Android基礎教程：簡易的文件對話框

1.對話框布局文件

注釋部分為預留，如果是OpenFileDialog，在此處加入TextView用來顯示當前目錄，如果是SaveFileDialog，加入EditView用來輸入要保存的文件名。

1. <?xml version="1.0" encoding="utf-8"?>
2. <LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"
3. android:orientation="vertical"
4. android:layout_width="fill_parent"
5. android:layout_height="fill_parent">
7. <LinearLayout android:orientation="horizontal"
8. android:layout_width="fill_parent"
9. android:layout_height="40dip">
11. <Button android:layout_width="40dip"
12. android:layout_height="40dip"
13. android:id="@+id/FileChooserHomeBtn"
14. android:text="Home"
15. android:layout_weight="1"/>
17. <LinearLayout android:layout_width="140dip"
18. android:layout_height="35dip"
19. android:id="@+id/FileChooserDirLayout"
20. android:gravity="center"
21. android:layout_weight="1">
23. <!-- <TextView android:layout_width="140dip"
24. android:layout_height="35dip"
25. android:id="@+id/dir_str"
26. android:gravity="center"
27. android:layout_weight="1"/> -->
29. </LinearLayout>
31. <Button android:layout_width="40dip"
32. android:layout_height="40dip"
33. android:id="@+id/FileChooserBackBtn"
34. android:text="Back"
35. android:layout_weight="1"/>
37. </LinearLayout>
39. <ListView android:layout_width="fill_parent"
40. android:layout_height="300dip"
41. android:id="@+id/FileChooserDirList"/>
43. <Button android:layout_width="fill_parent"
44. android:layout_height="wrap_content"
45. android:id="@+id/FileChooserOkBtn"
46. android:text="OK"/>
48. <Button android:layout_width="fill_parent"
49. android:layout_height="wrap_content"
50. android:id="@+id/FileChooserCancelBtn"
51. android:text="Cancel"/>
53. </LinearLayout>

