1.布局一个ImageView和一个Button

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout    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"    
android:orientation="vertical"   
 tools:context="com.yaya.recordvideo.MainActivity">   
 <ImageView     
  android:id="@+id/iv_record_video"        
android:layout_width="200dp"        
android:layout_height="200dp"       
 android:src="@mipmap/ic_launcher"/>    
<Button        
android:layout_width="wrap_content"        
android:layout_height="wrap_content"     
android:id="@+id/btn_record"        
android:text="@string/record_video"/>
</LinearLayout>

2.添加相关权限：

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

3.MainActivity中代码的实现

package com.yaya.recordvideo;

import android.content.Context;
import android.content.CursorLoader;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.media.ThumbnailUtils;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;

public class MainActivity extends AppCompatActivity {
    private ImageView iv;
    private Button btn_record;
    private final int RESULT_CODE = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        iv = (ImageView) findViewById(R.id.iv_record_video);
        btn_record = (Button) findViewById(R.id.btn_record);
        btn_record.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
                //限制时长s
                intent.putExtra(MediaStore.EXTRA_DURATION_LIMIT, 30);
                //限制大小
                intent.putExtra(MediaStore.EXTRA_SIZE_LIMIT, 10*1024*1024);
                //设置质量
                intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
                //设置输出位置
//                intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.parse(Environment.getExternalStorageDirectory()+ File.separator+"gridview"+File.separator+System.currentTimeMillis()+".mp4"));
                startActivityForResult(intent, 1);
            }
        });
        iv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String path = (String) iv.getTag();
                if(path != null){
                    Intent videoFileIntent = getVideoFileIntent(new File(path));
                    startActivity(videoFileIntent);
                }else{
                    Toast.makeText(MainActivity.this, "不能打开这个视频", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    /**
     * 利用android系统播放添加好的视频
     * @param videoFile
     * @return
     */
    public Intent getVideoFileIntent(File videoFile)
    {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        intent.putExtra("oneshot", 0);
        intent.putExtra("configchange", 0);
        Uri uri = Uri.fromFile(videoFile);
        intent.setDataAndType(uri, "video/*");
        return intent;
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode==RESULT_OK){
            Uri uri = data.getData();
            //视频地址
            String videoPath = getPathFromUri(this,uri);
            //系统工具类ThumbnailUtils 获取视频的第一帧
            Bitmap videoThumbnail = ThumbnailUtils.createVideoThumbnail(videoPath, MediaStore.Video.Thumbnails.MICRO_KIND);
            if(videoThumbnail != null){
                iv.setImageBitmap(videoThumbnail);
                iv.setTag(videoPath);
            }else{
                Toast.makeText(this, "获取缩略图失败拉！", Toast.LENGTH_SHORT).show();
            }
        }
    }
    public static String getPathFromUri(Context mContext,Uri contentUri){

        String[] proj = { MediaStore.Images.Media.DATA};

        CursorLoader loader = new CursorLoader(mContext, contentUri, proj, null, null, null);

        Cursor cursor = loader.loadInBackground();

        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

        cursor.moveToFirst();
        String string = cursor.getString(column_index);
        cursor.close();
        return string;

    }
}