ImageView imageView = findViewById(R.id.imageView); imageView.setImageBitmap(imageBitmap); } }这两句是什么意思
时间: 2023-06-08 15:07:44 浏览: 149
这两句是针对 Android 应用程序中的 ImageView 控件和图片 Bitmap 对象的操作。第一句是通过 findViewById 方法获取布局文件中定义的 ImageView 控件,并将其赋值给变量 imageView。第二句是设置 ImageView 控件的显示内容为指定的 imageBitmap 图片。具体来说,这里的 imageBitmap 可以通过一些方法,比如从网络或本地文件中获取图片,并通过 Bitmap 对象进行处理和显示。
相关问题
Android studio 拍照后图片在imageview显示出来
可以使用以下代码在Android中拍照并将图像显示在ImageView上:
```java
// 在AndroidManifest.xml中添加Camera权限
<uses-permission android:name="android.permission.CAMERA" />
// MainActivity.java文件中的代码
public class MainActivity extends AppCompatActivity {
private ImageView imageView;
static final int REQUEST_IMAGE_CAPTURE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = findViewById(R.id.imageView);
//监听按钮点击事件
Button takePhotoButton = findViewById(R.id.button);
takePhotoButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
dispatchTakePictureIntent();
}
});
}
// 适用于拍照的Intent
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
// 拍照后显示图片在ImageView上
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
Bundle extras = data.getExtras();
Bitmap imageBitmap = (Bitmap) extras.get("data");
imageView.setImageBitmap(imageBitmap);
}
}
}
```
这段代码将启动相机应用程序,并等待您拍照。在用户拍照后,使用 `onActivityResult()` 将图像显示在 ImageView 中。
Android studio调用相机拍照并显示到ImageView中
好的,下面是实现的步骤:
1.在AndroidManifest.xml文件中添加相机权限
```
<uses-permission android:name="android.permission.CAMERA" />
```
2.在布局文件中添加ImageView和Button控件
```
<ImageView
android:id="@+id/imageView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="@drawable/ic_image_placeholder" />
<Button
android:id="@+id/buttonCapture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Capture" />
```
3.在Activity中获取相机权限,并设置Button的点击事件
```
public class MainActivity extends AppCompatActivity {
private static final int REQUEST_IMAGE_CAPTURE = 1;
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = findViewById(R.id.imageView);
Button buttonCapture = findViewById(R.id.buttonCapture);
buttonCapture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.CAMERA}, REQUEST_IMAGE_CAPTURE);
} else {
dispatchTakePictureIntent();
}
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == REQUEST_IMAGE_CAPTURE) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
dispatchTakePictureIntent();
} else {
Toast.makeText(this, "Camera permission denied", Toast.LENGTH_SHORT).show();
}
}
}
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
Bundle extras = data.getExtras();
Bitmap imageBitmap = (Bitmap) extras.get("data");
imageView.setImageBitmap(imageBitmap);
}
}
}
```
4.运行程序,点击按钮将会打开相机拍照,照片将会显示在ImageView中。
注意:以上代码仅为演示如何使用相机拍照并显示到ImageView中,实际使用中还需要处理异常情况和兼容性问题。