android学习之选择媒体库中的图片

长平狐 发布于 2012/10/08 15:24
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从媒体库中选择图片

主要是启动系统相关Activity

Intent i = new Intent( Intent.ACTION_PICK,

android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

startActivityForResult(i, RESULT_LOAD_IMAGE);

注意:这里要传一个整形的常量RESULT_LOAD_IMAGEstartActivityForResult()方法。

一旦用户选择了一张图片,onActivityResult()方法将会被调用。我们需要处理这个方法得到的数据。onActivityResult()方法只有当图片被选中后才会调用。在这个方法中,我们需要检查requestCode是否是我们之前传给startActivityForResult()方法的RESULT_LOAD_IMAGE。

Java代码:

package com.example.com.njupt.zhb.selectimages;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
 
    private static int RESULT_LOAD_IMAGE = 123;
    private ImageView imageView;
    private String picturePath=null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView = (ImageView) findViewById(R.id.imgView);
        Button buttonLoadImage = (Button) findViewById(R.id.buttonLoadPicture);
        buttonLoadImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
 
                Intent i = new Intent(
                        Intent.ACTION_PICK,
                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
 
                startActivityForResult(i, RESULT_LOAD_IMAGE);
            }
        });
    }
 
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
 
        if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };
 
            Cursor cursor = getContentResolver().query(selectedImage,
                    filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            picturePath = cursor.getString(columnIndex);
            cursor.close();
            imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

XML布局文件

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
    android:id="@+id/widget0"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView
    android:id="@+id/imgView"
    android:layout_width="315dp"
    android:layout_height="384dp"
    android:layout_x="2dp"
    android:layout_y="4dp" />
<Button
    android:id="@+id/buttonLoadPicture"
    android:layout_width="317dp"
    android:layout_height="wrap_content"
    android:text="SelectImage"
    android:layout_x="2dp"
    android:layout_y="391dp" />
</AbsoluteLayout>






原文链接:http://blog.csdn.net/nuptboyzhb/article/details/7844076
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