如何将字符串 "A" 转换为 android 中的图像？

Question

我正在制作一个聊天应用程序。我有一个用于用户个人资料的图像视图。

如果用户图像是 null/empty，我想显示用户名的第一个字母，例如：假设用户名是 "UNKNOWN"，所以我想在该图像视图上只显示 U。
Click here to see sample of what I want

我试过了:

首先我检查了用户图片是否为空

  if (item.getSender_img_url() == null || item.getSender_img_url().isEmpty()||item.getSender_img_url().equals("null") ) {
                System.out.println(TAG + " photo is not available  ");

     //here i am getting first alphabet of Users Name 
                String[] result = item.getSenderName().split("\s+"); 
          // This is a regex for matching spaces
                // The string we'll create
                String abbrev = "";

                // Loop over the results from the string splitting
                for (int i = 0; i < result.length; i++) {

                    System.out.println(TAG + " abbrev 1 "+ abbrev);
                    // Grab the first character of this entry
                    char c = result[i].charAt(0);

                    System.out.println(TAG + " abbrev c "+ c);
                    // If its a number, add the whole number
                    if (c >= '0' && c <= '9') {
                        abbrev += result[i];
                    }

                    // If its not a number, just append the character
                    else {
                        abbrev += c;
                    }

                    System.out.println(TAG + " abbrev 3 "+ abbrev);
                }

               //here i am converting string value into image

                Bitmap bm = StringToBitMap(abbrev.toString());

               //here i am setting covertes bitmat image into  image view

                ((ViewHolder) holder).friends_image.setImageBitmap(bm);


    } else {
                System.out.println(TAG + " photo is available  ");
                try {
                    Picasso.with(mContext).load(item.getSender_img_url())
                            .error(R.drawable.profile_avatar)
                            .placeholder(R.drawable.profile_avatar).resize(40, 40).centerCrop()
                            .into(((ViewHolder) holder).friends_image);
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }







.................................

/**
     * @param encodedString
     * @return bitmap (from given string)
     */
    public static Bitmap StringToBitMap(String encodedString){
        try {
            byte [] encodeByte=Base64.decode(encodedString,Base64.DEFAULT);
            Bitmap bitmap=BitmapFactory.decodeByteArray(encodeByte, 0, encodeByte.length);
            return bitmap;
        } catch(Exception e) {
            e.getMessage();
            return null;
        }
    }

有什么帮助吗？

Answer 1

不应显示带字符串的图像，而应使用 View 和背景色，内部采用 TextView。像

<RelativeLayout ...
            ...>

    <TextView></TextView>

</RelativeLayout>

Answer 2

这个其实很简单。您可以将文本绘制到位图中。

Paint textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
textPaint.setColor(Color.BLACK);

Paint circlePaint = new Paint();
circlePaint.setColor(Color.GREEN);

int w = 30;  // Width of profile picture
int h = 30;  // Height of profile picture
Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
canvas.drawCircle(w/2, h/2, w/2, circlePaint);
canvas.drawText("A", 0, 0, textPaint);

您可以选择通过查找文字大小使其居中。接下来您要做的就是在 onDraw.

中将位图绘制到屏幕上 canvas

Answer 3

使用textview显示首字母并为其添加背景色。每次使用 Random class 获取随机颜色作为背景。

  private String senderFirstLetter;
        private TextView senderProfilePic;
// To retrieve first letter of the sender,
    senderFirstLetter = (String) holder.sender.getText().subSequence(0, 1);
            holder.senderProfilePic.setText(senderFirstLetter);
// To get random color 
    GradientDrawable drawable = (GradientDrawable) holder.senderProfilePic.getBackground();
            Random randomBackgroundColor = new Random();
            int color = Color.argb(255, randomBackgroundColor.nextInt(256), randomBackgroundColor.nextInt(256), randomBackgroundColor.nextInt(256));
            drawable.setColor(color);

如何将字符串 "A" 转换为 android 中的图像？

How to Convert String "A" into Image in android?

string

android

bitmap

imageview

dynamic-image-generation