            textView.setTextColor(getResources().getColor(R.color.white));
            textView.setLayoutParams(layoutParams);
            flowLayout.addView(view,layoutParams);
        }
    }

    private void initDatas(){
        setContentView(R.layout.activity_main);
        dataList = new ArrayList<>();
        flowLayout = findViewById(R.id.flowLayout);
        sel_ans=(TextView) findViewById(R.id.sel_ans);
        sel_title=(TextView) findViewById(R.id.sel_text);
        sel_ans.setPadding(getResources().getDimensionPixelSize(R.dimen.margin_80),getResources().getDimensionPixelSize(R.dimen.margin_80)
                ,getResources().getDimensionPixelSize(R.dimen.margin_80),getResources().getDimensionPixelSize(R.dimen.margin_80));
        button =(Button) findViewById(R.id.btn_random);
        save_btn=(Button) findViewById(R.id.btn_save);
        clear_btn=(Button) findViewById(R.id.btn_clear);
    }
}

资源文件和mainfest还有工具类不作详细解释。

三、项目截图

图片放不出来。。。

四、重点

添加flowlayout，以及设置可见性，加强了对android studio项目中的textview edittext button的更深的认知，点击触发条件等，以及对constraintlayout，linerlayout和flowlayout也有了更深刻的认知