java - picasso 图书馆不显示来自 URL 的图像

Question

我正在使用 Picasso Library，但使用 Picasso.with(this).load(url).into(iv);
我没有在我的 View 中找到任何图像......

MainActivity.java

package com.example.gallery;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.os.Build;

import com.squareup.picasso.Picasso;


public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageView iv = (ImageView) findViewById(R.id.imageView1);
        String url="http://upload.wikimedia.org/wikipedia/commons/2/2a/Junonia_lemonias_DSF_upper_by_Kadavoor.JPG";
        Picasso.with(this).load(url).into(iv);


        /*
         * if (savedInstanceState == null) {

            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();

        }*/
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);


            return rootView;
        }
    }

}

和activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="400dp"
    android:layout_weight="0.52"
    android:text="Button" />

<ImageView
    android:id="@+id/imageView1"
    android:layout_width="wrap_content"
    android:layout_height="183dp"
    android:layout_weight="2.89"
    android:src="@drawable/abc_ab_solid_light_holo" />

我正确地查看了按钮，但我没有查看 url 的图像。

一些提示？谢谢

Answer 1

如果在获取图像时出现任何错误，请使用它....

 Picasso.with(context)
    .load(url)
    .placeholder(R.drawable.user_placeholder)
    .error(R.drawable.user_placeholder_error)
    .into(imageView);

在线性布局中放置方向。

Additional documentation on Picasso