如何實現GridView的單選功能

先看看效果 

如果是你需要的,你可以繼續往下看了

實現起來比較簡單,直接上代碼 
主Activity的佈局,一個Button用來跳轉到篩選Activity一個TextView用來顯示篩選後的到的結果

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.duanlian.gridviewsingleselectordomo.MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:onClick="buttonClick"
        android:text="去篩選"/>

    <TextView
        android:id="@+id/tv_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30dp"
        android:textColor="@color/colorAccent"
        android:layout_centerInParent="true"
        android:text="篩選結果"/>
</RelativeLayout>

• 
  

MainActivity你的代碼邏輯,註釋已經加上

package com.duanlian.gridviewsingleselectordomo;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private TextView mTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mTextView = (TextView) findViewById(R.id.tv_result);
    }

    /**
     * button的點擊監聽
     * @param view
     */
    public void buttonClick(View view) {
        //跳轉到篩選的activity
        Intent intent = new Intent(MainActivity.this, SingleSelectorActivity.class);
        //通過帶返回值的跳轉來的到下一個頁面帶過來的值
        startActivityForResult(intent,888);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 888 && resultCode == 999) {
            //拿到上一個頁面finish後帶過來的值
            String pos = data.getStringExtra("pos");
            mTextView.setText(pos);
        }


    }
}

• 
  

然後就是篩選Activity,佈局就一個GridView用來顯示待選項, 
一個Button用來點擊返回主Activity並且把選擇的值帶過去

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_single_selector"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.duanlian.gridviewsingleselectordomo.SingleSelectorActivity">
<Button
    android:id="@+id/button"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:onClick="buttonFinish"
    android:text="選擇完成"/>
    <GridView
        android:id="@+id/gridView"
        android:layout_below="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:columnWidth="80dp"
        android:horizontalSpacing="5dp"
        android:verticalSpacing="10dp"
        android:numColumns="auto_fit"/>
</RelativeLayout>

• 
  

然後就是篩選邏輯

package com.duanlian.gridviewsingleselectordomo;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;

import java.util.ArrayList;
import java.util.List;

public class SingleSelectorActivity extends AppCompatActivity {

    private GridView mGridView;
    private List<String> mList;
    private GridViewAdapter mAdapter;
    int selectorPosition = 0;

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

    private void initView() {
        mGridView = (GridView) findViewById(R.id.gridView);
        //添加數據
        mList = new ArrayList<>();
        for (int i = 0; i < 100; i++) {
            mList.add("第 " + i + " 個");
        }
        mAdapter = new GridViewAdapter(this, mList);
        mGridView.setAdapter(mAdapter);
        //gridView的點擊事件
        mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //把點擊的position傳遞到adapter裏面去
                mAdapter.changeState(position);
                selectorPosition = position;
            }
        });
    }

    /**
     * button的點擊監聽
     *
     * @param view
     */
    public void buttonFinish(View view) {
        Intent intent = new Intent();
        intent.putExtra("pos", "第 " + selectorPosition + " 個");
        setResult(999, intent);
        finish();
    }
}

• 
  

主要的狀態改變還是在Adapter裏面

package com.duanlian.gridviewsingleselectordomo;

import android.content.Context;
import android.graphics.Color;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.util.List;

/**
 * gridView的adapter
 */

public class GridViewAdapter extends BaseAdapter {
    private Context mContext;
    private List<String> mList;
    private int selectorPosition;

    public GridViewAdapter(Context context, List<String> mList) {
        this.mContext = context;
        this.mList = mList;

    }

    @Override
    public int getCount() {
        return mList != null ? mList.size() : 0;
    }

    @Override
    public Object getItem(int position) {
        return mList != null ? mList.get(position) : null;
    }

    @Override
    public long getItemId(int position) {
        return mList != null ? position : 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = View.inflate(mContext, R.layout.item_gridview, null);
        RelativeLayout mRelativeLayout = (RelativeLayout) convertView.findViewById(R.id.ll);
        TextView textView = (TextView) convertView.findViewById(R.id.tv);
        textView.setText(mList.get(position));
        //如果當前的position等於傳過來點擊的position,就去改變他的狀態
        if (selectorPosition == position) {
            mRelativeLayout.setBackgroundResource(R.drawable.grid_shap_two);
            textView.setTextColor(Color.parseColor("#FF4081"));
        } else {
            //其他的恢復原來的狀態
            mRelativeLayout.setBackgroundResource(R.drawable.grid_shap_one);
            textView.setTextColor(Color.parseColor("#3F51B5"));
        }
        return convertView;
    }


    public void changeState(int pos) {
        selectorPosition = pos;
        notifyDataSetChanged();

    }
}

• 
  

還有item佈局

<?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="wrap_content"
    >

    <RelativeLayout
        android:id="@+id/ll"
        android:layout_width="100dp"
        android:layout_height="32dp"
        android:layout_centerInParent="true"
        android:layout_margin="5dp"
        android:background="@drawable/grid_shap_one"
        >

        <TextView
            android:id="@+id/tv"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_centerHorizontal="true"
            android:ellipsize="none"
            android:gravity="center"
            android:singleLine="true"
            android:text="英超"
            android:maxLength="7"
            android:textColor="@color/colorPrimary"
            android:textSize="13sp"/>
    </RelativeLayout>
</RelativeLayout>

• 
  

如果你想點擊跳轉到篩選Activity且待篩選的按鈕中,顯示你之前選擇後的那個按鈕狀態是選中狀態,其實也很簡單,只要你把你選中後的position緩存下來,點進去到篩選Activity,實例化Adapter後調用 mAdapter.changeState(position);把你需要改變狀態的按鈕的position傳遞過去就行了

出自原創博主：https://blog.csdn.net/qq_15059163/article/details/80218486