public void handleActivityResult(int requestCode, int resultCode, Intent data) { // 处理ActivityResult的逻辑 ImageView imageView= imageView.findViewById(R.id.book_cover); if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) { Uri uri = data.getData(); try { Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri); // 将图片显示在 ImageView 控件中 imageView.setImageBitmap(bitmap); } catch (IOException e) { e.printStackTrace(); } } }怎样实现imageview的实例化
时间: 2023-06-19 17:06:25 浏览: 40
在上述代码中,实例化 ImageView 的语句应该是:
```
ImageView imageView = findViewById(R.id.imageView);
```
其中,`R.id.imageView` 是指布局文件中标识 ImageView 控件的 id。您需要在布局文件中给 ImageView 控件设定一个 id,例如:
```
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/default_image" />
```
这个例子中,ImageView 控件的 id 为 `imageView`。您可以根据实际情况修改这个 id。在实例化时,使用 `findViewById` 方法获取布局文件中对应 id 的控件实例。
相关问题
package com.example.dzy; import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button btnLogin,btnRegister; private ImageView ivLogin; private TextView tvUsername,tvUserId; private static final int REQUEST_REGISTER_CODE=1; private static final int REQUEST_LOGIN_CODE=2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tvUserId=findViewById(R.id.tv_main_userid); tvUsername=findViewById(R.id.tv_main_username); ivLogin=findViewById(R.id.iv_login); btnLogin=findViewById(R.id.btn_main_login); btnRegister=findViewById(R.id.btn_main_register); btnLogin.setOnClickListener(this); btnRegister.setOnClickListener(this); } @Override public void onClick(View view){ Intent intent=new Intent(); switch (view.getId()){ case R.id.btn_main_login: intent.setClass(this,LoginActivity.class); startActivityForResult(intent,REQUEST_LOGIN_CODE); break; case R.id.btn_main_register: intent.setClass(this,RegisterActivity.class); startActivityForResult(intent,REQUEST_REGISTER_CODE); break; } } @Override protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent intent){ super.onActivityResult(requestCode,resultCode,intent); if(intent==null){ return; } switch (requestCode){ case REQUEST_REGISTER_CODE: if (resultCode==11){ tvUserId.setText(intent.getStringExtra("userId")); tvUsername.setText(intent.getStringExtra("userName")); ivLogin.setImageResource(R.mipmap.user_2); Toast.makeText(this,"注册成功!",Toast.LENGTH_LONG).show(); Intent intent1=new Intent(this,NavigationActivity.class); }else{ Toast.makeText(this,"注册失败!",Toast.LENGTH_LONG).show(); } break; case REQUEST_LOGIN_CODE: if(resultCode==21){ tvUserId.setText(intent.getStringExtra("userId")); tvUsername.setText(intent.getStringExtra("userName")); ivLogin.setImageResource(R.mipmap.user_2); Toast.makeText(this,"登录成功!",Toast.LENGTH_LONG).show(); Intent intent1=new Intent(this,NavigationActivity.class); }else{ Toast.makeText(this,"登录失败!",Toast.LENGTH_LONG).show(); } break; default: Toast.makeText(this,"操作失败!",Toast.LENGTH_LONG).show(); break; } } }这段中intent1没有进行页面跳转
是的,您是正确的。在代码中,虽然创建了一个新的 `Intent` 对象 `intent1`,但是没有将其用于页面跳转。您需要在 `case` 语句中添加页面跳转代码,例如:
```
case REQUEST_REGISTER_CODE:
if (resultCode==11){
tvUserId.setText(intent.getStringExtra("userId"));
tvUsername.setText(intent.getStringExtra("userName"));
ivLogin.setImageResource(R.mipmap.user_2);
Toast.makeText(this,"注册成功!",Toast.LENGTH_LONG).show();
Intent intent1=new Intent(this,NavigationActivity.class);
startActivity(intent1); // 添加这行代码进行页面跳转
}else{
Toast.makeText(this,"注册失败!",Toast.LENGTH_LONG).show();
}
break;
case REQUEST_LOGIN_CODE:
if(resultCode==21){
tvUserId.setText(intent.getStringExtra("userId"));
tvUsername.setText(intent.getStringExtra("userName"));
ivLogin.setImageResource(R.mipmap.user_2);
Toast.makeText(this,"登录成功!",Toast.LENGTH_LONG).show();
Intent intent1=new Intent(this,NavigationActivity.class);
startActivity(intent1); // 添加这行代码进行页面跳转
}else{
Toast.makeText(this,"登录失败!",Toast.LENGTH_LONG).show();
}
break;
```
这样,当用户注册或者登录成功时,就会跳转到 `NavigationActivity` 页面。
请解释以下代码@SuppressLint("SetTextI18n") protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) { super.onActivityResult(requestCode, resultCode, data); ImageView img_result=(ImageView) findViewById(R.id.pic); switch (requestCode) { case TAKE_PHOTO: if (resultCode == RESULT_OK) { //将图片解析成Bitmap对象,并把它显现出来 // String filePath = getFilesDir().getAbsolutePath()+"/image.jpeg"; // bitmap = BitmapFactory.decodeFile(filePath); //注意bitmap,后面再decode就会为空 try { bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri)); } catch (FileNotFoundException e) { e.printStackTrace(); } // bitmap = BitmapFactory.decodeFile(picpath); picpath=imageUri.getPath().toString(); Log.e("", imageUri.getAuthority()); Log.e("picpath",picpath); @SuppressLint("SdCardPath") String fileName = picpath; img_result.setImageBitmap(bitmap); img_result.invalidate(); } break; case SCAN_OPEN_PHONE: if (resultCode == RESULT_OK){ Uri selectImage=data.getData(); String[] FilePathColumn={MediaStore.Images.Media.DATA}; Cursor cursor = getContentResolver().query(selectImage, FilePathColumn, null, null, null); cursor.moveToFirst(); //从数据视图中获取已选择图片的路径 int columnIndex = cursor.getColumnIndex(FilePathColumn[0]); picpath = cursor.getString(columnIndex); Log.e("picpath",picpath); cursor.close(); bitmap = BitmapFactory.decodeFile(picpath); img_result.setImageBitmap(bitmap); img_result.invalidate(); } break; default: break; } },并说明如何把得到的照片上传到mysql中
这段代码是在处理Android中的相机和相册的操作,根据requestCode的不同,分别处理拍照和选择相册的情况。其中,将得到的照片解析成Bitmap对象,并显示在ImageView中。
要将得到的照片上传到MySQL中,需要先将Bitmap对象转换成字节数组,然后将字节数组上传到服务器。具体实现可以参考以下步骤:
1. 将Bitmap对象转换成字节数组:
```
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] imageBytes = baos.toByteArray();
```
2. 将字节数组上传到服务器:
可以使用HttpURLConnection或者OkHttp等网络库进行上传,具体实现可以参考以下代码:
```
URL url = new URL("http://yourserver.com/upload.php");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/octet-stream");
conn.setRequestProperty("Content-Length", String.valueOf(imageBytes.length));
OutputStream os = conn.getOutputStream();
os.write(imageBytes);
os.flush();
os.close();
```
其中,upload.php是服务器端的脚本,用于接收上传的字节数组并保存到MySQL中。