android - 如何使用 JDBC Drive 将 MySql 表图像 (BLOB) 加载到 ImageView

Question

我有一个项目正在进行中。在这个项目中，我试图通过 JDBC 驱动程序将登录用户图像从 MySQL 表中获取到 ImageView，在这种情况下，图像加载一次，如果我尝试加载图片，则系统会在错误之后出现错误如果我再次尝试加载图像，则图像将加载到 ImageView 中。我在这里附上代码。

private class findpicture extends  AsyncTask<String, String, String> {

    String msg;
    String searchtext= textView3.getText().toString();

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        Toast.makeText(getApplicationContext(), "Searching username", Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_SHORT).show();
        textView3.setText("");
    }

    @Override
    protected String doInBackground(String... strings) {

        try{

            Class.forName("com.mysql.jdbc.Driver");
            Connection con = (Connection)DriverManager.getConnection(url,user,pass);

            if (con == null){
                msg="Connection error...";
            }else{
                byte b[];
                Blob blob;
                Statement statement= (Statement) con.createStatement();
                ResultSet resultSet = statement.executeQuery("select * from userlogin where name='"+searchtext+"'");

                while (resultSet.next()){
                    blob = resultSet.getBlob("image");
                    b= blob.getBytes(1, (int)blob.length());
                    Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0, b.length);
                    savedphoto.setImageBitmap(bitmap);
                    }
                msg= "user image saved successfully...";

            }

        }catch (Exception e){
            msg="unknown error..."+e;

            System.out.println(e.toString());
        }

        return null;
    }
}

Error Code android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

Answer 1

你有一个 Thread 冲突，你需要重新检查那里的调用和同步任务， 快速解决您的问题

runOnUiThread(new Runnable() {
    @Override
    public void run() {
        new findpicture().execute();
    }
});