Question

我setImageBitmap从网址到imageview。我只想定义高度，我希望应用程序按比例自动设置宽度。

这是我的代码：

URL imageURL = new URL("url");
HttpURLConnection connection = (HttpURLConnection) imageURL.openConnection();
InputStream inputStream = connection.getInputStream();
bitmap = BitmapFactory.decodeStream(inputStream);
image_projet.setImageBitmap(bitmap);

Answer 1

float aspect = bitmap.getWidth() / (float) bitmap.getHeight()
int newWidth = newHeight * aspect;

你自己可以计算新的宽度。

Answer 2

我仍然是Android的初学者。我很乐意接受批评。但这是我的答案。第一个答案是对的。以下是我在TextView上应用它的示例。

TextView name = (TextView)findViewById(R.id.name);
//this is where I got my bitmap. Not complete. This is inside AsyncTask
byte[] decodedString = Base64.decode(getBase64(jsonResult), Base64.DEFAULT);
Bitmap bitmap = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
/////

//here is His Code
int newHeight = 300; //I added this
float aspect = bitmap.getWidth() / (float) bitmap.getHeight() ;
float newWidth = newHeight * aspect;

//Now apply the it
name.setCompoundDrawablesWithIntrinsicBounds(null, new BitmapDrawable(getResources(),Bitmap.createScaledBitmap(bitmap,(int)newWidth,newHeight,true)), null, null);

无论如何，如果你觉得很难理解，这里是完整的源代码

MainActivity.java

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.*;
import android.graphics.drawable.BitmapDrawable;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Base64;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class MainActivity extends Activity {

    private ProgressDialog pd;
    String jsonResult="";
    TextView name;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        name = (TextView)findViewById(R.id.name);
        ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context
                .CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        if(networkInfo!=null && networkInfo.isConnected()){
            JasonReadTask jasonReadTask = new JasonReadTask();
            String url = "http://192.168.42.164/red_bank/android_connector/get_by_id.php?q=1"; //replace this URL accordingly
            jasonReadTask.execute(url);
        }
        else{
            Toast.makeText(this,"Not Connected", Toast.LENGTH_LONG).show();
        }

    }

    private class JasonReadTask extends AsyncTask<String, Void, String>{
        @Override
        protected void onPreExecute(){
            pd = new ProgressDialog(MainActivity.this);
            pd.setMessage("Please wait");
            pd.setIndeterminate(false);
            pd.setCancelable(false);
            pd.show();
        }
        @Override
        protected String doInBackground(String... params){
            HttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(params[0]);
            try{
                HttpResponse httpResponse = httpClient.execute(httpPost);
                jsonResult = inputStreamToString(httpResponse.getEntity().getContent()).toString();
            } catch (IOException e){
                Log.e("doInBackground", "IOException: " + e.getMessage());
            }
            return null;
        }
        @Override
        protected void onPostExecute(String result){
             pd.dismiss();
            byte[] decodedString = Base64.decode(getBase64(jsonResult), Base64.DEFAULT);
            Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
            float aspect = decodedByte.getWidth() / (float) decodedByte.getHeight() ;
            float newWidth = 300 * aspect;
            name.setCompoundDrawablesWithIntrinsicBounds(null, new BitmapDrawable(getResources(),Bitmap
                            .createScaledBitmap(decodedByte,(int)newWidth,300,false)), null, null);
        }
    }

    /*
     * Converts InputStream to String builder
     * for conversion to String.
     */
    private StringBuilder inputStreamToString(InputStream is){
        String rLine = "";
        //Converts Buffered data to String
        StringBuilder stringBuilder=new StringBuilder();
        //Reads the JSON data line by line
        BufferedReader rd=new BufferedReader(new InputStreamReader(is));

        try {
            while ((rLine=rd.readLine()) != null) {
                stringBuilder.append(rLine); //each line is appended into one file
            }
        }
        catch (IOException e) {
            Toast.makeText(getApplicationContext(),
                    "Error..." + e.toString(), Toast.LENGTH_LONG).show();
        }
        return stringBuilder;
    }

    /*
     * Get the base64 encoded image
     * and return it for Bitmap to ImageView Conversion
     */
    private String getBase64(String result){
        String base64="";
        try{
            JSONObject jsonObject = new JSONObject(result); //Get the Entire Object
            JSONArray jsonArray = jsonObject.optJSONArray("accounts"); //Interpret the Object 
            // into array
            JSONObject jasonData = jsonArray.getJSONObject(0); //Get specific row
            base64 = jasonData.optString("profile"); //getSpecific data
            name.setText(jasonData.optString("full_name"));
        } catch(JSONException e){
            e.getMessage();
            Log.e("getBase64", "JSONException: " + e.getMessage());
        }
        return  base64;
    }

}

这是布局

<!--activity_main.xml-->
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <TextView
            android:layout_width="300dp"
            android:layout_height="300dp"
            android:text="Not Connected"
            android:id="@+id/name" android:layout_gravity="center_horizontal" android:textSize="24sp" />
</LinearLayout>

Android Java：位图调整大小定义高度和宽度自动

2 个答案: