Question

package com.example.sugandhabansal.gallerypickimage;

import android.content.Intent;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
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.ImageView;

public class MainActivity extends AppCompatActivity {
    private static final int SELECTED_PIC = 1;
    ImageView imageView;

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


        imageView = (ImageView) findViewById(R.id.imageView);
    }

    public void btnClick(View v) {
        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        startActivityForResult(intent, SELECTED_PIC);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case SELECTED_PIC:
                if (resultCode == RESULT_OK) {
                    Uri uri = data.getData();
                    String[] projection = {MediaStore.Images.Media.DATA};

                    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
                    cursor.moveToFirst();

                    int columnIndex = cursor.getColumnIndex(projection[0]);
                    String filepath = cursor.getString(columnIndex);
                    cursor.close();

                    Bitmap bitmap = BitmapFactory.decodeFile(filepath);
                    Drawable drawable = new BitmapDrawable(Resources.getSystem(), bitmap);
                    imageView.setBackground(drawable);
                }
                break;
            default:
                break;
        }
    }
}

这是MainActivity.java文件。代码基本上从库中加载图像并将其显示在布局的imageview部分中。当我在我的智能手机上运行apk时，在选择之后在imageview部分中没有看到图像，并且在调试之后看到位图等于null。有人可以帮助我解决这个问题，因为我无法解决这个问题。

Answer 1

确保获取的文件路径是有效路径。
确保您具有访问存储空间的权限。

如果上面的内容没问题且你仍然得到null结果，请尝试以下代码：

Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri));

bitmapFactory.decodefile将null作为输出

1 个答案: