android点击查看大图（长按保存图片）

分手后的思念是犯贱 2022-05-19 09:38 620阅读 0赞

通常会看到点击ImageView弹出一个Dialog上面有一张大图，然后长按大图可以保存，这就好像成为了一个固定的

流程，那么，我们就来实现这一系列的功能。

1.xml文件，特别简单，只有一个ImageView:

1.  `<?xml version="1.0" encoding="utf-8"?>`
2.  `<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"`
3.  `xmlns:tools="http://schemas.android.com/tools"`
4.  `android:id="@+id/activity_main"`
5.  `android:layout_width="match_parent"`
6.  `android:layout_height="match_parent"`
7.  `android:paddingBottom="@dimen/activity_vertical_margin"`
8.  `android:paddingLeft="@dimen/activity_horizontal_margin"`
9.  `android:paddingRight="@dimen/activity_horizontal_margin"`
10. `android:paddingTop="@dimen/activity_vertical_margin"`
11. `tools:context="visahall.cn.testsavebitmap.MainActivity">`
12.  
13. `<ImageView`
14. `android:id="@+id/image"`
15. `android:src="@mipmap/riven"`
16. `android:layout_centerInParent="true"`
17. `android:layout_width="100dp"`
18. `android:layout_height="100dp" />`
19.  
20. `</RelativeLayout>`

2.MainActivity:

1.  `public class MainActivity extends AppCompatActivity {`
2.   
3.  `private ImageView imageView;`
4.  `private Dialog dialog;`
5.  `private ImageView mImageView;`
6.   
7.  `@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)`
8.  `@Override`
9.  `protected void onCreate(Bundle savedInstanceState) {`
10. `super.onCreate(savedInstanceState);`
11. `setContentView(R.layout.activity_main);`
12.  
13. `init();`
14.  
15. `//小图的点击事件（弹出大图）`
16. `imageView.setOnClickListener(new View.OnClickListener() {`
17. `@Override`
18. `public void onClick(View v) {`
19. `dialog.show();`
20. `}`
21. `});`
22.  
23. `}`
24.  
25. `private void init() {`
26. `imageView = (ImageView) findViewById(R.id.image);`
27. `//大图所依附的dialog`
28. `dialog = new Dialog(MainActivity.this, R.style.AlertDialog_AppCompat_Light_);`
29. `mImageView = getImageView();`
30. `dialog.setContentView(mImageView);`
31.  
32. `//大图的点击事件（点击让他消失）`
33. `mImageView.setOnClickListener(new View.OnClickListener() {`
34. `@Override`
35. `public void onClick(View v) {`
36. `dialog.dismiss();`
37. `}`
38. `});`
39.  
40. `//大图的长按监听`
41. `mImageView.setOnLongClickListener(new View.OnLongClickListener() {`
42. `@Override`
43. `public boolean onLongClick(View v) {`
44. `//弹出的“保存图片”的Dialog`
45. `AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);`
46. `builder.setItems(new String[]{getResources().getString(R.string.save_picture)}, new DialogInterface.OnClickListener() {`
47. `@Override`
48. `public void onClick(DialogInterface dialog, int which) {`
49. `saveCroppedImage(((BitmapDrawable) mImageView.getDrawable()).getBitmap());`
50. `}`
51. `});`
52. `builder.show();`
53. `return true;`
54. `}`
55. `});`
56. `}`
57.  
58. `//保存图片`
59. `private void saveCroppedImage(Bitmap bmp) {`
60. `File file = new File("/sdcard/myFolder");`
61. `if (!file.exists())`
62. `file.mkdir();`
63.  
64. `file = new File("/sdcard/temp.jpg".trim());`
65. `String fileName = file.getName();`
66. `String mName = fileName.substring(0, fileName.lastIndexOf("."));`
67. `String sName = fileName.substring(fileName.lastIndexOf("."));`
68.  
69. `// /sdcard/myFolder/temp_cropped.jpg`
70. `String newFilePath = "/sdcard/myFolder" + "/" + mName + "_cropped" + sName;`
71. `file = new File(newFilePath);`
72. `try {`
73. `file.createNewFile();`
74. `FileOutputStream fos = new FileOutputStream(file);`
75. `bmp.compress(Bitmap.CompressFormat.JPEG, 50, fos);`
76. `fos.flush();`
77. `fos.close();`
78. `} catch (IOException e) {`
79. `// TODO Auto-generated catch block`
80. `e.printStackTrace();`
81. `}`
82. `}`
83.  
84. `//动态的ImageView`
85. `private ImageView getImageView(){`
86. `ImageView iv = new ImageView(this);`
87. `//宽高`
88. `iv.setLayoutParams(new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));`
89. `//设置Padding`
90. `iv.setPadding(20,20,20,20);`
91. `//imageView设置图片`
92. `InputStream is = getResources().openRawResource(R.mipmap.riven);`
93. `Drawable drawable = BitmapDrawable.createFromStream(is, null);`
94. `iv.setImageDrawable(drawable);`
95. `return iv;`
96. `}`
97.  
98. `}`

# [Demo下载][Demo] #

[Demo]: https://download.csdn.net/download/zhw0596/10559733