2.Dialog的java文件

1. import java.io.File;
2. import java.util.ArrayList;
3. import java.util.List;
5. import android.app.Dialog;
6. import android.content.Context;
7. import android.os.Bundle;
8. import android.os.Environment;
9. import android.os.Handler;
10. import android.view.Gravity;
11. import android.view.View;
12. import android.widget.AdapterView;
13. import android.widget.AdapterView.OnItemClickListener;
14. import android.widget.ArrayAdapter;
17. /**
18. *
19. *
20. *
21. * @author
22. *
23. */
24. public class FileOpenerDialog extends Dialog implements android.view.View.OnClickListener {
26. private android.widget.ListView list;
27. ArrayAdapter<String> Adapter;
28. ArrayList<String> arr = new ArrayList<String>();
30. Context context;
31. private String path;
33. private android.widget.TextView curFilePath;
34. private android.widget.EditText saveFileName;
35. private android.widget.Button home, back, ok, cancel;
36. private android.widget.LinearLayout layout;
38. private int type = 1;
39. private String[] fileType = null;
41. public final static int TypeOpen = 1;
42. public final static int TypeSave = 2;
44. private MyDialogListener listener;
46. /**
47. * @param context
48. * @param 值為1表示OpenFileDialog, 值為2表示SaveFileDialog
49. * @param 需要過濾的文件類型，若為空表示只顯示文件夾
50. * @param 初始路徑，這個有問題
51. */
52. public FileOpenerDialog(Context context, int type, String[] fileType, String resultPath,
53. MyDialogListener listener) {
54. super(context);
55. // TODO Auto-generated constructor stub
56. this.context = context;
57. this.type = type;
58. this.fileType = fileType;
59. this.path = resultPath;
60. this.listener = listener;
61. }
63. @Override
64. public void dismiss() {
65. // TODO Auto-generated method stub
66. super.dismiss();
67. }
69. @Override
70. protected void onCreate(Bundle savedInstanceState) {
71. // TODO Auto-generated method stub
72. super.onCreate(savedInstanceState);
73. setContentView(R.layout.dialog_filechooser);
75. path = getSDPath();
76. arr = (ArrayList<String>)getDirs(path);
77. Adapter = new ArrayAdapter<String>(context, android.R.layout.simple_list_item_1, arr);
79. list = (android.widget.ListView)findViewById(R.id.FileChooserDirList);
80. list.setAdapter(Adapter);
81. list.setOnItemClickListener(lvLis);
83. home = (android.widget.Button)findViewById(R.id.FileChooserHomeBtn);
84. home.setOnClickListener(this);
86. back = (android.widget.Button)findViewById(R.id.FileChooserBackBtn);
87. back.setOnClickListener(this);
89. ok = (android.widget.Button)findViewById(R.id.FileChooserOkBtn);
90. ok.setOnClickListener(this);
92. cancel = (android.widget.Button)findViewById(R.id.FileChooserCancelBtn);
93. cancel.setOnClickListener(this);
95. layout = (android.widget.LinearLayout)findViewById(R.id.FileChooserDirLayout);
97. if(type == TypeOpen)
98. {
99. // 若為OpenFileDialog，在預留的位置添加TextView，顯示當前路徑
100. curFilePath = new android.widget.TextView(context);
101. layout.addView(curFilePath);
102. curFilePath.setText(path);
103. }
104. else if(type == TypeSave)
105. {
106. // 若為SaveFileDialog，在預留的位置添加EditText，輸入要保存的文件名
107. saveFileName = new android.widget.EditText(context);
108. saveFileName.setWidth(240);
109. saveFileName.setHeight(70);
110. saveFileName.setGravity(Gravity.CENTER);
111. saveFileName.setPadding(0, 2, 0, 0);
112. layout.addView(saveFileName);
113. saveFileName.setText("Enter file name");
114. }
115. }
117. // 自動更新ListView內容
118. Runnable add = new Runnable() {
119. @Override
120. public void run() {
121. // TODO Auto-generated method stub
122. arr.clear();
123. List<String> temp = getDirs(path);
124. for(int i = 0; i < temp.size(); i++) arr.add(temp.get(i));
125. Adapter.notifyDataSetChanged();
126. }
127. };
129. // 事件監聽，當點擊ListView的某個項目時觸發
130. private OnItemClickListener lvLis = new OnItemClickListener() {
131. @Override
132. public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
133. String temp = (String)arg0.getItemAtPosition(arg2);
134. if(temp.equals("..")) path = getSubDir(path); // 如果點擊的項目是".."，表示沒有子目錄，返回上一級目錄
135. else if(path.equals("/")) path = path + temp; // 如果當前目錄為根目錄，直接添加子目錄，例 "/" -> "/sdcard"
136. else path = path + "/" + temp; // 將子目錄追加到當前目錄後，例 "/sdcard" -> "/sdcard/xml"
137. if(type == TypeOpen) curFilePath.setText(path);
138. Handler handler = new Handler();
139. handler.post(add);// 因為當前目錄改變，更新子文件夾
140. }
141. };
143. /**
144. * Get sub directories
145. * @param ipath
146. * @return
147. */
148. private List<String> getDirs(String ipath) {
149. List<String> dirs = new ArrayList<String>();
150. File[] files = new File(ipath).listFiles();
151. if(files != null)
152. {
153. for(File f: files)
154. {
155. if(f.isDirectory())
156. {
157. String tmp = f.toString();
158. if(tmp.endsWith("/")) tmp = tmp.substring(0, tmp.length() - 1);
159. int pos = tmp.lastIndexOf("/");
160. dirs.add(tmp.substring(pos + 1, tmp.length()));
161. }
162. else if(f.isFile() && fileType != null)
163. {
164. for(int i = 0; i< fileType.length; i++)
165. {
166. int typeStrLen = fileType[i].length();
167. String fileName = f.getPath().substring(f.getPath().length() - typeStrLen);
168. if (fileName.equalsIgnoreCase(fileType[i]))
169. dirs.add(f.toString().substring(path.length() + 1, f.toString().length()));
170. }
171. }
172. }
173. }
174. if(dirs.size() == 0) dirs.add("..");
175. return dirs;
176. }
178. @Override
179. public void onClick(View args0) {
180. // TODO Auto-generated method stub
181. if(args0.getId() == home.getId())
182. {
183. // 點擊"Home"按鈕，回到根目錄
184. path = getRootDir();
185. if(type == TypeOpen) curFilePath.setText(path);
186. Handler handler = new Handler();
187. <span style="white-space:pre"> </span>handler.post(add); // 更新子文件夾
188. }
189. else if(args0.getId() == back.getId())
190. {
191. // 點擊"Back"按鈕，返回上一級文件夾
192. path = getSubDir(path);
193. if(type == TypeOpen) curFilePath.setText(path);
194. Handler handler = new Handler();
195. handler.post(add); // 更新子文件夾
196. }
197. else if(args0.getId() == ok.getId())
198. {
199. // 點擊"OK"按鈕，關閉對話框，調用自定義監視器的OnOKClick方法，將當前目錄返回主Activity
200. dismiss();
201. listener.OnOkClick(path);
202. }
203. else if(args0.getId() == cancel.getId())
204. {
205. // 點擊"Cancel”按鈕
206. this.cancel();
207. }
208. }
210. /**
211. * Get SD card directory, if SD card not exist, return '/'
212. * @return
213. */
214. private String getSDPath() {
215. File sdDir = null;
216. boolean sdCardExist = Environment.getExternalStorageState()
217. .equals(android.os.Environment.MEDIA_MOUNTED); // 判斷是否存在SD卡
218. if(sdCardExist)
219. {
220. sdDir = Environment.getExternalStorageDirectory(); // 如果SD卡存在，返回SD卡的目錄
221. }
222. if(sdDir == null)
223. {
224. return "/"; // 如果SD卡不存在，返回根目錄
225. }
226. return sdDir.toString();
227. }
229. private String getRootDir() {
230. return "/";
231. }
233. /**
234. * Get upper directory
235. * @param path
236. * @return
237. */
238. private String getSubDir(String path) {
239. String subpath = "/";
240. if(path.endsWith("/"))
241. {
242. path = path.substring(0, path.length() - 1);
243. }
244. int pos = path.lastIndexOf("/");
245. if(pos > 0)
246. {
247. subpath = path.substring(0, pos);
248. }
249. return subpath;
250. }
251. }