Bitmap保存图片到指定路径

1.manifests文件需要增加权限。

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

2.在Android Q设备上有两种方式来让分区存储生效：以 Android 9 或更低版本为目标平台 （Target SDK <=28）如果Target SDK > 28，请在manifest中添加android:requestLegacyExternalStorage=“true”。

    <application
        android:allowBackup="true"
      ...
        android:requestLegacyExternalStorage="true"
        android:theme="@style/AppTheme">

3.获取外部存储路径,定义图片的存储路径,判断图片的存储路径是否存在，不存在则建立。

private static final String SD_PATH = Environment.getExternalStorageDirectory().getPath() + "/fileimage/";
private static final String IN_PATH = Environment.getExternalStorageDirectory().getPath() + "/fileimage/";   
 public static String saveToBitmapfile(Bitmap bmp, String desFileName, Context context) {
        String savePath;
        File file;
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            savePath = SD_PATH;
        } else {
            savePath = IN_PATH;
        }
        try {
            file = new File(savePath + generateFileName() + ".JPEG");
            if (!file.exists()) {
                file.getParentFile().mkdirs();
            }
            FileOutputStream fos = new FileOutputStream(file);
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, fos);
            fos.flush();
            fos.close();
            Toast.makeText(context, "保存成功,位置:" + file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }

        return file.getAbsolutePath();
    }
    private static String generateFileName() {
        return UUID.randomUUID().toString();
    }

4.activity实现code,通过截屏方式，并指定路径进行保存。

public class TestActivity extends Activity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
       //请求写入权限
       ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                1001);
        Button screenBt = (Button) findViewById(R.id.screen_button);
        screenBt.setOnClickListener(new View.OnClickListener() {
            private Bitmap mBitmap;
            @Override
            public void onClick(View v) {
            //截屏生成bitmap
                mBitmap=ScreenWindow();
                //指定路径，并进行保存
                saveToBitmapfile(mBitmap,System.currentTimeMillis() + "",getApplicationContext());
            }
        });
    }
    public Bitmap ScreenWindow() {
        getWindow().getDecorView().setDrawingCacheEnabled(true);
        Bitmap bmp = getWindow().getDecorView().getDrawingCache();
        return bmp;
    }
    //重写权限回调
        @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (grantResults.length == 0 || PackageManager.PERMISSION_GRANTED != grantResults[0]) {
            Toast.makeText(this, "你拒绝了权限，无法创建!", Toast.LENGTH_LONG).show();
        }
    }