如下是我现在GridView加载图片和文字的方式，如果图片不在资源里面，存在手机本地路径，要怎么改才能加载图片。
自己试了试发现把map.put("img", img[i]);改成map.put("img", Uri.parse("file://" + file));就可以，直接把文件路径放进去。虽然我也不知道这样做的原理是什么，有人解惑么。
public class MainActivity extends AppCompatActivity {
private GridView grid_test;
private List<Map<String,Object>> dataList;
private SimpleAdapter simpleAdapter;
private int[] img = {R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round, R.mipmap.ic_launcher,
R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,
R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,
R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,
R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,
R.mipmap.ic_launcher_round,R.mipmap.ic_launcher,R.mipmap.ic_launcher_round,R.mipmap.ic_launcher};
private String[] imgName = {"1","2","3","4",
"5","6","7","8",
"9","10","11","12",
"13","14","15","16",
"17","18","19","20",
"21","22","23","24"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
grid_test = (GridView) findViewById(R.id.grid_test);
dataList = new ArrayList<Map<String, Object>>();
simpleAdapter = new SimpleAdapter(this,getData(),R.layout.grid_item,
new String[] {"img","txt"},new int[]{R.id.img_item,R.id.txt_item});
grid_test.setAdapter(simpleAdapter);
}
private List<Map<String,Object>> getData() {
for (int i=0; i<img.length; i++) {
Map<String,Object> map = new HashMap<String, Object>();
map.put("img", img[i]);
map.put("txt", imgName[i]);
dataList.add(map);
}
return dataList;
}
}
这个很简单，如果改成map.put("img", Uri.parse("file://" + file)); SimpleAdatper绑定数据的时候会调用ImageView的setImageURI()，将你的uri传进去,
ImageView会自动从文件里解析流还获取对应的Bitmap。
public class GridActivity extends Activity {
List<MyClass> list = new ArrayList<MyClass>();
private GridView grid_test;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_grid);
initList();
grid_test = (GridView) findViewById(R.id.grid_test);
grid_test.setAdapter(new MyAdapter());
}
private void initList() {
list.add(new MyClass("1", getBMP("test.png")));
list.add(new MyClass("2", getBMP("test.png")));
list.add(new MyClass("3", getBMP("test.png")));
list.add(new MyClass("4", getBMP("test.png")));
list.add(new MyClass("5", getBMP("test.png")));
list.add(new MyClass("6", getBMP("test.png")));
list.add(new MyClass("7", getBMP("test.png")));
list.add(new MyClass("8", getBMP("test.png")));
list.add(new MyClass("9", getBMP("test.png")));
}
private Bitmap getBMP(String file) {
try {
FileInputStream is = new FileInputStream(Environment.getExternalStorageDirectory() + "/" + file);
Bitmap bmp = BitmapFactory.decodeStream(is);
return bmp;
} catch (Exception e) {
}
return null;
}
private class MyClass {
String name;
Bitmap img;
public MyClass(String name, Bitmap img) {
this.name = name;
this.img = img;
}
}
private class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int arg0) {
return null;
}
@Override
public long getItemId(int arg0) {
return 0;
}
@Override
public View getView(int position, View arg1, ViewGroup arg2) {
View view = getLayoutInflater().inflate(R.layout.grid_item, null);
TextView tv = (TextView) view.findViewById(R.id.txt_item);
tv.setText(list.get(position).name);
ImageView img = (ImageView) view.findViewById(R.id.img_item);
img.setImageBitmap(list.get(position).img);
return view;
}
}
}
从数据库读出你的路径，添加到GridView'中的图片列中DataImageUrlField列上.
通过适配器来SimpleAdapter dAdapter = new SimpleAdapter(MainActivity.this,
listmage, R.layout.activity_main, from, to);//listmage是arrylist数字保存的路径,然后设置显示的用ImageView在布局文件添加，然后设置int to[]={R.id.ImageView};
只要知道本地手机每张图片的路径phonePicPath，每张图片都可以Bitmap bitmap = BitmapFactory.decodeFile(phonePicPath);
String img_url = uri.getPath();//这是本机的图片路径
ContentResolver cr = this.getContentResolver();
Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));
imageView.setImageBitmap(bitmap);
自己试了试发现把map.put("img", img[i]);改成map.put("img", Uri.parse("file://" + file));就可以，直接把文件路径放进去。虽然我也不知道这样做的原理是什么，有人解惑么。