我通过点击按钮在Android中创建截图，但无法保存图像。我在“没有这样的文件或目录”中有一条错误消息。我该怎么办？
我的代码：
public class MainActivity extends Activity {
LinearLayout L1;
ImageView image;
Bitmap bm;
File file;
FileOutputStream fileoutputstream;
View v1;
ByteArrayOutputStream bytearrayoutputstream;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bytearrayoutputstream = new ByteArrayOutputStream();
L1 = (LinearLayout) findViewById(R.id.layout);
Button but = (Button) findViewById(R.id.Button01);
but.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
View v1 = L1.getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bm = v1.getDrawingCache();
BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
image = (ImageView) findViewById(R.id.ImageView02);
image.setBackgroundDrawable(bitmapDrawable);
Log.e("top-->", String.valueOf(bitmapDrawable));
bm.compress(Bitmap.CompressFormat.PNG,60,bytearrayoutputstream);
//String path = Environment.getExternalStorageDirectory().toString();
File myDir = new File(Environment.getExternalStorageDirectory(), "saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try
{
FileOutputStream out = new FileOutputStream(file);
bm.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
});
final ScrollView scrollview = (ScrollView) findViewById(R.id.scroll);
scrollview.getViewTreeObserver().addOnScrollChangedListener(new ViewTreeObserver.OnScrollChangedListener(){
@Override
public void onScrollChanged() {
if (scrollview != null) {
if (scrollview.getChildAt(0).getBottom() <= (scrollview.getHeight() + scrollview.getScrollY())) {
View v1 = L1.getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bm = v1.getDrawingCache();
BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
image = (ImageView) findViewById(R.id.ImageView02);
image.setBackgroundDrawable(bitmapDrawable);
Log.e("top-->", String.valueOf(bitmapDrawable));
bm.compress(Bitmap.CompressFormat.PNG,60,bytearrayoutputstream);
//String path = Environment.getExternalStorageDirectory().toString();
File myDir = new File(Environment.getExternalStorageDirectory(), "saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try
{
FileOutputStream out = new FileOutputStream(file);
bm.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
}
catch (Exception e)
{
e.printStackTrace();
}
} else {
View v1 = L1.getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bm = v1.getDrawingCache();
BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
image = (ImageView) findViewById(R.id.ImageView01);
image.setBackgroundDrawable(bitmapDrawable);
Log.e("bottom-->", String.valueOf(bitmapDrawable));
bm.compress(Bitmap.CompressFormat.PNG,60,bytearrayoutputstream);
// String path = Environment.getExternalStorageDirectory().toString();
File myDir = new File(Environment.getExternalStorageDirectory(), "saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try
{
FileOutputStream out = new FileOutputStream(file);
bm.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
});
}
}
图片无法保存在SD卡中。我犯了什么错误？我无法理解问题是什么或如何在SD卡上保存图像？
答案 0 :(得分：0)
我使用此方法捕获屏幕。首先，添加适当的权限以保存文件：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
这是代码（在Activity中运行）：
private void takeScreenshot() {
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);
try {
// image naming and path to include sd card appending name you choose for file
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
// create bitmap screen capture
View v1 = getWindow().getDecorView().getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
File imageFile = new File(mPath);
FileOutputStream outputStream = new FileOutputStream(imageFile);
int quality = 100;
bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
outputStream.flush();
outputStream.close();
openScreenshot(imageFile);
} catch (Throwable e) {
// Several error may come out with file handling or OOM
e.printStackTrace();
}
}
这就是你打开最近生成的图像的方法：
private void openScreenshot(File imageFile) {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(imageFile);
intent.setDataAndType(uri, "image/*");
startActivity(intent);
}
答案 1 :(得分：0)
试试这个， 在编写文件之前，您必须检查marshmallow的权限
public static final int REQUEST_STORAGE = 101;
if (Build.VERSION.SDK_INT >= 23) {
String[] PERMISSIONS = {android.Manifest.permission.WRITE_EXTERNAL_STORAGE};
if (!hasPermissions(mContext, PERMISSIONS)) {
ActivityCompat.requestPermissions((Activity) mContext, PERMISSIONS, REQUEST_STORAGE);
} else {
writeFile()
}
}
/*check permissions for marshmallow*/
@SuppressWarnings("BooleanMethodIsAlwaysInverted")
private static boolean hasPermissions(Context context, String... permissions) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
for (String permission : permissions) {
if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
}
return true;
}
/*get Permissions Result*/
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case REQUEST_STORAGE: {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d("TAG", "PERMISSION_GRANTED");
writeFile();
} else {
Toast.makeText(mContext, "The app was not allowed to write to your storage", Toast.LENGTH_LONG).show();
}
}
}
}
public void writeFile()
{
View v1 = L1.getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bm = v1.getDrawingCache();
BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
image = (ImageView) findViewById(R.id.ImageView02);
image.setBackgroundDrawable(bitmapDrawable);
Log.e("top-->", String.valueOf(bitmapDrawable));
bm.compress(Bitmap.CompressFormat.PNG,60,bytearrayoutputstream);
//String path = Environment.getExternalStorageDirectory().toString();
File myDir = new File(Environment.getExternalStorageDirectory(), "saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try
{
FileOutputStream out = new FileOutputStream(file);
bm.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
答案 2 :(得分：0)
final String root = Environment.getExternalStorageState().toString();
File myDir=new File(root + "/saved_images/" );
国家不存储。改为：
File myDir = new File(Environment.getExternalStorageDirectory(), "saved_images" );
并根据评论中的说明调整mkdirs的代码。
if (!myDir.exists())
{
if (!myDir.mkdirs())
{
Toast.makeText(this, "Sorry could not create directory:\n" + myDir.getAbsolutePath(), Toast.LENGTH_LONG).show();
return;
}
}
您抱怨该文件未创建，但它从目录开始。
你永远不会回答我关于Androud版本的问题。但是对于6.0及更高版本，您还应该询问用户是否有运行时权限。添加该代码。
或者，作为快速解决方案，请转到应用的Android设置，然后将存储切换按钮切换为开启。