安卓开发之获取SD卡空间数据

package com.lidaochen.getsdcardspace;

import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;

import java.io.File;
import java.util.Formatter;

public class MainActivity extends AppCompatActivity {
    private TextView et_total;
    private TextView et_useAble;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 1.找到两个EditText控件
        et_total = (TextView)findViewById(R.id.et_total);
        et_useAble = (TextView)findViewById(R.id.et_useAble);
        // 2.获取SD卡总大小和可用空间
        File file = Environment.getExternalStorageDirectory();
        long totalSpace = file.getTotalSpace(); // 总大小
        long useAbleSpace = file.getUsableSpace(); // 可用空间大小
        // 3.展示到TextView上
        et_total.setText("总大小：" + String.format("%.2f", (double)totalSpace / (1024 * 1024 * 1024)) + "GB");
        et_useAble.setText("可用空间：" + String.format("%.2f", (double)useAbleSpace / (1024 * 1024 * 1024)) + "GB");
    }
}